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Modified natural cycle for embryo transfer using frozen-thawed blastocysts: A satisfactory option
Accepted Manuscript Title: Modified natural cycle for embryo transfer using frozen-thawed blastocysts: a satisfactory option Authors: Quoc V. Le, Sina Abhari, Omar M. Abuzeid, Jennifer DeAnna, Mohamed A. Satti, Tarek Abozaid, Iqbal Khan, Mostafa I. Abuzeid PII: DOI: Reference:
S0301-2115(17)30162-8 http://dx.doi.org/doi:10.1016/j.ejogrb.2017.04.010 EURO 9853
To appear in:
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Received date: Revised date: Accepted date:
11-3-2016 14-3-2017 4-4-2017
Please cite this article as: Le Quoc V, Abhari Sina, Abuzeid Omar M, DeAnna Jennifer, Satti Mohamed A, Abozaid Tarek, Khan Iqbal, Abuzeid Mostafa I.Modified natural cycle for embryo transfer using frozen-thawed blastocysts: a satisfactory option.European Journal of Obstetrics and Gynecology and Reproductive Biology http://dx.doi.org/10.1016/j.ejogrb.2017.04.010 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Modified natural cycle for embryo transfer using frozen-thawed blastocysts: a satisfactory option Quoc V. Le, MD1, Sina Abhari, MD2, Omar M. Abuzeid, MD2, Jennifer DeAnna DO3, Mohamed A. Satti, MD2, Tarek Abozaid, BS,ELD/TS (ABB)4, Iqbal Khan PhD 4, Mostafa I. Abuzeid, MD2, 4, 5
1
Michigan State University College of Human Medicine, East Lansing, MI, USA Department of Obstetrics and Gynecology, Hurley Medical Center/ Michigan State University college of Human Medicine (Flint Campus), Flint, MI, USA 3 Department of Obstetrics and Gynecology, Genesys Regional Medical Center, Grand Blanc, MI, USA 4 IVF Michigan Rochester Hills and Flint PC, MI, USA 5 Division of Reproductive Endocrinology and Infertility, Hurley Medical Center/Michigan State University college of Human Medicine (Flint Campus), Flint, MI, USA 2
Corresponding author information: Quoc V Le, MD 231 Albert Sabin Way ML 0526 Cincinnati, OH 45267-0526 Phone: +15863037594 Fax: +15135583558 Email: [email protected]
CONDENSATION: Study describing pregnancy outcomes in modified natural and down-regulated hormonally controlled frozen embryo transfer cycles using frozen-thawed blastocysts concludes that both protocols have comparable successful outcomes.
Objective: To describe pregnancy outcomes of frozen-thawed blastocysts cycles using modified natural cycle frozen embryo transfers (NC-FET) and down-regulated hormonally controlled frozen embryo transfers (HC-FET) protocols. Study Design: This retrospective cohort study included all patients undergoing either modified NC-FET or down-regulated HC-FET using frozen-thawed day 5 embryos. Cycles with donor blastocysts were excluded. Four hundred twenty eight patients underwent a total of 493 FET
cycles. Patients with regular menses and evidence of ovulation underwent modified NC-FET. These patients were given hCG 10,000 IU IM on the day of LH-surge. Vaginal progesterone (P4) was started two days later and blastocyst transfer was planned seven days after detecting the LH surge. Anovulatory patients and some ovulatory patients underwent down-regulated HC-FET. These patients were placed on medroxy-progesterone acetate (10mg) for 10 days to bring on menses and were also given a half-dose of GnRH-agonist (GnRH-a) on the third day of medroxy-progesterone acetate. Exogenous estradiol was initiated on the third day of menses. Once serum E2 levels reached >500 pg/mL and endometrial lining reached >8mm, intramuscular (IM) P4 in oil was administered. Blastocyst FET was planned 6 days after initiating P4. The primary outcomes included clinical pregnancy and delivery rates. Results: There were 197 patients in the modified NC-FET protocol and 181 in the downregulated HC-FET protocol. Mean age (years), day-3 FSH levels (mIU/mL) and percentage of patients with male factor infertility were significantly higher and mean BMI (kg/m2) was significantly lower in modified NC-FET compared to HC-FET, respectively. Analysis of the first cycle pregnancy outcomes revealed no significant differences in clinical pregnancy rate (54.3% vs. 52.5%) and delivery rate (47.2% vs. 43.6%) between modified NC-FET and HC-FET. Logistic regression analysis showed age (OR=0.939, 95% CI 0.894–0.989, p=0.011), number of blastocysts transferred (OR=1.414, 95% CI 1.046-1.909, p=0.024), and the year of FET (OR=1.127, 95% CI 1.029-1.234, p=0.010) were significant factors impacting clinical pregnancy. An age analysis within three age groups (≤35, 36-39, ≥40) was performed, but no significant difference in clinical pregnancy was observed. Conclusion: Our data suggests that modified NC-FET protocol has comparable pregnancy outcomes to down-regulated HC-FET when utilizing frozen-thawed day 5 embryos. Keywords: natural cycle, frozen-thawed embryo transfer, hormonally controlled cycles, blastocysts
INTRODUCTION: The use of frozen embryo transfers (FET) has gained momentum mostly as a result of the increase in the success rate over the past decade. [1] There are many advantages of cryopreservation of embryos after in vitro fertilization. By freezing excess viable embryos after a fresh cycle, less ovarian stimulation cycles are required, and as a result, this approach minimizes the risk of iatrogenic complications such as ovarian hyperstimulation syndrome and reduces the cost associated with fresh cycles. [2] FET is a safe and cost-effective way to increase the cumulative pregnancy rate per oocyte recovery. Most FET cycles are performed in hormonally controlled (HC-FET) cycles. This is a more convenient protocol for both patients and infertility centers because one can control the timing of embryo transfer. [2] Endometrial preparation is achieved through estradiol (E2) and progesterone (P4) supplementation during the FET cycle. Furthermore, precise synchronization of endometrial growth and the developing embryos was achieved using GnRH agonist (GnRH-a) for pituitary suppression. [2] The natural cycle protocol (NC-FET) is another popular protocol. The main advantage of the natural cycle protocol is that it requires little or no exogenous hormones; therefore, cost for frozen-thawed embryo transfer is minimized. In a modified version
of the natural cycle protocol, human chorionic gonadotropin (hCG) is administered to induce ovulation when the dominant follicle is of adequate size on ultrasound. By inducing ovulation with hCG, the need to monitor the LH level is eliminated. [3] More recently during NC-FET, Kim et al. (2014) have shown that luteal phase support with progesterone supplementation decreased miscarriage rate and improved live birth rate. [4] There are a number of studies comparing NC-FET and HC-FET with conflicting results. Some studies have shown that pregnancy outcomes were comparable between down-regulated HC-FET and true NC-FET. [2,5] Kawamura et al. (2007) compared true NC-FET versus HCFET and reported comparable outcomes. [6] However, a study done by Morozov et al. (2007) showed that true NC-FET had better outcomes than HC-FET. [7] Chang et al. (2011) also demonstrated better results with NC-FET, both true and modified protocols, when compared to HC-FET. [8] However, a recent report suggested that down-regulated HC-FET cycles have higher live-birth rate than true NC-FET for frozen-thawed blastocyst-stage embryos. [9] The aim of this study is to describe the pregnancy outcomes of frozen thawed blastocyst cycles using modified NC-FET and HC-FET protocols.
