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Outcomes of subsequent pregnancies after conservative treatment for placenta accreta
International Journal of Gynecology and Obstetrics 127 (2014) 206–210
Contents lists available at ScienceDirect
International Journal of Gynecology and Obstetrics journal homepage: www.elsevier.com/locate/ijgo
CLINICAL ARTICLE
Outcomes of subsequent pregnancies after conservative treatment for placenta accreta☆ Doron Kabiri a,⁎,1, Yael Hants a,1, Neta Shanwetter a, Moshe Simons a, Carolyn F. Weiniger b, Yuval Gielchinsky a, Yossef Ezra a a b
Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel Department of Anesthesiology and Critical Care Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
a r t i c l e
i n f o
Article history: Received 22 December 2013 Received in revised form 20 May 2014 Accepted 26 June 2014 Keywords: Adherent placenta Conservative treatment Placenta accreta Postpartum hemorrhage
a b s t r a c t Objective: To estimate the association between conservative treatment for placenta accreta and subsequent pregnancy outcomes. Methods: In a retrospective study, data were analyzed on women who received conservative treatment for placenta accreta (removal of the placenta with uterine preservation) at a tertiary hospital in Jerusalem, Israel, between 1990 and 2000. Data were collected on subsequent pregnancies and neonatal outcomes until 2010, and compared with those from a matched control group of women who did not have placenta accreta. Results: A total of 134 women were included in both groups. Placenta accreta occurred in 62 (22.8%) of 272 subsequent deliveries in the study group for which data were available and 5 (1.9%) of 266 in the control group (relative risk [RR] 12.13; 95% confidence interval [CI] 4.95–29.69; P b 0.001). Early postpartum hemorrhage occurred in 23 (8.6%) of 268 deliveries in the study group and 7 (2.6%) of 268 in the control group (RR 3.29; 95% CI 1.43–7.53; P b 0.001). The odds ratio for recurrent placenta accreta in subsequent deliveries in the study group was 15.41 (95% CI 6.09–39.03; P b 0.001). Conclusion: Although subsequent pregnancies after conservative treatment for placenta accreta were mostly successful, the risk of recurrent placenta accreta and postpartum hemorrhage is high in future deliveries. © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.
1. Introduction Placenta accreta is a severe obstetric complication that is characterized by abnormal adherence of the placenta to the uterine wall. Histopathologically, it is characterized by partial or complete absence of the decidua basalis or the Nitabuch layer of the decidua, which results in abnormal attachment of the chorionic villi to the myometrium [1]. Placenta accreta can be a life-threatening obstetric condition; it is associated with high maternal morbidity and mortality due to uncontrolled bleeding, unplanned cesarean hysterectomy, and other complications resulting from abnormal invasion of the placenta into adjacent organs [2]. The reported incidence of placenta accreta has been rising constantly over the past few decades, and this disorder has become an important obstetric problem in medical practice [2–11].
To reduce maternal morbidity and mortality, elective cesarean hysterectomy in a tertiary care hospital with a multidisciplinary care team is considered to be the safest and most common treatment for placenta accreta diagnosed before delivery [9,12–17]. However, placenta accreta may be diagnosed after delivery, when the placenta or placental tissue fails to separate from the uterine wall. In an attempt to obtain an empty uterine cavity, systematic manual separation of the placenta from the uterine wall is usually performed. This forcible manual blunt dissection can induce massive hemorrhage, which may result in hysterectomy [2,18–20]. The aim of the present study was to estimate the association between conservative treatment for placenta accreta (removal of the placenta with uterine preservation) and subsequent pregnancy outcomes under the hypothesis that conservative treatment might negatively affect the obstetric outcomes of subsequent pregnancies. 2. Materials and methods
☆ Presented in part at the 32nd Annual Meeting of the Society for Maternal-Fetal Medicine; February 6–11, 2012; Dallas, TX, USA. ⁎ Corresponding author at: Department of Obstetrics and Gynecology, HadassahHebrew University Medical Center, Ein-Kerem, P.O. Box 12000, Jerusalem 9112001, Israel. Tel.: +972 50 8946898; fax: +972 2 6777541. E-mail address: [email protected] (D. Kabiri). 1 These authors contributed equally to this work.
The present retrospective cohort study analyzed data from women conservatively treated for placenta accreta at the maternal–fetal unit of the tertiary Hadassah-Hebrew University Medical Center, Jerusalem, Israel, between January 1, 1990, and December 31, 2000. In addition to the women who were treated for placenta accreta, the study enrolled
http://dx.doi.org/10.1016/j.ijgo.2014.05.013 0020-7292/© 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.
