- Email: [email protected]
An obstetric assessment of the first 100 births from the in vitro fertilization program at Clamart, France
Goldberg et al.
6. O'Sullivan JB, Mahan CM. Criteria for the oral glucose tolerance test in pregnancy. Diabetes 1964; 13:278. 7. Carpenter MW, Coustan D. Criteria for screening tests for gestational diabetes. AM J OBSTET GYNECOL 1982; 144:768. 8. McNemar Q. Note on the sampling error of the difference between correlated proportions or percentages. Psychometrica 1947;12:153. 9. Pedersen J. The pregnant diabetic and her newborn. 2nd ed. Baltimore, Maryland: Williams & Wilkins, 1977:211. 10. O'SullivanJB, Mahan CM, Charles D, Dandrow RV. Med-
March, 1986 Am J Obstet Gynecol
ical treatment of the gestational diabetic. Obstet Gynecol 1974;43:817. II. Coustan DR, Lewis SB. Insulin therapy for gestational diabetes. Obstet Gynecol 1978;51 :306. 12. Roversi GD, Gargiulo M, Nicolini V, et al. Maximal tolerated insulin therapy in gestational diabetics. Diabetes Care 1980;3:489. 13. Metzger BE, Phelps R, Freinkel N. Predictive value of fasting plasma glucose in gestational diabetes mellitus. Diabetes 1981 ;30:4A.
An obstetric assessment of the first 100 births from the in vitro fertilization program at Clamart, France Rene Frydman, M.D., Joelle Belaisch-Allart, M.D., Nicolas Fries, M.D., Andre Hazout, M.D., Amelie Glissant, M.D., and Jacques Testart, Ph.D. Clamart, France From April, 1981, to July, 1984, 142 pregnancies have been attained after in vitro fertilization and embryo transfer. They are divided into 22 biochemical pregnancies (human chorionic gonadotropin ;;020 mU/ml but remaining below 1000 mU/ml), 27 spontaneous abortions, three ectopiC pregnancies, and 90 ongoing pregnancies, of which 11 were twin pregnancies. The 90 women in whom the pregnancies progressed were compared with the 52 women having non progressive pregnancies. The two populations did not differ either in age, in the indication for in vitro fertilization and embryo transfer, or in the quality of ovulation or results of semen analysis. The 90 ongoing pregnancies were compared with those pregnancies occurring in the same obstetrics department during this period. We found that the in vitro fertilization group had a higher proportion of arterial hypertension (16.5% versus 8.5%, p < 0.05), breech presentations (13.9% versus 4.3%, p < 0.001), and caesarean sections (46.8% versus 15.5%, p < 0.001) but the sex ratio did not differ. (AM J OasTET GVNECOL 1986;154:550-5.)
Key words: In vitro fertilization and embryo transfer, obstetric outcome
After the success of Edwards and Steptoe,! the procedure of in vitro fertilization and embryo transfer has become one of the possible treatments for certain types of infertility. More than 2000 children have been conceived by this method. Little information is available on the outcome of these pregnancies as the patients are not usually delivered in the in vitro fertilization center. At Clamart, the in vitro fertilization center is part of the obstetrics department and this enables us to follow up most of the pregnancies and to establish a register of both the pregnancies and the births for all patients. We present in this paper an assessment of the first 142 pregnancies. We have compared the spontaneous abor-
From the Department d'Obstetrique et Gynecologie (Pr. E. Papiernik), H6pital Antoine Beciere, and the Unite Institut National de la Sante et de La Recherche Medicale 187 (Pr. E. Papiernik). Received for publication August 23. 1985; accepted November 7. 1985. Reprint requests: R. Frydman, H6pital A. Beclere, 92141 Clamart, France.
550
tion rate, fetal growth, obstetric complications, and method of delivery in these pregnancies with those occurring after spontaneous pregnancies as well as after induction of ovulation.