MATERIALS AND METHOD: This retrospective cohort study included 428 patients who underwent 493 cycles using frozenthawed day 5 embryos between 2006 and 2014. This study received an exemption from Local Institutional Review Board. Only patients who have attempted blastocyst transfers from cryopreserved day 5 embyros (e.g. morulas, early blastocysts and blastocysts) were included in this study. Cryopreserved zygotes and day-3 embryos that subsequently matured to blastocysts stage prior to transfer and donor blastocysts were not included in our study. The decision for patients to undergo either natural or medicated cycle was determined after considering the patient’s ovulatory status and menstrual cycle regularity. Patients who had regular menstrual cycles were eligible to undergo the modified NC-FET protocol. Patients who had irregular menstrual cycles and diagnosed with ovulatory disorder were recommended to undergo the down-regulated HC-FET protocol. The protocols for modified NC-FET and down-regulated HCFET cycles were unchanged over the course of the study. Blastocyst grading was previously described by Gardner et al. (2000) with high-grade blastocysts considered as a grade 3AA or above. [10] Vitrification and Thawing Technique: In our clinic, we adopted vitrification since 2006 as the sole cryopreservation method to freeze day 5 embryos. We used a 5-step thaw protocol. Detailed vitrification and thaw method has been described previously. [11] Modified NC-FET Patients underwent 2-3 trans-vaginal ultrasound scans (TVUS) with measurement of serum estradiol and progesterone levels, as well as the endometrial thickness during follicular phase until day of LH-surge. The LH surge was defined as a 2.5-fold increase above the mean of the previous measurements. The patients then received either 10,000 units of urinary hCG, intramuscular or 250μg of recombinant hCG subcutaneous to supplement the LH surge. Vaginal progesterone supplementation (Crinone 8% Vaginal Gel, Watson Pharmaceuticals, Morristown, NJ, USA) was started 2-days after the LH surge. Subsequently, embryo transfer was performed 7
days after the LH-surge. If pregnancy was successful, the patient continued on progesterone supplementation until 8 weeks gestation. Down–regulated HC-FET Patients were placed on 10-days of medroxy-progesterone acetate (Provera 10mg) to bring on a menstrual period prior to the FET cycle. A half dose of long-acting GnRH-a IM (Lupron depot 3.75mg, Abbvie INC. Chicago, IL) was administered on the third day of the Provera course. On the third day of menses, the patients were started on both oral estradiol (Estrace 2 mg, Warner Chilcott LLC, Rockaway, NJ, USA) three times daily and E2 patches (Vivelle-Dot 0.1mg, Novartis Pharmaceuticals, Basel, Switzerland) on every fourth day. Once endometrial thickness was >8 mm and serum estradiol was >500 pg/ml, patients were started on progesterone (P4) in oil 50 mg IM for the first day, followed by 100mg daily thereafter. Embryo transfer was performed 6 days after initiating P4 treatment. Both E2 and P4 were continued until 9 weeks of gestation if pregnancy test was positive. Embryo Transfer & Post-transfer workup Frozen blastocysts were thawed on the day of embryo transfer, while morula and early blastocysts were thawed the day prior. Only viable, good quality blastocysts were transferred. Any blastocyst that had a C quality for the inner cell mass or the trophectoderm were not transferred. The transfers were performed by the senior author (M.I.A) using the same technique under ultrasound guidance. An hCG level was measured 12 days after the FET. If the pregnancy test was positive, TVUS was performed two weeks later to determine the number of gestational sacs and fetal viability. A clinical pregnancy was defined by the presence of an intrauterine gestational sac. Birth outcome data were collected from the patients.
Statistical Analysis Statistical analysis was performed using SPSS 22.0 (IBM, Armonk, New York, USA). Independent t-test, chi-square analysis, and binary log regression analysis were used where appropriate. RESULTS: A total of 428 patients were included in this study. There were 226 patients in the modified NCFET group and 202 patients in the HC-FET group. (Figure 1) There were 63 patients (31.2%) with regular ovulatory cycles that opted to undergo the down-regulated HC-FET protocol. Twenty-nine patients in modified NC-FET and 21 patients in the HC-FET protocol were canceled due to failure in the thaw process or blastocysts degenerating prior to transfer. The remaining 197 patients in modified NC-FET protocol and 181 patients in HC-FET protocol underwent a total 225 and 218 FET cycles, respectively. There were 187 patients in the modified NC-FET and 175 in HC-FET protocol who underwent cumulative per patient analysis. Ten patients in modified NC-FET protocol and 6 patients in HC-FET protocol were excluded from cumulative per patient analysis as they switched protocols in subsequent cycles (mixed cycles). There were no significant differences between the two groups in clinical pregnancy rate from prior fresh cycle transfers and in the percentage of patients who underwent freeze-all after fresh cycle (data not provided). In addition, there were no significant differences between the two
groups in percentage of the various grades of the fresh blastocysts, early blastocysts or morulas (data not provided). Mean age, day-3 FSH, and percentage of patients with male factor infertility were significantly higher in NC-FET compared to HC-FET. Mean BMI was significantly lower in the NC-FET group. (Table I) For cycle characteristics, there were a significantly higher number of blastocysts transferred per cycle in the HC-FET group. (Table II) There were no significant differences in implantation rate (40.5% vs. 36.9%), chemical pregnancy rate (60.9% vs. 60.8%), clinical pregnancy rate (54.3% vs. 52.5%), or delivery rates (47.2% vs. 43.6%) between the modified NC-FET group and down-regulated HC FET group, respectively. (Table III) There were also no differences in pregnancy outcomes when comparing the two groups by cumulative pregnancy per patient. (Table IV) Subgroup analysis comparing pregnancy outcomes between patients who were ovulatory with regular cycles who underwent modified NC-FET protocol to those who underwent HC-FET protocol revealed no differences in clinical pregnancy for the first cycle (data not provided). A binary logistic regression analysis was performed to find a correlation between the baseline characteristics and pregnancy outcomes. (TABLE V) Age, number blastocyst transferred and year of FET were factors significantly impacting clinical pregnancy rate. We stratified the data into age groups to account for this bias. (TABLE VI) There were no significant differences in clinical pregnancy rate when comparing modified NC-FET and down-regulated HC-FET groups in patients≤35, between 36-39, and ≥40 years old. COMMENTS: Frozen embryo transfer has become a widely accepted practice in assisted reproductive technology, yet determining the optimal cryopreservation method and endometrial preparation protocols