D. Kabiri et al. / International Journal of Gynecology and Obstetrics 127 (2014) 206–210
a control group of women who had a delivery in the study period and who were matched for parity and age (stratified by age group: b25 years, 25–29 years, 30–34 years, 35–39 years, and ≥ 40 years). The present study was approved by the institutional review board of the hospital on June 1, 2011 (reference number 0157-11-HMO), and all patients provided informed consent for participation by telephone. The cohort of patients has been used in other analyses [21,22]. Placenta accreta was diagnosed on the basis of sonographic, clinical, or histopathologic findings. Patients had to meet one or more of the following criteria [17,21,22]: (1) impossibility of, or incomplete, manual removal of the placenta with evidence of placental retention, despite active management of the third stage of labor (transabdominal manual massage of the uterus accompanied by controlled traction of the umbilical cord); (2) sonographic evidence of retained placental fragments requiring removal (curettage or hysteroscopy) after vaginal delivery; (3) heavy bleeding from the implantation site after placental removal during cesarean delivery with excision of part of the uterine wall and the attached placenta or oversewing of the bleeding defects; and (4) histologic confirmation of placenta accreta (invasion of chorionic villi to the myometrium). Women in the control group were selected from the registry database of the hospital in consecutive order by date of the index delivery. Clinical data for the present study—including maternal demographics, obstetric parameters, and subsequent pregnancy outcomes until 2010—were retrieved from the Ministry of Health Central Bureau of Statistics report and from patients’ medical records. Telephone interviews were conducted to obtain additional data regarding subsequent pregnancies, obstetric complications, and maternal and neonatal outcomes. Conservative management of placenta accreta was defined as removal of the placenta with uterine preservation. Early postpartum hemorrhage was defined as bleeding requiring medical or interventional treatment in the first 24 hours after delivery.
Statistical analysis was performed with SPSS version 18 (SPSS Inc, Chicago, IL, USA).The t test was used to assess differences in continuous variables between the two groups. Differences in categorical variables and in each of the dependent variables were analyzed via the χ2 or Fisher exact test. Odds ratios (ORs) were analyzed via a logistic regression model. P b 0.05 was considered statistically significant.
3. Results Between 1990 and 2000, there were 34 450 deliveries at the study institution and 260 women received conservative management for placenta accreta. Of these women, 99 (38.1%) were lost to follow-up, 5 (1.9%) lacked a matched control, and 22 (8.5%) declined to participate. As a result, subsequent pregnancy outcomes were compared between 134 women affected by placenta accreta (study group) and 134 women matched for age and obstetric history who did not have placenta accreta (control group) (Fig. 1, Table 1). The two groups were similar with regard to demographic and obstetric parameters; the only significant difference was a higher incidence of previous placenta accreta among patients in the study group (Table 2). Of the 107 women in the study group who attempted conception after placenta accreta, 99 (92.5%) successfully delivered live newborns, with 280 deliveries. 105 women in the control group attempted pregnancy after the index delivery, and 94 (89.5%) women achieved 271 deliveries (P = 0.205). Data for complications and outcomes were available for 272 subsequent deliveries in the study group and 266 deliveries in the control group. Placenta accreta occurred in 62 (22.8%) subsequent deliveries in the study group and 5 (1.9%) in the control group (relative risk [RR] 12.13; 95% confidence interval [CI] 4.95–29.69; P b 0.001) (Table 3). Early postpartum hemorrhage occurred in 23 (8.5%) and 7 (2.6%) deliveries in the study and control groups, respectively (RR 3.29; 95% CI
Deliveries between 1990 and 2000 (n=34 450)
Women with conservative treatment for placenta accreta (n=260)
Women lost to follow-up or declined to participate (n=126)
Women enrolled in the study group (n=134)
207
Women enrolled in the matched control group (n=134)
Fig. 1. Enrollment of the study participants.
208
D. Kabiri et al. / International Journal of Gynecology and Obstetrics 127 (2014) 206–210
Table 1 Matching criteria between the study and control groups.a Criterion Maternal age, y 18–24 25–29 30–34 35–39 ≥40 Mode of delivery Cesarean delivery Vaginal delivery Previous live births 0 1 2 3–5 ≥6 a
Study group (n = 134)
Table 3 Obstetric complications during subsequent pregnancies.a
Control group (n = 134)
P value
Complication
Subsequent deliveries
0.99 30 (22.4) 34 (25.4) 41 (30.6) 24 (17.9) 5 (3.7)
31 (23.1) 35 (26.1) 40 (29.9) 23 (17.2) 5 (3.7)
3 (2.2) 131 (97.8)
3 (2.2) 131 (97.8)
36 (26.9) 41 (30.6) 24 (17.9) 18 (13.4) 15 (11.2)
37 (27.6) 41 (30.6) 20 (14.9) 23 (17.2) 13 (9.7)
N0.99
0.90
Values are given as number (percentage) unless stated otherwise.
1.43–7.53; P b 0.001) (Table 3). The OR for recurrent placenta accreta during subsequent delivery in the study group was 15.41 (95% CI 6.09–39.03; P b 0.001). There were no significant differences in the rates of pregnancy complications, mode of delivery, or neonatal outcomes (Tables 3 and 4). To validate the results, three demographic and obstetric parameters known to be related to the incidence of placenta accreta—maternal age, number of pregnancies, and number of deliveries before the first extirpative treatment of the placenta accreta—were compared between women with conservatively managed placenta accreta who were included and excluded from the study group. Information on the parameters was obtained from medical records. The comparison revealed no differences (Table 5), reducing the likelihood of selection bias in the study.