Patients and methods From April, 1981, when the first in vitro pregnancy occurred-which ended as a spontaneous abortion 2to July, 1984, when the one hundredth baby was conceived, 1280 oocyte retrievals were performed for in vitro fertilization and 142 pregnancies commenced. All patients included in the in vitro fertilization program had a preliminary workup comprising an assessment of ovulation, a semen analysis, and an assessment of previous surgical procedures to decide whether they needed a laparoscopic examination. All 142 pregnancies occurred after ovulation induction. A combination of clomiphene citrate (Merrell Torraude, Paris, France) and human menopausal gonadotropins (Inductor, Searle, Paris, France) was used in 94% of the
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Table I. Population analysis N onprogressive pregnancies
No. Age (yr) Sterility (%) Primary Secondary Indication for in vitro fertilization (%) Tubal sterility Immunologic Idiopathic Normal ovulation (%) Normal semen analysis (%)
90 32.1 ± 3.3
39 61
92 4.5
88 1.9 3.8 55.3 85.2
1.1
58.2 91.3
Table II. N umber of embryos transferred and the progress of the 142 pregnancies No. of embryos transferred
52 32.8 ± 3.9
44 56
cases. In all but four cases human chorionic gonadotropin (hCG) was given in lieu of the ovulatory surge and oocyte recovery took place 35 ± I hours afterward, either laparoscopically with the patient under general or local anaesthesia or with ultrasonographic guidance according to previously described techniques.' The details of ovulation monitoring and of in vitro culture techniques have been described elsewhere.'· 4 After embryo transfer the only treatment given was dydrogesterone (Duphaston, Duphar, Villeurbanne, France) in known cases of luteal insufficiency. Commencing on the eleventh day after oocyte aspiration (13 days after the administration of hCG) the serum levels of hCG were measured by radioimmunoassay every 2 days. The assays were repeated every 2 days until the twenty-third day, then weekly for the first 10 weeks of amenorrhea. Ultrasonography was performed around the eighth week of amenorrhea. We defined biochemical pregnancy by an hCG value ~20 mIU/ml on two occasions after the eleventh day following aspiration but never exceeding 1000 mIU/ml.' In fact when this last value was reached, a gestational sac was always detected by the ultrasound scan and the pregnancy had become clinical. Should the pregnancy I then not proceed, we termed it a spontaneous abortion. This classification of pregnancy is similar to that of Edwards and Steptoe6 but differs from that of Jones et al.,7 as we found that with the use of clomiphene and human menopausal gonadotropins, 50% of the luteal phases exceed 15 days in the absence of a pregnancy.' The 142 pregnancies were divided in the following way: A total of 90 pregnancies progressed to term, and among these there were 11 twin pregnancies and 79 singleton pregnancies resulting in 100 living babies and one intrauterine death. There were 22 biochemical pregnancies, and 27 pregnancies terminated as spontaneous abortions. Three ectopic pregnancies occurred during this period. First of all we have compared the ongoing pregnan-
551
1
Total No. transferred Ongoing pregnancies (% of all pregnancies) Twin pregnancies (% of ongoing pregnancies)
3
50 66
57 60
35 66
0
21
22
cies with those that failed to progress; then we have compared the in vitro pregnancies with those obtained after induction of ovulation as well as with all pregnancies with delivery at Antoine Beclere Hospital during the same period. We looked at the singleton and multiple pregnancies separately. Statistical method. Sample means were compared by means of Student's t tests and proportions compared by X2 analysis. Means are expressed together with the standard deviation.
Results Comparison between ongoing and non progressive in vitro pregnancies Population analysis (Table I). The proportion of patients with primary or secondary sterility and the indication for in vitro fertilization did not differ between the two groups. Ninety percent of patients in the program were candidates for in vitro fertilization on account of tubal sterility. Similarly the percentages with normal ovulation and normal results of semen analysis did not differ. Mean age of patients who aborted (32.8 years) was the same as that of those in whom pregnancy progressed (32.1 years). The proportions of laparoscopic oocyte recovery of ultrasonically guided puncture were the same in the two groups (81 % and 82% laparoscopic oocyte recovery). Biochemical pregnancies. The level of hCG remained below 300 mIU/ml in 20 of the 22 cases and between 300 and 1000 in two cases. In 18 cases the hCG threshold' appeared more than 13 days after follicular puncture and there was an inadequate rise from one measurement to the other. 8 The duration of the luteal phase had been prolonged from 0 to 15 days with a mean of 5 days. Spontaneous abortions. These occurred most often between the sixth and twelfth weeks of amenorrhea (25 cases). The explusion of the fetus was always delayed in relation to the fall in hCG, even necessitating an aspiration of the uterine cavity in five cases where the fetus had not been expelled 1 month after the pregnancy terminated. In the 27 cases, only six chromosomal analyses could be performed. Two were normal,
552
Frydman et al.