has been difficult. Recent evidence has shown that in cryopreserved cycles, blastocysts have improved outcomes compared with cleavage stage embryos. [12,13,14] More recent cryopreservation techniques have demonstrated more rapid freezing ability, improved post-thaw survival, and have not been associated with any increased adverse embryonic or obstetrical outcomes. [1,15] Our data suggests that there were no differences in clinical pregnancy, delivery, miscarriage and multiple pregnancy rates per transfer between the two protocols. Such findings remain the same after a subgroup analysis comparing pregnancy outcomes in patients with ovulatory cycles in the two protocols. Our findings support the notion that modified NC-FET protocol described in our study is as effective as down-regulated HC-FET, albeit is simpler and more tolerable by the patients. Therefore, we believe it should be the protocol of choice in patients who have regular and ovulatory cycles. In a traditional natural cycle protocol, endogenous LH level is measured throughout the cycle until levels reach above the LH-surge threshold before the embryo was transferred. [3] The modified NC-FET protocol differs from the traditional natural cycle protocol in that hCG is given to patients to trigger oocyte maturation and ovulation when follicular maturation and endometrial thickness reached a certain threshold without needing to measure the LH-surge. [4,8,16] There were variations in our modified NC-FET protocol compared to those in prior
studies. In our study, hCG was administered once LH-surge was confirmed by serum measurements as a supplement to the LH-surge. In a study by Weissman et al. (2011), hCG was not administered if a significant LH rise was observed. [17] The author suggested that this methodology could compromise the accuracy of timing frozen-thawed embryo transfer. We did not observe any detrimental effects when administering hCG after the LH-surge and achieved highly acceptable pregnancy outcomes. Though many patients prefer the NC-FET protocol because it does not require exogenous hormones to prime the endometrium, there are some known disadvantages. Because the accurate timing of ovulation is crucial for these patients undergoing the natural cycle protocol, more frequent visits are often needed to assess the endometrium. This is more difficult, especially when patients have some variability in their cycles. For this reason, the risk of cycle cancelation is potentially high. [18] However, the use of an hCG trigger for NC-FET can decrease the number of visits while aiding in estimation of implantation window without deleteriously effecting delivery rates. [17] On the other hand, we believe that less monitoring may lead to early administration of hCG when, in fact, the follicle size and function may not be optimal for its action. Ultimately, this may lead to an element of luteal phase insufficiency that may affect pregnancy outcome. Data by Kim et al. (2014) has shown that luteal phase support (LPS) with progesterone in NC-FET yields improved outcomes. [4] While their data did not show differences in pregnancy, implantation and multiple pregnancy rates between women who received LPS and those who did not, there was a significant decrease in miscarriage rate and a significant increase in live birth rate in women who received progesterone. The need for LPS is likely secondary to the fact that infertile women undergoing FET likely have suboptimal progesterone. [4] While the need for progesterone administration is highlighted, the most efficacious route of progesterone administration in HC-FET still needs to be determined. There are varying data in regards to the route of progesterone administration in HC-FET. Serum progesterone levels are shown to be higher with IM administration. [19] Pritts et al. (2002) found that IM progesterone was superior to vaginal administration. [20] However, some suggest that vaginal progesterone still provides comparable outcomes to intramuscular progesterone. [21] To our knowledge, the current study is the only one describing pregnancy outcomes in modified NC-FET and down-regulated HC-FET cycles using frozen-thawed blastocysts. In a meta-analysis by Groenewoud et al. (2013), the author stated that based on current literature, it is not possible to identify one method of endometrium preparation in FET more superior over the others. [3] However, the author did not analyze studies comparing modified NC-FET and downregulated HC-FET. Other studies concluded that natural endometrial preparation yielded better outcome in comparison to exogenous hormonal cycles. [6,22] Patients with normal ovarian function may achieve the best results using natural rather than hormonally manipulated cycles because exogenous estrogen may alter the physiologic concentration of endogenous hormone, resulting in negative effects on the endometrium. [7,23] When outcomes are similar between the two protocols, clinical decision should be based on cost and convenience for the patient. There are several reasons to suggest hormonally controlled cycles for patients undergoing frozen embryo transfers. First, HC-FET is necessary for most patients with irregular or absent menstrual cycles. A hormonally controlled cycle ensures an orderly maturation of the endometrium, which is critical for embryo implantation. Second, infertility specialists prefer this method because they have more control over the timing of the transfer. [3] Furthermore, patients require less office
visits to assess endometrial thickness and hormone levels compared to patients undergoing natural cycle FET. Despite all the advantages of HC-FET, it should be addressed that it introduces exogenous hormones to the patient. These medications are costly, providing a higher financial burden on patients, a burden that many are unable to surmount. If patients were able to successfully undergo NC- FET, then these burdens associated with HC-FET would be avoided. Therefore, the patient should be given the option of NC-FET in order to maintain autonomy through choice of cycle approach. Our study has a few limitations. The current study is retrospective in nature with the inherent biases associated with the study design. We acknowledge that, the comparison between the two groups in our study is limited because the two treatment groups are not comparable since patients in group 1 are ovulatory, while the majority of patients in group 2 have ovulatory disturbances. With that in mind, a subgroup analysis performed to account for this bias. Although we were not able to control for certain baseline characteristics, a multivariate log regression analysis showed age being the only significant factor impacting clinical pregnancy in our study. Large prospective, randomized trials should be conducted to confirm our findings.
ACKNOWLEDGEMENT: The authors would like to thank the staff at IVF Michigan for helping with data collection and Jenny LaChance from the Research Department at Hurley’s Medical Center for performing the statistical analysis. CONFLICT OF INTEREST: The authors in this study have no conflicts of interest to disclose.