4. Discussion In the present study, pregnancies after conservative treatment of placenta accreta were mostly successful. However, among the study group of women, there was an increased risk of the recurrence of placenta accreta and postpartum hemorrhage. Although conservative treatment is common when the diagnosis of placenta accreta is made after delivery, there have been few studies on the long-term effects of this treatment on subsequent pregnancies, deliveries, and neonatal outcomes [23]. The high recurrence rate observed in the present study might be associated with the factors that led to the initial placenta accreta, such as uterine factors (congenital anomalies and infection), placental factors (abnormal location and
Placenta accreta Yes No Early PPHb Yes No Placenta previac Yes No Preterm birth Twin pregnancy Gestational diabetes Hypertensive disorders Intra-uterine fetal death Placental abruption Cesarean delivery Postpartum infection
Study group (n = 272)
Control group (n = 266)
62 (22.8) 210 (77.2)
5 (1.9) 261 (98.1)
23 (8.6) 245 (91.4)
7 (2.6) 261 (97.4)
5 (1.9) 265 (98.1) 13 (4.7) 6 (2.2) 8 (2.9) 10 (3.7) 0 11 (3.7) 35 (12.9) 3 (1.1)
2 (0.8) 263 (99.2) 19 (7.1) 5 (1.9) 15 (5.6) 10 (3.8) 1 (0.4) 5 (1.9) 35 (13.2) 2 (0.8)
Relative risk (95% CI)
P value
12.13 (4.95–29.69)
b0.001
3.29 (1.43–7.53)
b0.001
2.45 (0.48–12.54)
0.280
0.6 (0.3–1.3) 1.16 (0.36–3.76) 0.51 (0.22–1.20) 0.97 (0.41–2.29) 0.32 (0.01–7.89) 2.13 (0.75–6.05) 0.97 (0.62–1.50) 1.45 (0.24–8.62)
0.235 0.802 0.123 0.941 0.488 0.156 0.884 0.682
Abbreviations: CI, confidence interval; PPH postpartum hemorrhage. a Values are given as number (percentage) unless stated otherwise. b Data available for 268 deliveries in the study group and 268 in the control group. c Data available for 270 deliveries in the study group and 265 in the control group.
developmental defects), and uterine scarring (previous curettage, cesarean delivery, and fibroid removal) [19,24]. A common problem in studies on placenta accreta is the definition of this condition: some studies are based on prenatal imaging criteria, some on clinical criteria, and others on histopathology. A literature search was conducted via Medline, PubMed, Embase, and the Cochrane Library for reports published between January 1, 2002, and December 31, 2012, using the keywords “placenta accreta,” “maternal outcomes,” and “neonatal outcomes,” to identify studies with methodologies similar to the present study. Because histologic examination is not always available when hysterectomy does not occur, in most recent studies, diagnosis of placenta accreta has been based on a combination of findings (Table 6). The present study used diagnostic criteria that were accepted in previous studies and were based on sonographic, clinical, or histologic parameters, and almost all cases fulfilled more than one diagnostic criterion. Selection bias due to the reliability of the inclusion criteria is unlikely given the differences between the groups in terms of recurrent placenta accreta and postpartum hemorrhage. The location of the placenta might influence the risk of recurrence of placenta accreta. The present study had a long follow-up period, which meant that it was not possible to retrieve placental location because this information was not contained within medical records. The higher
Table 2 Demographic and obstetric characteristics at the elected delivery by group.a Characteristics Demographic Maternal age Gravidity Parity Abortions Ectopic pregnancy Prior cesarean delivery Living children Previous placenta accreta Previous placenta previa Previous postpartum hemorrhage Obstetric Hypertension disorders Infections a
Study group (n = 134)
Control group (n = 134)
P value
30.58 2.71 1.92 0.71 0.04 0.08 1.95
30.4 2.64 2.07 0.56 0.01 0.11 1.98
0.925 0.879 0.456 0.263 0.174 0.410 0.992 b0.001 0.868 0.037
± ± ± ± ± ± ±
5.65 (21–44) 2.99 (0–13) 2.22 (0–10) 1.27 (0–9) 0.27 (0–2) 0.31 (0–3) 2.25 (0–10) 23 (17.2) 2 (1.5) 11 (8.2) 11 (8.2) 7 (5.2)
Values are given as mean ± SD (range) or number (percentage) unless stated otherwise.
± ± ± ± ± ± ±
5.77 (20–40) 2.89 (0–15) 2.32 (0–10) 1.09 (0–7) 0.09 (0–1) 0.28 (0–1) 2.33 (0–12) 4 (3.0) 3 (2.2) 3 (2.2) 4 (3.0) 4 (3.0)
0.104 0.372
D. Kabiri et al. / International Journal of Gynecology and Obstetrics 127 (2014) 206–210 Table 4 Neonatal outcomes during subsequent pregnancies.a Outcome
Study group (n = 286)
Control group (n = 276)
P value
Birth weight, g Gestation, wk Sex Male Female No. with 5-min Apgar score b7 No. admitted to NICU
3397 ± 493 39.9 ± 1.9
3294 ± 552 39.6 ± 1.9
0.31 0.44 0.51
153 (53.5) 133 (46.5) 0 0
149 (54.0) 127 (46.0) 0 0
N0.999 N0.999
Abbreviation: NICU, neonatal intensive care unit. a Values are given as mean ± SD or number (percentage), unless stated otherwise.