March, 1986 Am J Obstet Gynecol
Table III. Analysis of the three preganancy groups (excluding twins)
No. Age (yr) Primigravid (%) No. of consultations Weight gain (kg)
Spontaneous (control) pregnancies
In vitro fertilization pregnancies
Induced ovulation pregnancies
3841 28.6 ± 4.2* 46.2* 6.9 ± 3.7* 12.8 ± 3.7
79 32.5 ± 3.5 83.5 8.3 ± 2.1 12.9 ± 3.6
142* 29.3 ± 4.2 57.8 6.8 ± 1.6 12.6 ± 3.6
Mean ± SD. *p < 0.001.
Table IV. Pregnancy complications (excluding twins) Spontaneous (control) pregnancies
No. First-trimester bleeding No. % All pregnancies Threatened premature delivery No. % All pregnancies Arterial hypertension No. % All pregnancies Fetal growth retardation No. % All pregnancies
In vitro fertilization pregnancies
Induced ovulation pregnancies
3841
79
142
374 9.7
12 15.2
19 13.4
420
6
10.9
7.6
23 16.2
327* 8.5
13 16.5
13 9.1
443 11.5
7
14.8
21 14.8
*p < 0.05.
one revealed a monosomy 45,X, and the other three showed trisomies 20, 22, and 15. Only two abortions were recorded later than 12 weeks, one in a twin pregnancy at 17 weeks and the other at 18 weeks associated with a pyrexia after amniocentesis. Ectopic pregnancies. Among the three ectopic pregnancies, two were easily diagnosed at 7 weeks of amenorrhea by ultrasound and the levels ofhCG. These were ampullary ectopic pregnancies in patients who had a past history of tubal surgical procedures and who were known to have hydrosalpinges. The third was a pregnancy implanted in the right uterine cornu in a woman who had previously undergone a right salpingectomy for an ectopic pregnancy. The diagnosis was made only at 10 weeks of amenorrhea when she presented with the signs of a hemoperitoneum. Number of embryos transferred (Table II). When a pregnancy occurred, whatever the number of embryos transferred, the percentage of ongoing pregnancies was around 60. The percentage of twin pregnancies was virtually the same whether two or three embryos were transferred (21 and 22). The 11 sets of twins developed from the transfer of two embryos in six cases and three embryos in five cases. Of the 27 abortions, two occurred in the course of a known twin pregnancy (after the transfer of two embryos in both cases). However, as the first ultrasound examination was requested
only after 8 weeks of amenorrhea, there must be a certain number of early twin pregnancies, of which we are unaware, that subsequently become singleton gestations. Comparison of the singleton in vitro ongoing pregnancies (n = 79) with the induced (n = 142) and control (n 3841) pregnancies Age, parity, and antenatal progress (Table III). The patients who had successful in vitro fertilization were older than the women with ind uction of labor and those with spontaneous pregnancies (p < 0.001). The proportion of primigravid women in the in vitro fertilization group was higher than in the other two groups (p < 0.001). The number of antenatal consultations was much greater in the in vitro fertilization patients but the weight gain was identical in all three groups. The first 10 patients who became pregnant after in vitro fertilization systematically underwent amniocentesis, but in the remainder only those patients in whom amniocentesis was justified on account of their age or past obstetric history were submitted to it. 9 Pregnancy complications (Table IV). We limited ourselves to studying bleeding in the first trimester, threatened premature delivery justifying hospitalization, fetal growth retardation, and hypertension requiring treatment. The percentage of threatened premature deliveries tended to be lower in the in vitro pregnancies, as
=
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553
Table V. Outcome of deliveries Spontaneous (control) pregnancies
No. Premature deliveries No. % All deliveries Cesarean sections No. % All deliveries Breech presentations No. % All deliveries Sex ratio Girls (%) Boys (%) Birth weight (gm)
In vitro fertilization pregnancies
3841
79
144
5
Induced ovulation pregnancies
142
3.7
6.3
13 9.1
597 15.5*
37 46.8*
31 21.8
166 4.3*
II
8 5.6
13.9*
46.9 53.1 3273 ::!: 490
55.7 44.3 3249 ::!: 460
46.5 53.5 3142 ::!: 557
*p < 0.001.