REFERENCES: [1] Wong KM, Mastenbroek S, Repping S. Cryopreservation of human embryos and its contribution to in vitro fertilization success rate. Fertil Steril 2014; 102(1):19-26. [2] Gelabaya TA, Nardo LG, Hunter HR et al. Cryopreserved-thawed ET in natural or down regulated hormonally controlled cycles: a retrospective study. Fertil Steril 2006; 85(3):603-9. [3] Groenewoud ER, Cantineau AE, Kollen BJ et al. What is the optimal means of preparing the endometrium in frozen-thawed embryo transfer cycles? A systematic review and metaanalysis. Hum Reprod Update 2013; 19(5):458-70. [4] Kim CH, Lee YJ, Lee KH, et al. The effect of luteal phase progesterone supplementation on natural frozen-thawed embryo transfer cycles. Obstet Gynecol Sci 2014; 57(4):291-296. [5] Spandorfer SD, Fasouliotis S, Cimmino C et al. Blastocyst frozen embryo transfer (FET): comparison of outcome with replacement in natural or programmed/medicated cycle. Fertil Steril 2004; 82,S154. [6] Kawamura T, Hiroshi M, Atsushi Y et al. Clinical outcome of two different endometrial preparation methods for cryopreserved thawed embryo transfer in patients with a normal menstrual cycle. Reprod Med and Biol 2007; (6)1. [7] Morozov V, Ruman J, Kenigsberg D et al. Natural cycle cryo-thaw transfer may improve pregnancy outcome. J Assist Reprod and Genetics 2007; 24:119-123. [8] Chang EM, Han JE, Kim YS et al. Use of the natural cycle and verification thawed blastocyst transfer results in better in-vitro fertilization outcomes: cycle regimens of verification thawed blastocyst transfer. J Assist Reprod Genet 2011; 28:369-74. [9] Hill MJ, Miller KA, Fatarelli JL. A GnRH-agonist and exogenous hormone stimulation protocol has a higher live-birth rate than a natural endogenous hormone protocol for frozenthawed blastocyst-stage embryo transfer cycles: an analysis of 1391 cycles. Fertil Steril 2010; 93(2):416-22. [10] Gardner DK, Lane M, Stevens J, et al. Blastocyst score affects implantation and pregnancy outcome: towards a single blastocyst transfer. Fertil Steril 2000; 73(6):1155-58. [11] Khan I, Urich M, Abozaid T, et al. P-169 Blastocysts vitrified at room temperature can be thawed at 37 C: a retrospective study. Human Reprod, 2012; 27(Suppl 2). [12] Fernandez-Shaw, S., Cercas R, Brana C, et al. Ongoing and cumulative pregnancy rate after cleavage-stage versus blastocyst-stage embryo transfer using vitrification for cryopreservation: impact of age on the results. J Assist Reprod Genet. 2015; 32(2):177-84. [13] Surrey E., Keller J., Stevens J. Freeze-all: enhanced outcomes with cryopreservation at the blastocyst stage versus pronuclear stage using slow-freeze techniques. Reprod. Biomed. Online 2010; 21:411-17. [14] Anderson A., Weikert M., Crain J. Determining the most optimal stage for embryo cryopreservation. Reprod. Biomed. Online 2004; 8(2):207-11. [15] Roque, M., Freeze-all policy: is it time for that? J Assist Reprod Genet. 2015; 32(2):171-6. [16] Fatemi HM, Krou D, Borgain C et al. Cryopreserved-thawed human embryo transfer: spontaneous natural cycle is superior to human chorionic gonadotropin-induced natural cycles. Fertil Steril 2010; 94(6):2054-58. [17] Weissman A, Horowitz E, Ravhon A et al. Spontaneous ovulation versus HCG triggering for timing natural-cycle frozen-thawed embryo transfer: a randomized study. Reprod Biomed Online 2011; 23:484-89. [18] Dal Prato L, Borini A, Cattoli M et al. Endometrial preparation for frozen-thawed embryo
transfer with or without pretreatment with gonadotropin-releasing hormone agonist. Fertil Steril 2002; 77(5):956-60. [19] ASRM Practice Committee. Progesterone supplementation during the luteal phase in early pregnancy in the treatment of infertility: an educational bulletin. Fertil Stertil. 2008; 90:S1503. [20] Pritts, E., Atwood, A. Luteal phase support in infertility treatment: A meta-analysis of the randomized trials. Human Reprod. 2002. 17(9):2287-99. [21] Berger, BJ, Philips JA. Pregnancy outcomes in oocyte donation recipients: vaginal gel versus intramuscular injection progesterone replacement. Assist Reprod Genet. 2012; 29(3): 237–242. [22] Levron J, Yerushalmi GM, Brengauz M et al. Comparison between two protocols for thawed-embryo transfer: natural cycle versus exogenous hormone replacement. Gynecol Endocrinol 2014; 30(7):494-7. [23] Creus M, Ordi J, Fbregues F et al. The effect of different hormone therapies on integrin expression and pinopode formation in the human endometrium: a controlled study. Hum Reprod 2003; 18:683–93.
Figure 1: Flow Chart of the Population of the Study
428 Patients (493 Cycles)
Modified NC-FET (226 patients)
Down-reg. HC-FET
(202 patients)
Canceled
Canceled (29 patients)*
(21 patients)
197 patients (225 cycles)
187 patients Cumulative analysis
*
10 patients Excluded Mixed method**
*
181 patients (218 cycles)
175 patients Cumulative analysis
6 patients Excluded Mixed methods**
There is no difference in proportion of canceled cycles by patient. The cancelation rate was 12.8% in modified NCFET group vs.10.4% in the down-regulated HC-FET group (p=0.434) ** For cumulative analysis per group, patients that have undergone mixed methods in subsequent cycles were excluded from analysis
Table I: Baseline characteristics of the first cycle of patients in both groups Mod. NC-FET Down-reg. HC-FET (n=197) (n=181) a Mean Age (y) 34.3 ± 4.2 33.3 ± 4.8 2 a Mean BMI (kg/m ) 25.3 ± 5.5 27.7 ± 7.0 a Mean Basal FSH (mIU/mL) 6.6 ± 1.9 6.0 ± 3.3 Duration of infertility (y) a 3.3 ± 2.7 3.1 ± 2.6 Primary Infertility b 118 (59.9%) 122 (67.4%) Causes of Infertility Male factor b 139 (66.0%) 97 (53.6%) b Tubal factor 54 (27.4%) 52 (28.7%) b Ovulatory 0 (0.0%) 118 (65.2%)c Endometriosis b 54 (27.4%) 40 (22.1%) b Uterine 69 (35.0%) 58 (32.0%)
p-value 0.04 0.00 0.014 0.57 0.13 0.014 0.78 0.00 0.23 0.54
a
Values reported as mean ± SD Values reported as number of patients with percentage in parentheses c Sixty three patients (31.2%) with regular menstrual cycles elected to undergo modified HC-FET cycle b
Table II: Cycle characteristics of the first cycle of patients in both groups Mod. NC-FET Down-reg. HC(n=197) FET (n=181) Mean endometrial thickness (mm) a 9.6 ± 2.0 9.7 ± 2.1 a No. Blast. transferred/cycle 1.9 ± 0.7 2.1 ± 0.7 Cycles with High Grade Blast.b 66 (33.5%) 67 (37.0%) a b
Values reported as mean ± SD Value reported as number of patients with percentage in parentheses
Table III: Pregnancy Outcomes of the first cycle of patients in both groups Mod. NC-FET Down-reg. HC-FET (n=197) (n=181) Implantation Rate a 40.5% 36.4% b No. Chemical Pregnancy 120 (60.9%) 110 (60.8%) b No. Clinical Pregnancy 107 (54.3%) 95 (52.5%) b No. Delivery Pregnancy 93 (47.2%) 79 (43.6%) b No. Miscarriage 14 (13.1%) 16 (16.8%) b No. Ectopic Pregnancy 0 (0%) 2 (2.1%) No. Multiple Pregnancies b 25 (23.4%) 29 (30.5%) a b