Table 5 Comparison of demographic and obstetric characteristics between women with conservatively managed placenta accreta who were and were not included in the study group.a Characteristic
Women in study group (n = 134)
Women excluded from study group (n = 126)
P value
Current maternal age, y No. of pregnancies before first extirpative treatment No. of deliveries before first extirpative treatment
46.03 ± 6.25 2.71 ± 2.99
45.86 ± 6.19 3.19 ± 2.43
0.836 0.176
1.91 ± 2.22
1.58 ± 1.88
0.226
a
209
The CI for the odds of recurrent placenta accreta was wide, which means that the estimation may be imprecise. A larger sample size would narrow the CI and strengthen the conclusions. In summary, although subsequent pregnancies after conservative treatment for placenta accreta were found to be mostly successful, appropriate preparations should be made to minimize morbidity and mortality resulting from the recurrence of placenta accreta and postpartum hemorrhage. Previous studies [3,7,25,26] have also shown that staff awareness and suitable preparations (including the preparation of blood products) may result in better treatment and a reduction in related risks, such as massive blood loss, consumption coagulopathy, unplanned cesarean hysterectomy, organ failure, and even death.
Conflict of interest The authors have no conflicts of interest.
References
Values are given as mean ± SD unless stated otherwise.
incidence of placenta accreta and postpartum hemorrhage in pregnancies before the index pregnancy among the study group was found only after data analysis, and might bias the results of the study. Additional studies may be needed to investigate the effect of these parameters on the risk of recurrent placenta accreta. Single-center studies have methodological advantages, such as unity in the care protocol and a relatively homogeneous population. Nevertheless, the external validity of these results might be limited. A study based on a larger cohort across multicenter databases might be warranted to validate the results. Recall bias and incomplete data sets are anticipated in every retrospective study; however, comparison of the results to a matched control group strengthens the validity of the present study’s results.
[1] Benirschke K, Kaufmann P, Baergen RN. Pathology of the Human Placenta. 5th ed. London: Springer; 2006. [2] Publications Committee, Society for Maternal–Fetal Medicine, Belfort MA. Placenta accreta. Am J Obstet Gynecol 2010;203(5):430–9. [3] Wortman AC, Alexander JM. Placenta accreta, increta, and percreta. Obstet Gynecol Clin North Am 2013;40(1):137–54. [4] Miller DA, Chollet JA, Goodwin TM. Clinical risk factors for placenta previa–placenta accreta. Am J Obstet Gynecol 1997;177(1):210–4. [5] ACOG Committee on Obstetric Practice. Number 266, January 2002: placenta accreta. Obstet Gynecol 2002;99(1):169–70. [6] Wu S, Kocherginsky M, Hibbard JU. Abnormal placentation: twenty-year analysis. Am J Obstet Gynecol 2005;192(5):1458–61. [7] Oyelese Y, Smulian JC. Placenta previa, placenta accreta, and vasa previa. Obstet Gynecol 2006;107(4):927–41. [8] Solheim KN, Esakoff TF, Little SE, Cheng YW, Sparks TN, Caughey AB. The effect of cesarean delivery rates on the future incidence of placenta previa, placenta accreta, and maternal mortality. J Matern Fetal Neonatal Med 2011;24(11):1341–6. [9] Committee on Obstetric Practice. Committee opinion no. 529: placenta accreta. Obstet Gynecol 2012;120(1):207–11. [10] Aggarwal R, Suneja A, Vaid NB, Yadav P, Sharma A, Mishra K. Morbidly adherent placenta: a critical review. J Obstet Gynaecol India 2012;62(1):57–61. [11] Royal College of Obstetricians and Gynaecologists. Placenta praevia, placenta praevia accreta and vasa praevia: diagnosis and management. Green-top Guideline No. 27. http://www.rcog.org.uk/files/rcog-corp/GTG27PlacentaPraeviaJanuary2011.pdf . Published January 2011. Accessed June 24, 2014.
Table 6 Diagnostic criteria of placenta accreta in recent clinical studies. Author
Year
Diagnostic criteria of placenta accreta
Journal
Gielchinsky et al. Gielchinsky et al. Kayem et al. Bretelle et al. Wu et al. Eller et al. Doumouchtsis et al. Provansal et al. Sentilhes et al. Sentilhes et al. Eller et al. Esh-Broder et al. Amsalem et al. Meyer et al. Aggarwal et al. Fitzpatrick et al. Eshkoli et al. Morlando et al. Kamara et al. Guleria et al. Kayem et al. Fitzpatrick et al. Higgins et al. Weiniger et al.
2002 2004 2004 2005 2005 2009 2010 2010 2010 2010 2011 2011 2011 2012 2012 2012 2013 2013 2013 2013 2013 2013 2013 2013
Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology Histology Histology Histology or clinical Histology or clinical Histology Histology or clinical Imaging, histology, or clinical Imaging, histology, or clinical Histology or clinical Histology or clinical Histology Imaging and clinical
Placenta Obstet Gynecol Obstet Gynecol Eur J Obstet Gynecol Am J Obstet Gynecol BJOG Acta Obstet Gynecol Scand Int J Obstet Gynecol Obstet Gynecol Hum Reprod Obstet Gynecol BJOG J Obstet Gynaecol Can Ceylon Med J J Obstet Gynecol India PLOS One AJOG Acta Obstet Gynecol Scand BJOG Acta Obstet Gynecol Scand Acta Obstet Gynecol Scand BJOG Eur J Obstet Reprod Biol Int J Obstet Anesth
210
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[12] Jolley JA, Nageotte MP, Wing DA, Shrivastava VK. Management of placenta accreta: a survey of Maternal–Fetal Medicine practitioners. J Matern Fetal Neonatal Med 2012;25(6):756–60. [13] Esakoff TF, Handler SJ, Granados JM, Caughey AB. PAMUS: placenta accreta management across the United States. J Matern Fetal Neonatal Med 2012;25(6):761–5. [14] Fox H. Placenta accreta: 1945-1969. Obstet Gynecol Surv 1972;27(7):475–90. [15] Eller AG, Porter TF, Soisson P, Silver RM. Optimal management strategies for placenta accreta. BJOG 2009;116(5):648–54. [16] Amsalem H, Kingdom JC, Farine D, Allen L, Yinon Y, D’Souza DL, et al. Planned caesarean hysterectomy versus “conserving” caesarean section in patients with placenta accreta. J Obstet Gynaecol Can 2011;33(10):1005–10. [17] Kayem G, Davy C, Goffinet F, Thomas C, Clément D, Cabrol D. Conservative versus extirpative management in cases of placenta accreta. Obstet Gynecol 2004;104(3): 531–6. [18] Bretelle F, Courbière B, Mazouni C, Agostini A, Cravello L, Boubli L, et al. Management of placenta accreta: morbidity and outcome. Eur J Obstet Gynecol Reprod Biol 2007;133(1):34–9.
[19] Jauniaux E, Jurkovic D. Placenta accreta: pathogenesis of a 20th century iatrogenic uterine disease. Placenta 2012;33(4):244–51. [20] Sentilhes L, Goffinet F, Kayem G. Management of placenta accreta. Acta Obstet Gynecol Scand 2013;92(10):1125–34. [21] Gielchinsky Y, Rojansky N, Fasouliotis SJ, Ezra Y. Placenta accreta–summary of 10 years: a survey of 310 cases. Placenta 2002;23(2–3):210–4. [22] Gielchinsky Y, Mankuta D, Rojansky N, Laufer N, Gielchinsky I, Ezra Y. Perinatal outcome of pregnancies complicated by placenta accreta. Obstet Gynecol 2004;104(3): 527–30. [23] Tandberg A, Albrechtsen S, Iversen OE. Manual removal of the placenta. Incidence and clinical significance. Acta Obstet Gynecol Scand 1999;78(1):33–6. [24] Hung TH, Shau WY, Hsieh CC, Chiu TH, Hsu JJ, Hsieh TT. Risk factors for placenta accreta. Obstet Gynecol 1999;93(4):545–50. [25] O’Brien JM, Barton JR, Donaldson ES. The management of placenta percreta: conservative and operative strategies. Am J Obstet Gynecol 1996;175(6):1632–8. [26] Hudon L, Belfort MA, Broome DR. Diagnosis and management of placenta percreta: a review. Obstet Gynecol Surv 1998;53(8):509–17.
Contents lists available at ScienceDirect
International Journal of Gynecology and Obstetrics journal homepage: www.elsevier.com/locate/ijgo
CLINICAL ARTICLE
Outcomes of subsequent pregnancies after conservative treatment for placenta accreta☆ Doron Kabiri a,⁎,1, Yael Hants a,1, Neta Shanwetter a, Moshe Simons a, Carolyn F. Weiniger b, Yuval Gielchinsky a, Yossef Ezra a a b
Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel Department of Anesthesiology and Critical Care Medicine, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
a r t i c l e
i n f o
Article history: Received 22 December 2013 Received in revised form 20 May 2014 Accepted 26 June 2014 Keywords: Adherent placenta Conservative treatment Placenta accreta Postpartum hemorrhage
a b s t r a c t Objective: To estimate the association between conservative treatment for placenta accreta and subsequent pregnancy outcomes. Methods: In a retrospective study, data were analyzed on women who received conservative treatment for placenta accreta (removal of the placenta with uterine preservation) at a tertiary hospital in Jerusalem, Israel, between 1990 and 2000. Data were collected on subsequent pregnancies and neonatal outcomes until 2010, and compared with those from a matched control group of women who did not have placenta accreta. Results: A total of 134 women were included in both groups. Placenta accreta occurred in 62 (22.8%) of 272 subsequent deliveries in the study group for which data were available and 5 (1.9%) of 266 in the control group (relative risk [RR] 12.13; 95% confidence interval [CI] 4.95–29.69; P b 0.001). Early postpartum hemorrhage occurred in 23 (8.6%) of 268 deliveries in the study group and 7 (2.6%) of 268 in the control group (RR 3.29; 95% CI 1.43–7.53; P b 0.001). The odds ratio for recurrent placenta accreta in subsequent deliveries in the study group was 15.41 (95% CI 6.09–39.03; P b 0.001). Conclusion: Although subsequent pregnancies after conservative treatment for placenta accreta were mostly successful, the risk of recurrent placenta accreta and postpartum hemorrhage is high in future deliveries. © 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.
1. Introduction Placenta accreta is a severe obstetric complication that is characterized by abnormal adherence of the placenta to the uterine wall. Histopathologically, it is characterized by partial or complete absence of the decidua basalis or the Nitabuch layer of the decidua, which results in abnormal attachment of the chorionic villi to the myometrium [1]. Placenta accreta can be a life-threatening obstetric condition; it is associated with high maternal morbidity and mortality due to uncontrolled bleeding, unplanned cesarean hysterectomy, and other complications resulting from abnormal invasion of the placenta into adjacent organs [2]. The reported incidence of placenta accreta has been rising constantly over the past few decades, and this disorder has become an important obstetric problem in medical practice [2–11].