p-value 0.69 0.006 0.48
Implantation rate is the number of sacs visualized Value reported as number of patients with percentage in parentheses
p-value 0.28 0.98 0.72 0.49 0.98 0.13 0.25
Table IV: Cumulative Pregnancy Outcomes Per Patient In Both Groups Mod. NC-FET Down-reg. HC-FET (n=187) (n=175) a No. Chemical Pregnancy 122 (65.2%) 112 (64.0%) a No. Clinical Pregnancy 111 (59.4%) 97 (55.4%) a No. Delivery Pregnancy 96 (51.3%) 82 (46.9%) No. Miscarriage a 15 (13.5%) 15 (15.4%) No. Ectopic Pregnancy a 0 (0%) 2 (2.1%) No. Multiple Pregnancies a 27 (24.3%) 30 (30.9%)
p-value 0.81 0.45 0.39 0.65 0.13 0.29
a
Data presented as number of patients followed by percentage in parentheses Cumulative pregnancy per patient includes the cycle with the best available pregnancy outcome for each patient (ie. if patient has undergone two cycles and had no chemical pregnancy after the first FET and a clinical pregnancy in the second, we only included the pregnancy data from the cycle where patient had the clinical pregnancy)
Table V: Multivariate logistic regression with clinical pregnancy as dependent variable Clinical Pregnancy OR (95% CI) p-value Age (years) a 0.939 (0.894 - 0.989) 0.011 2 a BMI (kg/m ) 0.98 (0.95 – 1.01) 0.25 Endometriosis (yes/no) a 0.90 (0.80 – 1.02) 0.09 a Basal FSH (mIU/mL) 1.02 (0.94 – 1.11) 0.62 Cycle Type (NC/HC) a 0.92 (0.59 – 1.44) 0.72 a No. Blast. transferred (#) 1.414 (1.046 – 1.909) 0.024 Year of FET (year) a 1.127 (1.029 – 1.234) 0.010 Data is presented as odds ratio with the 95% confidence interval in parentheses
Table VI: Age range Analysis with clinical pregnancy as dependent variable during the first cycle for each patient Clinical Pregnancy Mod. NC-FET Down-reg. HC-FET p-value ≤ 35 yrs n=93 a n=112 0.72 53 (57.0%) b 61 (54.5%) 36-39 yrs n=36 n=23 0.06 13 (36.1%) 14 (60.9%) ≥40 yrs n=15 n=15 0.46 5 (33.3%) 7(46.7%) a b
The number of patients in each group that meet a fall into a certain age range are reported on this table Numbers reported as number of patient with positive clinical pregnancy and percentage of patients in pregnancy
S0301-2115(17)30162-8 http://dx.doi.org/doi:10.1016/j.ejogrb.2017.04.010 EURO 9853
To appear in:
EURO
Received date: Revised date: Accepted date:
11-3-2016 14-3-2017 4-4-2017
Please cite this article as: Le Quoc V, Abhari Sina, Abuzeid Omar M, DeAnna Jennifer, Satti Mohamed A, Abozaid Tarek, Khan Iqbal, Abuzeid Mostafa I.Modified natural cycle for embryo transfer using frozen-thawed blastocysts: a satisfactory option.European Journal of Obstetrics and Gynecology and Reproductive Biology http://dx.doi.org/10.1016/j.ejogrb.2017.04.010 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Modified natural cycle for embryo transfer using frozen-thawed blastocysts: a satisfactory option Quoc V. Le, MD1, Sina Abhari, MD2, Omar M. Abuzeid, MD2, Jennifer DeAnna DO3, Mohamed A. Satti, MD2, Tarek Abozaid, BS,ELD/TS (ABB)4, Iqbal Khan PhD 4, Mostafa I. Abuzeid, MD2, 4, 5
1
Michigan State University College of Human Medicine, East Lansing, MI, USA Department of Obstetrics and Gynecology, Hurley Medical Center/ Michigan State University college of Human Medicine (Flint Campus), Flint, MI, USA 3 Department of Obstetrics and Gynecology, Genesys Regional Medical Center, Grand Blanc, MI, USA 4 IVF Michigan Rochester Hills and Flint PC, MI, USA 5 Division of Reproductive Endocrinology and Infertility, Hurley Medical Center/Michigan State University college of Human Medicine (Flint Campus), Flint, MI, USA 2
Corresponding author information: Quoc V Le, MD 231 Albert Sabin Way ML 0526 Cincinnati, OH 45267-0526 Phone: +15863037594 Fax: +15135583558 Email: [email protected]
CONDENSATION: Study describing pregnancy outcomes in modified natural and down-regulated hormonally controlled frozen embryo transfer cycles using frozen-thawed blastocysts concludes that both protocols have comparable successful outcomes.
Objective: To describe pregnancy outcomes of frozen-thawed blastocysts cycles using modified natural cycle frozen embryo transfers (NC-FET) and down-regulated hormonally controlled frozen embryo transfers (HC-FET) protocols. Study Design: This retrospective cohort study included all patients undergoing either modified NC-FET or down-regulated HC-FET using frozen-thawed day 5 embryos. Cycles with donor blastocysts were excluded. Four hundred twenty eight patients underwent a total of 493 FET
cycles. Patients with regular menses and evidence of ovulation underwent modified NC-FET. These patients were given hCG 10,000 IU IM on the day of LH-surge. Vaginal progesterone (P4) was started two days later and blastocyst transfer was planned seven days after detecting the LH surge. Anovulatory patients and some ovulatory patients underwent down-regulated HC-FET. These patients were placed on medroxy-progesterone acetate (10mg) for 10 days to bring on menses and were also given a half-dose of GnRH-agonist (GnRH-a) on the third day of medroxy-progesterone acetate. Exogenous estradiol was initiated on the third day of menses. Once serum E2 levels reached >500 pg/mL and endometrial lining reached >8mm, intramuscular (IM) P4 in oil was administered. Blastocyst FET was planned 6 days after initiating P4. The primary outcomes included clinical pregnancy and delivery rates. Results: There were 197 patients in the modified NC-FET protocol and 181 in the downregulated HC-FET protocol. Mean age (years), day-3 FSH levels (mIU/mL) and percentage of patients with male factor infertility were significantly higher and mean BMI (kg/m2) was significantly lower in modified NC-FET compared to HC-FET, respectively. Analysis of the first cycle pregnancy outcomes revealed no significant differences in clinical pregnancy rate (54.3% vs. 52.5%) and delivery rate (47.2% vs. 43.6%) between modified NC-FET and HC-FET. Logistic regression analysis showed age (OR=0.939, 95% CI 0.894–0.989, p=0.011), number of blastocysts transferred (OR=1.414, 95% CI 1.046-1.909, p=0.024), and the year of FET (OR=1.127, 95% CI 1.029-1.234, p=0.010) were significant factors impacting clinical pregnancy. An age analysis within three age groups (≤35, 36-39, ≥40) was performed, but no significant difference in clinical pregnancy was observed. Conclusion: Our data suggests that modified NC-FET protocol has comparable pregnancy outcomes to down-regulated HC-FET when utilizing frozen-thawed day 5 embryos. Keywords: natural cycle, frozen-thawed embryo transfer, hormonally controlled cycles, blastocysts