To reduce maternal morbidity and mortality, elective cesarean hysterectomy in a tertiary care hospital with a multidisciplinary care team is considered to be the safest and most common treatment for placenta accreta diagnosed before delivery [9,12–17]. However, placenta accreta may be diagnosed after delivery, when the placenta or placental tissue fails to separate from the uterine wall. In an attempt to obtain an empty uterine cavity, systematic manual separation of the placenta from the uterine wall is usually performed. This forcible manual blunt dissection can induce massive hemorrhage, which may result in hysterectomy [2,18–20]. The aim of the present study was to estimate the association between conservative treatment for placenta accreta (removal of the placenta with uterine preservation) and subsequent pregnancy outcomes under the hypothesis that conservative treatment might negatively affect the obstetric outcomes of subsequent pregnancies. 2. Materials and methods
☆ Presented in part at the 32nd Annual Meeting of the Society for Maternal-Fetal Medicine; February 6–11, 2012; Dallas, TX, USA. ⁎ Corresponding author at: Department of Obstetrics and Gynecology, HadassahHebrew University Medical Center, Ein-Kerem, P.O. Box 12000, Jerusalem 9112001, Israel. Tel.: +972 50 8946898; fax: +972 2 6777541. E-mail address: [email protected] (D. Kabiri). 1 These authors contributed equally to this work.
The present retrospective cohort study analyzed data from women conservatively treated for placenta accreta at the maternal–fetal unit of the tertiary Hadassah-Hebrew University Medical Center, Jerusalem, Israel, between January 1, 1990, and December 31, 2000. In addition to the women who were treated for placenta accreta, the study enrolled
http://dx.doi.org/10.1016/j.ijgo.2014.05.013 0020-7292/© 2014 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.
D. Kabiri et al. / International Journal of Gynecology and Obstetrics 127 (2014) 206–210
a control group of women who had a delivery in the study period and who were matched for parity and age (stratified by age group: b25 years, 25–29 years, 30–34 years, 35–39 years, and ≥ 40 years). The present study was approved by the institutional review board of the hospital on June 1, 2011 (reference number 0157-11-HMO), and all patients provided informed consent for participation by telephone. The cohort of patients has been used in other analyses [21,22]. Placenta accreta was diagnosed on the basis of sonographic, clinical, or histopathologic findings. Patients had to meet one or more of the following criteria [17,21,22]: (1) impossibility of, or incomplete, manual removal of the placenta with evidence of placental retention, despite active management of the third stage of labor (transabdominal manual massage of the uterus accompanied by controlled traction of the umbilical cord); (2) sonographic evidence of retained placental fragments requiring removal (curettage or hysteroscopy) after vaginal delivery; (3) heavy bleeding from the implantation site after placental removal during cesarean delivery with excision of part of the uterine wall and the attached placenta or oversewing of the bleeding defects; and (4) histologic confirmation of placenta accreta (invasion of chorionic villi to the myometrium). Women in the control group were selected from the registry database of the hospital in consecutive order by date of the index delivery. Clinical data for the present study—including maternal demographics, obstetric parameters, and subsequent pregnancy outcomes until 2010—were retrieved from the Ministry of Health Central Bureau of Statistics report and from patients’ medical records. Telephone interviews were conducted to obtain additional data regarding subsequent pregnancies, obstetric complications, and maternal and neonatal outcomes. Conservative management of placenta accreta was defined as removal of the placenta with uterine preservation. Early postpartum hemorrhage was defined as bleeding requiring medical or interventional treatment in the first 24 hours after delivery.
Statistical analysis was performed with SPSS version 18 (SPSS Inc, Chicago, IL, USA).The t test was used to assess differences in continuous variables between the two groups. Differences in categorical variables and in each of the dependent variables were analyzed via the χ2 or Fisher exact test. Odds ratios (ORs) were analyzed via a logistic regression model. P b 0.05 was considered statistically significant.
3. Results Between 1990 and 2000, there were 34 450 deliveries at the study institution and 260 women received conservative management for placenta accreta. Of these women, 99 (38.1%) were lost to follow-up, 5 (1.9%) lacked a matched control, and 22 (8.5%) declined to participate. As a result, subsequent pregnancy outcomes were compared between 134 women affected by placenta accreta (study group) and 134 women matched for age and obstetric history who did not have placenta accreta (control group) (Fig. 1, Table 1). The two groups were similar with regard to demographic and obstetric parameters; the only significant difference was a higher incidence of previous placenta accreta among patients in the study group (Table 2). Of the 107 women in the study group who attempted conception after placenta accreta, 99 (92.5%) successfully delivered live newborns, with 280 deliveries. 105 women in the control group attempted pregnancy after the index delivery, and 94 (89.5%) women achieved 271 deliveries (P = 0.205). Data for complications and outcomes were available for 272 subsequent deliveries in the study group and 266 deliveries in the control group. Placenta accreta occurred in 62 (22.8%) subsequent deliveries in the study group and 5 (1.9%) in the control group (relative risk [RR] 12.13; 95% confidence interval [CI] 4.95–29.69; P b 0.001) (Table 3). Early postpartum hemorrhage occurred in 23 (8.5%) and 7 (2.6%) deliveries in the study and control groups, respectively (RR 3.29; 95% CI
Deliveries between 1990 and 2000 (n=34 450)
Women with conservative treatment for placenta accreta (n=260)
Women lost to follow-up or declined to participate (n=126)
Women enrolled in the study group (n=134)
207
Women enrolled in the matched control group (n=134)
Fig. 1. Enrollment of the study participants.