INTRODUCTION: The use of frozen embryo transfers (FET) has gained momentum mostly as a result of the increase in the success rate over the past decade. [1] There are many advantages of cryopreservation of embryos after in vitro fertilization. By freezing excess viable embryos after a fresh cycle, less ovarian stimulation cycles are required, and as a result, this approach minimizes the risk of iatrogenic complications such as ovarian hyperstimulation syndrome and reduces the cost associated with fresh cycles. [2] FET is a safe and cost-effective way to increase the cumulative pregnancy rate per oocyte recovery. Most FET cycles are performed in hormonally controlled (HC-FET) cycles. This is a more convenient protocol for both patients and infertility centers because one can control the timing of embryo transfer. [2] Endometrial preparation is achieved through estradiol (E2) and progesterone (P4) supplementation during the FET cycle. Furthermore, precise synchronization of endometrial growth and the developing embryos was achieved using GnRH agonist (GnRH-a) for pituitary suppression. [2] The natural cycle protocol (NC-FET) is another popular protocol. The main advantage of the natural cycle protocol is that it requires little or no exogenous hormones; therefore, cost for frozen-thawed embryo transfer is minimized. In a modified version
of the natural cycle protocol, human chorionic gonadotropin (hCG) is administered to induce ovulation when the dominant follicle is of adequate size on ultrasound. By inducing ovulation with hCG, the need to monitor the LH level is eliminated. [3] More recently during NC-FET, Kim et al. (2014) have shown that luteal phase support with progesterone supplementation decreased miscarriage rate and improved live birth rate. [4] There are a number of studies comparing NC-FET and HC-FET with conflicting results. Some studies have shown that pregnancy outcomes were comparable between down-regulated HC-FET and true NC-FET. [2,5] Kawamura et al. (2007) compared true NC-FET versus HCFET and reported comparable outcomes. [6] However, a study done by Morozov et al. (2007) showed that true NC-FET had better outcomes than HC-FET. [7] Chang et al. (2011) also demonstrated better results with NC-FET, both true and modified protocols, when compared to HC-FET. [8] However, a recent report suggested that down-regulated HC-FET cycles have higher live-birth rate than true NC-FET for frozen-thawed blastocyst-stage embryos. [9] The aim of this study is to describe the pregnancy outcomes of frozen thawed blastocyst cycles using modified NC-FET and HC-FET protocols.
MATERIALS AND METHOD: This retrospective cohort study included 428 patients who underwent 493 cycles using frozenthawed day 5 embryos between 2006 and 2014. This study received an exemption from Local Institutional Review Board. Only patients who have attempted blastocyst transfers from cryopreserved day 5 embyros (e.g. morulas, early blastocysts and blastocysts) were included in this study. Cryopreserved zygotes and day-3 embryos that subsequently matured to blastocysts stage prior to transfer and donor blastocysts were not included in our study. The decision for patients to undergo either natural or medicated cycle was determined after considering the patient’s ovulatory status and menstrual cycle regularity. Patients who had regular menstrual cycles were eligible to undergo the modified NC-FET protocol. Patients who had irregular menstrual cycles and diagnosed with ovulatory disorder were recommended to undergo the down-regulated HC-FET protocol. The protocols for modified NC-FET and down-regulated HCFET cycles were unchanged over the course of the study. Blastocyst grading was previously described by Gardner et al. (2000) with high-grade blastocysts considered as a grade 3AA or above. [10] Vitrification and Thawing Technique: In our clinic, we adopted vitrification since 2006 as the sole cryopreservation method to freeze day 5 embryos. We used a 5-step thaw protocol. Detailed vitrification and thaw method has been described previously. [11] Modified NC-FET Patients underwent 2-3 trans-vaginal ultrasound scans (TVUS) with measurement of serum estradiol and progesterone levels, as well as the endometrial thickness during follicular phase until day of LH-surge. The LH surge was defined as a 2.5-fold increase above the mean of the previous measurements. The patients then received either 10,000 units of urinary hCG, intramuscular or 250μg of recombinant hCG subcutaneous to supplement the LH surge. Vaginal progesterone supplementation (Crinone 8% Vaginal Gel, Watson Pharmaceuticals, Morristown, NJ, USA) was started 2-days after the LH surge. Subsequently, embryo transfer was performed 7
days after the LH-surge. If pregnancy was successful, the patient continued on progesterone supplementation until 8 weeks gestation. Down–regulated HC-FET Patients were placed on 10-days of medroxy-progesterone acetate (Provera 10mg) to bring on a menstrual period prior to the FET cycle. A half dose of long-acting GnRH-a IM (Lupron depot 3.75mg, Abbvie INC. Chicago, IL) was administered on the third day of the Provera course. On the third day of menses, the patients were started on both oral estradiol (Estrace 2 mg, Warner Chilcott LLC, Rockaway, NJ, USA) three times daily and E2 patches (Vivelle-Dot 0.1mg, Novartis Pharmaceuticals, Basel, Switzerland) on every fourth day. Once endometrial thickness was >8 mm and serum estradiol was >500 pg/ml, patients were started on progesterone (P4) in oil 50 mg IM for the first day, followed by 100mg daily thereafter. Embryo transfer was performed 6 days after initiating P4 treatment. Both E2 and P4 were continued until 9 weeks of gestation if pregnancy test was positive. Embryo Transfer & Post-transfer workup Frozen blastocysts were thawed on the day of embryo transfer, while morula and early blastocysts were thawed the day prior. Only viable, good quality blastocysts were transferred. Any blastocyst that had a C quality for the inner cell mass or the trophectoderm were not transferred. The transfers were performed by the senior author (M.I.A) using the same technique under ultrasound guidance. An hCG level was measured 12 days after the FET. If the pregnancy test was positive, TVUS was performed two weeks later to determine the number of gestational sacs and fetal viability. A clinical pregnancy was defined by the presence of an intrauterine gestational sac. Birth outcome data were collected from the patients.
Statistical Analysis Statistical analysis was performed using SPSS 22.0 (IBM, Armonk, New York, USA). Independent t-test, chi-square analysis, and binary log regression analysis were used where appropriate. RESULTS: A total of 428 patients were included in this study. There were 226 patients in the modified NCFET group and 202 patients in the HC-FET group. (Figure 1) There were 63 patients (31.2%) with regular ovulatory cycles that opted to undergo the down-regulated HC-FET protocol. Twenty-nine patients in modified NC-FET and 21 patients in the HC-FET protocol were canceled due to failure in the thaw process or blastocysts degenerating prior to transfer. The remaining 197 patients in modified NC-FET protocol and 181 patients in HC-FET protocol underwent a total 225 and 218 FET cycles, respectively. There were 187 patients in the modified NC-FET and 175 in HC-FET protocol who underwent cumulative per patient analysis. Ten patients in modified NC-FET protocol and 6 patients in HC-FET protocol were excluded from cumulative per patient analysis as they switched protocols in subsequent cycles (mixed cycles). There were no significant differences between the two groups in clinical pregnancy rate from prior fresh cycle transfers and in the percentage of patients who underwent freeze-all after fresh cycle (data not provided). In addition, there were no significant differences between the two
groups in percentage of the various grades of the fresh blastocysts, early blastocysts or morulas (data not provided). Mean age, day-3 FSH, and percentage of patients with male factor infertility were significantly higher in NC-FET compared to HC-FET. Mean BMI was significantly lower in the NC-FET group. (Table I) For cycle characteristics, there were a significantly higher number of blastocysts transferred per cycle in the HC-FET group. (Table II) There were no significant differences in implantation rate (40.5% vs. 36.9%), chemical pregnancy rate (60.9% vs. 60.8%), clinical pregnancy rate (54.3% vs. 52.5%), or delivery rates (47.2% vs. 43.6%) between the modified NC-FET group and down-regulated HC FET group, respectively. (Table III) There were also no differences in pregnancy outcomes when comparing the two groups by cumulative pregnancy per patient. (Table IV) Subgroup analysis comparing pregnancy outcomes between patients who were ovulatory with regular cycles who underwent modified NC-FET protocol to those who underwent HC-FET protocol revealed no differences in clinical pregnancy for the first cycle (data not provided). A binary logistic regression analysis was performed to find a correlation between the baseline characteristics and pregnancy outcomes. (TABLE V) Age, number blastocyst transferred and year of FET were factors significantly impacting clinical pregnancy rate. We stratified the data into age groups to account for this bias. (TABLE VI) There were no significant differences in clinical pregnancy rate when comparing modified NC-FET and down-regulated HC-FET groups in patients≤35, between 36-39, and ≥40 years old. COMMENTS: Frozen embryo transfer has become a widely accepted practice in assisted reproductive technology, yet determining the optimal cryopreservation method and endometrial preparation protocols has been difficult. Recent evidence has shown that in cryopreserved cycles, blastocysts have improved outcomes compared with cleavage stage embryos. [12,13,14] More recent cryopreservation techniques have demonstrated more rapid freezing ability, improved post-thaw survival, and have not been associated with any increased adverse embryonic or obstetrical outcomes. [1,15] Our data suggests that there were no differences in clinical pregnancy, delivery, miscarriage and multiple pregnancy rates per transfer between the two protocols. Such findings remain the same after a subgroup analysis comparing pregnancy outcomes in patients with ovulatory cycles in the two protocols. Our findings support the notion that modified NC-FET protocol described in our study is as effective as down-regulated HC-FET, albeit is simpler and more tolerable by the patients. Therefore, we believe it should be the protocol of choice in patients who have regular and ovulatory cycles. In a traditional natural cycle protocol, endogenous LH level is measured throughout the cycle until levels reach above the LH-surge threshold before the embryo was transferred. [3] The modified NC-FET protocol differs from the traditional natural cycle protocol in that hCG is given to patients to trigger oocyte maturation and ovulation when follicular maturation and endometrial thickness reached a certain threshold without needing to measure the LH-surge. [4,8,16] There were variations in our modified NC-FET protocol compared to those in prior
studies. In our study, hCG was administered once LH-surge was confirmed by serum measurements as a supplement to the LH-surge. In a study by Weissman et al. (2011), hCG was not administered if a significant LH rise was observed. [17] The author suggested that this methodology could compromise the accuracy of timing frozen-thawed embryo transfer. We did not observe any detrimental effects when administering hCG after the LH-surge and achieved highly acceptable pregnancy outcomes. Though many patients prefer the NC-FET protocol because it does not require exogenous hormones to prime the endometrium, there are some known disadvantages. Because the accurate timing of ovulation is crucial for these patients undergoing the natural cycle protocol, more frequent visits are often needed to assess the endometrium. This is more difficult, especially when patients have some variability in their cycles. For this reason, the risk of cycle cancelation is potentially high. [18] However, the use of an hCG trigger for NC-FET can decrease the number of visits while aiding in estimation of implantation window without deleteriously effecting delivery rates. [17] On the other hand, we believe that less monitoring may lead to early administration of hCG when, in fact, the follicle size and function may not be optimal for its action. Ultimately, this may lead to an element of luteal phase insufficiency that may affect pregnancy outcome. Data by Kim et al. (2014) has shown that luteal phase support (LPS) with progesterone in NC-FET yields improved outcomes. [4] While their data did not show differences in pregnancy, implantation and multiple pregnancy rates between women who received LPS and those who did not, there was a significant decrease in miscarriage rate and a significant increase in live birth rate in women who received progesterone. The need for LPS is likely secondary to the fact that infertile women undergoing FET likely have suboptimal progesterone. [4] While the need for progesterone administration is highlighted, the most efficacious route of progesterone administration in HC-FET still needs to be determined. There are varying data in regards to the route of progesterone administration in HC-FET. Serum progesterone levels are shown to be higher with IM administration. [19] Pritts et al. (2002) found that IM progesterone was superior to vaginal administration. [20] However, some suggest that vaginal progesterone still provides comparable outcomes to intramuscular progesterone. [21] To our knowledge, the current study is the only one describing pregnancy outcomes in modified NC-FET and down-regulated HC-FET cycles using frozen-thawed blastocysts. In a meta-analysis by Groenewoud et al. (2013), the author stated that based on current literature, it is not possible to identify one method of endometrium preparation in FET more superior over the others. [3] However, the author did not analyze studies comparing modified NC-FET and downregulated HC-FET. Other studies concluded that natural endometrial preparation yielded better outcome in comparison to exogenous hormonal cycles. [6,22] Patients with normal ovarian function may achieve the best results using natural rather than hormonally manipulated cycles because exogenous estrogen may alter the physiologic concentration of endogenous hormone, resulting in negative effects on the endometrium. [7,23] When outcomes are similar between the two protocols, clinical decision should be based on cost and convenience for the patient. There are several reasons to suggest hormonally controlled cycles for patients undergoing frozen embryo transfers. First, HC-FET is necessary for most patients with irregular or absent menstrual cycles. A hormonally controlled cycle ensures an orderly maturation of the endometrium, which is critical for embryo implantation. Second, infertility specialists prefer this method because they have more control over the timing of the transfer. [3] Furthermore, patients require less office
visits to assess endometrial thickness and hormone levels compared to patients undergoing natural cycle FET. Despite all the advantages of HC-FET, it should be addressed that it introduces exogenous hormones to the patient. These medications are costly, providing a higher financial burden on patients, a burden that many are unable to surmount. If patients were able to successfully undergo NC- FET, then these burdens associated with HC-FET would be avoided. Therefore, the patient should be given the option of NC-FET in order to maintain autonomy through choice of cycle approach. Our study has a few limitations. The current study is retrospective in nature with the inherent biases associated with the study design. We acknowledge that, the comparison between the two groups in our study is limited because the two treatment groups are not comparable since patients in group 1 are ovulatory, while the majority of patients in group 2 have ovulatory disturbances. With that in mind, a subgroup analysis performed to account for this bias. Although we were not able to control for certain baseline characteristics, a multivariate log regression analysis showed age being the only significant factor impacting clinical pregnancy in our study. Large prospective, randomized trials should be conducted to confirm our findings.