208
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Table 1 Matching criteria between the study and control groups.a Criterion Maternal age, y 18–24 25–29 30–34 35–39 ≥40 Mode of delivery Cesarean delivery Vaginal delivery Previous live births 0 1 2 3–5 ≥6 a
Study group (n = 134)
Table 3 Obstetric complications during subsequent pregnancies.a
Control group (n = 134)
P value
Complication
Subsequent deliveries
0.99 30 (22.4) 34 (25.4) 41 (30.6) 24 (17.9) 5 (3.7)
31 (23.1) 35 (26.1) 40 (29.9) 23 (17.2) 5 (3.7)
3 (2.2) 131 (97.8)
3 (2.2) 131 (97.8)
36 (26.9) 41 (30.6) 24 (17.9) 18 (13.4) 15 (11.2)
37 (27.6) 41 (30.6) 20 (14.9) 23 (17.2) 13 (9.7)
N0.99
0.90
Values are given as number (percentage) unless stated otherwise.
1.43–7.53; P b 0.001) (Table 3). The OR for recurrent placenta accreta during subsequent delivery in the study group was 15.41 (95% CI 6.09–39.03; P b 0.001). There were no significant differences in the rates of pregnancy complications, mode of delivery, or neonatal outcomes (Tables 3 and 4). To validate the results, three demographic and obstetric parameters known to be related to the incidence of placenta accreta—maternal age, number of pregnancies, and number of deliveries before the first extirpative treatment of the placenta accreta—were compared between women with conservatively managed placenta accreta who were included and excluded from the study group. Information on the parameters was obtained from medical records. The comparison revealed no differences (Table 5), reducing the likelihood of selection bias in the study.
4. Discussion In the present study, pregnancies after conservative treatment of placenta accreta were mostly successful. However, among the study group of women, there was an increased risk of the recurrence of placenta accreta and postpartum hemorrhage. Although conservative treatment is common when the diagnosis of placenta accreta is made after delivery, there have been few studies on the long-term effects of this treatment on subsequent pregnancies, deliveries, and neonatal outcomes [23]. The high recurrence rate observed in the present study might be associated with the factors that led to the initial placenta accreta, such as uterine factors (congenital anomalies and infection), placental factors (abnormal location and
Placenta accreta Yes No Early PPHb Yes No Placenta previac Yes No Preterm birth Twin pregnancy Gestational diabetes Hypertensive disorders Intra-uterine fetal death Placental abruption Cesarean delivery Postpartum infection
Study group (n = 272)
Control group (n = 266)
62 (22.8) 210 (77.2)
5 (1.9) 261 (98.1)
23 (8.6) 245 (91.4)
7 (2.6) 261 (97.4)
5 (1.9) 265 (98.1) 13 (4.7) 6 (2.2) 8 (2.9) 10 (3.7) 0 11 (3.7) 35 (12.9) 3 (1.1)
2 (0.8) 263 (99.2) 19 (7.1) 5 (1.9) 15 (5.6) 10 (3.8) 1 (0.4) 5 (1.9) 35 (13.2) 2 (0.8)
Relative risk (95% CI)
P value
12.13 (4.95–29.69)
b0.001
3.29 (1.43–7.53)
b0.001
2.45 (0.48–12.54)
0.280
0.6 (0.3–1.3) 1.16 (0.36–3.76) 0.51 (0.22–1.20) 0.97 (0.41–2.29) 0.32 (0.01–7.89) 2.13 (0.75–6.05) 0.97 (0.62–1.50) 1.45 (0.24–8.62)
0.235 0.802 0.123 0.941 0.488 0.156 0.884 0.682
Abbreviations: CI, confidence interval; PPH postpartum hemorrhage. a Values are given as number (percentage) unless stated otherwise. b Data available for 268 deliveries in the study group and 268 in the control group. c Data available for 270 deliveries in the study group and 265 in the control group.
developmental defects), and uterine scarring (previous curettage, cesarean delivery, and fibroid removal) [19,24]. A common problem in studies on placenta accreta is the definition of this condition: some studies are based on prenatal imaging criteria, some on clinical criteria, and others on histopathology. A literature search was conducted via Medline, PubMed, Embase, and the Cochrane Library for reports published between January 1, 2002, and December 31, 2012, using the keywords “placenta accreta,” “maternal outcomes,” and “neonatal outcomes,” to identify studies with methodologies similar to the present study. Because histologic examination is not always available when hysterectomy does not occur, in most recent studies, diagnosis of placenta accreta has been based on a combination of findings (Table 6). The present study used diagnostic criteria that were accepted in previous studies and were based on sonographic, clinical, or histologic parameters, and almost all cases fulfilled more than one diagnostic criterion. Selection bias due to the reliability of the inclusion criteria is unlikely given the differences between the groups in terms of recurrent placenta accreta and postpartum hemorrhage. The location of the placenta might influence the risk of recurrence of placenta accreta. The present study had a long follow-up period, which meant that it was not possible to retrieve placental location because this information was not contained within medical records. The higher
Table 2 Demographic and obstetric characteristics at the elected delivery by group.a Characteristics Demographic Maternal age Gravidity Parity Abortions Ectopic pregnancy Prior cesarean delivery Living children Previous placenta accreta Previous placenta previa Previous postpartum hemorrhage Obstetric Hypertension disorders Infections a
Study group (n = 134)
Control group (n = 134)
P value
30.58 2.71 1.92 0.71 0.04 0.08 1.95
30.4 2.64 2.07 0.56 0.01 0.11 1.98
0.925 0.879 0.456 0.263 0.174 0.410 0.992 b0.001 0.868 0.037
± ± ± ± ± ± ±
5.65 (21–44) 2.99 (0–13) 2.22 (0–10) 1.27 (0–9) 0.27 (0–2) 0.31 (0–3) 2.25 (0–10) 23 (17.2) 2 (1.5) 11 (8.2) 11 (8.2) 7 (5.2)
Values are given as mean ± SD (range) or number (percentage) unless stated otherwise.
± ± ± ± ± ± ±
5.77 (20–40) 2.89 (0–15) 2.32 (0–10) 1.09 (0–7) 0.09 (0–1) 0.28 (0–1) 2.33 (0–12) 4 (3.0) 3 (2.2) 3 (2.2) 4 (3.0) 4 (3.0)
0.104 0.372
D. Kabiri et al. / International Journal of Gynecology and Obstetrics 127 (2014) 206–210 Table 4 Neonatal outcomes during subsequent pregnancies.a Outcome
Study group (n = 286)
Control group (n = 276)
P value
Birth weight, g Gestation, wk Sex Male Female No. with 5-min Apgar score b7 No. admitted to NICU
3397 ± 493 39.9 ± 1.9
3294 ± 552 39.6 ± 1.9
0.31 0.44 0.51
153 (53.5) 133 (46.5) 0 0
149 (54.0) 127 (46.0) 0 0
N0.999 N0.999
Abbreviation: NICU, neonatal intensive care unit. a Values are given as mean ± SD or number (percentage), unless stated otherwise.
Table 5 Comparison of demographic and obstetric characteristics between women with conservatively managed placenta accreta who were and were not included in the study group.a Characteristic
Women in study group (n = 134)
Women excluded from study group (n = 126)
P value
Current maternal age, y No. of pregnancies before first extirpative treatment No. of deliveries before first extirpative treatment
46.03 ± 6.25 2.71 ± 2.99
45.86 ± 6.19 3.19 ± 2.43
0.836 0.176
1.91 ± 2.22
1.58 ± 1.88
0.226
a
209
The CI for the odds of recurrent placenta accreta was wide, which means that the estimation may be imprecise. A larger sample size would narrow the CI and strengthen the conclusions. In summary, although subsequent pregnancies after conservative treatment for placenta accreta were found to be mostly successful, appropriate preparations should be made to minimize morbidity and mortality resulting from the recurrence of placenta accreta and postpartum hemorrhage. Previous studies [3,7,25,26] have also shown that staff awareness and suitable preparations (including the preparation of blood products) may result in better treatment and a reduction in related risks, such as massive blood loss, consumption coagulopathy, unplanned cesarean hysterectomy, organ failure, and even death.
Conflict of interest The authors have no conflicts of interest.
References
Values are given as mean ± SD unless stated otherwise.
incidence of placenta accreta and postpartum hemorrhage in pregnancies before the index pregnancy among the study group was found only after data analysis, and might bias the results of the study. Additional studies may be needed to investigate the effect of these parameters on the risk of recurrent placenta accreta. Single-center studies have methodological advantages, such as unity in the care protocol and a relatively homogeneous population. Nevertheless, the external validity of these results might be limited. A study based on a larger cohort across multicenter databases might be warranted to validate the results. Recall bias and incomplete data sets are anticipated in every retrospective study; however, comparison of the results to a matched control group strengthens the validity of the present study’s results.
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Table 6 Diagnostic criteria of placenta accreta in recent clinical studies. Author
Year
Diagnostic criteria of placenta accreta
Journal
Gielchinsky et al. Gielchinsky et al. Kayem et al. Bretelle et al. Wu et al. Eller et al. Doumouchtsis et al. Provansal et al. Sentilhes et al. Sentilhes et al. Eller et al. Esh-Broder et al. Amsalem et al. Meyer et al. Aggarwal et al. Fitzpatrick et al. Eshkoli et al. Morlando et al. Kamara et al. Guleria et al. Kayem et al. Fitzpatrick et al. Higgins et al. Weiniger et al.
2002 2004 2004 2005 2005 2009 2010 2010 2010 2010 2011 2011 2011 2012 2012 2012 2013 2013 2013 2013 2013 2013 2013 2013
Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology or clinical Histology Histology Histology Histology or clinical Histology or clinical Histology Histology or clinical Imaging, histology, or clinical Imaging, histology, or clinical Histology or clinical Histology or clinical Histology Imaging and clinical
Placenta Obstet Gynecol Obstet Gynecol Eur J Obstet Gynecol Am J Obstet Gynecol BJOG Acta Obstet Gynecol Scand Int J Obstet Gynecol Obstet Gynecol Hum Reprod Obstet Gynecol BJOG J Obstet Gynaecol Can Ceylon Med J J Obstet Gynecol India PLOS One AJOG Acta Obstet Gynecol Scand BJOG Acta Obstet Gynecol Scand Acta Obstet Gynecol Scand BJOG Eur J Obstet Reprod Biol Int J Obstet Anesth
210
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