ACKNOWLEDGEMENT: The authors would like to thank the staff at IVF Michigan for helping with data collection and Jenny LaChance from the Research Department at Hurley’s Medical Center for performing the statistical analysis. CONFLICT OF INTEREST: The authors in this study have no conflicts of interest to disclose.
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transfer with or without pretreatment with gonadotropin-releasing hormone agonist. Fertil Steril 2002; 77(5):956-60. [19] ASRM Practice Committee. Progesterone supplementation during the luteal phase in early pregnancy in the treatment of infertility: an educational bulletin. Fertil Stertil. 2008; 90:S1503. [20] Pritts, E., Atwood, A. Luteal phase support in infertility treatment: A meta-analysis of the randomized trials. Human Reprod. 2002. 17(9):2287-99. [21] Berger, BJ, Philips JA. Pregnancy outcomes in oocyte donation recipients: vaginal gel versus intramuscular injection progesterone replacement. Assist Reprod Genet. 2012; 29(3): 237–242. [22] Levron J, Yerushalmi GM, Brengauz M et al. Comparison between two protocols for thawed-embryo transfer: natural cycle versus exogenous hormone replacement. Gynecol Endocrinol 2014; 30(7):494-7. [23] Creus M, Ordi J, Fbregues F et al. The effect of different hormone therapies on integrin expression and pinopode formation in the human endometrium: a controlled study. Hum Reprod 2003; 18:683–93.
Figure 1: Flow Chart of the Population of the Study
428 Patients (493 Cycles)
Modified NC-FET (226 patients)
Down-reg. HC-FET
(202 patients)
Canceled
Canceled (29 patients)*
(21 patients)
197 patients (225 cycles)
187 patients Cumulative analysis
*
10 patients Excluded Mixed method**
*
181 patients (218 cycles)
175 patients Cumulative analysis
6 patients Excluded Mixed methods**
There is no difference in proportion of canceled cycles by patient. The cancelation rate was 12.8% in modified NCFET group vs.10.4% in the down-regulated HC-FET group (p=0.434) ** For cumulative analysis per group, patients that have undergone mixed methods in subsequent cycles were excluded from analysis
Table I: Baseline characteristics of the first cycle of patients in both groups Mod. NC-FET Down-reg. HC-FET (n=197) (n=181) a Mean Age (y) 34.3 ± 4.2 33.3 ± 4.8 2 a Mean BMI (kg/m ) 25.3 ± 5.5 27.7 ± 7.0 a Mean Basal FSH (mIU/mL) 6.6 ± 1.9 6.0 ± 3.3 Duration of infertility (y) a 3.3 ± 2.7 3.1 ± 2.6 Primary Infertility b 118 (59.9%) 122 (67.4%) Causes of Infertility Male factor b 139 (66.0%) 97 (53.6%) b Tubal factor 54 (27.4%) 52 (28.7%) b Ovulatory 0 (0.0%) 118 (65.2%)c Endometriosis b 54 (27.4%) 40 (22.1%) b Uterine 69 (35.0%) 58 (32.0%)
p-value 0.04 0.00 0.014 0.57 0.13 0.014 0.78 0.00 0.23 0.54
a
Values reported as mean ± SD Values reported as number of patients with percentage in parentheses c Sixty three patients (31.2%) with regular menstrual cycles elected to undergo modified HC-FET cycle b
Table II: Cycle characteristics of the first cycle of patients in both groups Mod. NC-FET Down-reg. HC(n=197) FET (n=181) Mean endometrial thickness (mm) a 9.6 ± 2.0 9.7 ± 2.1 a No. Blast. transferred/cycle 1.9 ± 0.7 2.1 ± 0.7 Cycles with High Grade Blast.b 66 (33.5%) 67 (37.0%) a b
Values reported as mean ± SD Value reported as number of patients with percentage in parentheses
Table III: Pregnancy Outcomes of the first cycle of patients in both groups Mod. NC-FET Down-reg. HC-FET (n=197) (n=181) Implantation Rate a 40.5% 36.4% b No. Chemical Pregnancy 120 (60.9%) 110 (60.8%) b No. Clinical Pregnancy 107 (54.3%) 95 (52.5%) b No. Delivery Pregnancy 93 (47.2%) 79 (43.6%) b No. Miscarriage 14 (13.1%) 16 (16.8%) b No. Ectopic Pregnancy 0 (0%) 2 (2.1%) No. Multiple Pregnancies b 25 (23.4%) 29 (30.5%) a b
p-value 0.69 0.006 0.48
Implantation rate is the number of sacs visualized Value reported as number of patients with percentage in parentheses
p-value 0.28 0.98 0.72 0.49 0.98 0.13 0.25
Table IV: Cumulative Pregnancy Outcomes Per Patient In Both Groups Mod. NC-FET Down-reg. HC-FET (n=187) (n=175) a No. Chemical Pregnancy 122 (65.2%) 112 (64.0%) a No. Clinical Pregnancy 111 (59.4%) 97 (55.4%) a No. Delivery Pregnancy 96 (51.3%) 82 (46.9%) No. Miscarriage a 15 (13.5%) 15 (15.4%) No. Ectopic Pregnancy a 0 (0%) 2 (2.1%) No. Multiple Pregnancies a 27 (24.3%) 30 (30.9%)
p-value 0.81 0.45 0.39 0.65 0.13 0.29
a
Data presented as number of patients followed by percentage in parentheses Cumulative pregnancy per patient includes the cycle with the best available pregnancy outcome for each patient (ie. if patient has undergone two cycles and had no chemical pregnancy after the first FET and a clinical pregnancy in the second, we only included the pregnancy data from the cycle where patient had the clinical pregnancy)
Table V: Multivariate logistic regression with clinical pregnancy as dependent variable Clinical Pregnancy OR (95% CI) p-value Age (years) a 0.939 (0.894 - 0.989) 0.011 2 a BMI (kg/m ) 0.98 (0.95 – 1.01) 0.25 Endometriosis (yes/no) a 0.90 (0.80 – 1.02) 0.09 a Basal FSH (mIU/mL) 1.02 (0.94 – 1.11) 0.62 Cycle Type (NC/HC) a 0.92 (0.59 – 1.44) 0.72 a No. Blast. transferred (#) 1.414 (1.046 – 1.909) 0.024 Year of FET (year) a 1.127 (1.029 – 1.234) 0.010 Data is presented as odds ratio with the 95% confidence interval in parentheses
Table VI: Age range Analysis with clinical pregnancy as dependent variable during the first cycle for each patient Clinical Pregnancy Mod. NC-FET Down-reg. HC-FET p-value ≤ 35 yrs n=93 a n=112 0.72 53 (57.0%) b 61 (54.5%) 36-39 yrs n=36 n=23 0.06 13 (36.1%) 14 (60.9%) ≥40 yrs n=15 n=15 0.46 5 (33.3%) 7(46.7%) a b
The number of patients in each group that meet a fall into a certain age range are reported on this table Numbers reported as number of patient with positive clinical pregnancy and percentage of patients in pregnancy