Table VI. Twin pregnancies Spontaneous (control) pregnancies
Total No. of pregnancies No. of twin pregnancies Frequency of twin pregnancy (%) Cesarean sections No. % All deliveries
In vitro fertilization pregnancies
3899 58 1.5
might be expected because these women were immediately advised to rest. This difference did not reach significance. The percentage of women presenting with hypertension requiring treatment in the third trimester was higher in the in vitro fertilization group (p < O.OS). Similarly we noted an increase in first-trimester bleeding in patients after induction of ovulation (NS). Deliveries (Table V). The percentage of premature deliveries (6.3) was the same as in the control population (3.7). Paradoxically the highest proportion of premature deliveries was seen among the in vivo pregnancies after induction of ovulation. The percentage of cesarean sections increased from IS.S% in the control group to 21.S% in the in vivo pregnancies after induction of ovulation and to 48.6% in the in vitro pregnancies (p < 0.001). Elective procedures represented 40% of the cesarean sections in the in vitro fertilization group versus 32% in the pregnancies after induced ovulation and 41 % in the control group. Breech presentations were significantly more frequent in the in vitro pregnancies (13.9% versus 4.3% in the control group and S.6% among the induced ovulation pregnancies, p < 0.001). On the other hand the birth weights and the sex ratios were very similar in the three groups. Fifty-two of the 79 placentas were subjected to histopathologic examination but no abnormalities were demonstrated. Among the 79 singleton pregnancies there was one unexplained intrauterine death at term.
12.2
163 21 12.8
8 72.7
10 47.6
90 II
26 44.8
Induced ovulation pregnancies
This involved a macrosomic infant (weight of 4700 gm and 61 em in length) whose mother had no relevant past history or premonitory signs and in whom the autopsy gave no explanation of the cause of death. Among the 78 living children one was subsequently discovered to have a small diaphragmatic hernia, which was successfully repaired. Twin pregnancies (n = 11) (Table VI). Twin gestations represented 11 of the 90 pregnancies for a frequency of 12.2%. The frequency of twins was 12.8% in the induced pregnancies and I.S% in the spontaneous pregnancies. The antenatal course of the in vitro twin pregnancies did not differ from that in those occurring after ovulation induction. The frequency of cesarean section in the in vitro fertilization group was increased compared to that in the other two groups but the difference was not significant. In all 11 cases the twins were dichorionic and diamniotic.
Comment An increased percentage of spontaneous abortions and biochemical pregnancies (34.S% of the pregnancies conceived in our unit) was found in all series. IO Is this increase due to the technique of in vitro fertilization? Candidates for in vitro fertilization are infertile women who are already more predisposed than other women to spontaneous abortions and ectopic pregnancies. The risk of spontaneous abortion was estimated to be 10%
554
Frydman et al.
to 15% in the normal population I I and 21.7% to 30.5% among infertile women, depending on the series. 12 Furthermore, all in vitro fertilization patients undergo ovarian stimulation and, while the frequency of spontaneous abortion after ovulation induction varies from one treatment regimen to another, it is always in the region of 20%.11 If we exclude the biochemical pregnancies (as they are usually undetected) from our study, the percentage of clinical spontaneous abortions was 22.5%, which is not very different from the aforementioned figures. Finally, Edmonds et al. 13 have shown that in 34% of ovulatory cycles serum hCG reveals the presence of an embryo during the luteal phase that is subsequently lost before the pregnancy has a chance to become clinically apparent. Most of the time it is possible to predict immediately that the pregnancy will not progress and will remain a biochemical one by means of the first two hCG assays.8 The percentage of ectopic pregnancies after in vitro fertilization, which reaches 11 % of pregnancies in some series,14 is cause for concern. The ectopic pregnancies are more likely to be due to eggs that are initially placed in the uterus and move up toward the tube rather than to the untoward placing of the egg in the tubal ostium. This interpretation is suggested by the occurrence of bilateral ectopic pregnancies after transfer of multiple embryosl5 and the association of intrauterine and extrauterine pregnancies. 16 Their prevention currently seems impossible because bilateral salpingectomy, which could not really be contemplated where sterility is of a nontubal origin, would not solve the problem. There would remain a risk of interstitial ectopic pregnancy or of rupture of the cornu of a scarred uterus if the interstitial portion of the tube were resected. The increase in the pregnancy rate with the number of embryos transferred is universally acknowledged but is subject to variable mathematical laws. 10, 17 On the other hand, the importance of the number of embryos transferred in relation to the progress of pregnancy has been discussed. The increased risk of abortion described by Edwards and Steptoe6is refuted by Muashers et al. 18 There is no consensus on the maximum number of embryos to be replaced. Some would replace up to six,18 but our position is to restrict replacement to three to limit the number of multiple pregnancies. The percentage of twin pregnancies in our program is 12%. Of the pregnancies resulting from the transfer of two or three embryos only 20% were twin pregnancies. The reason for this is probably that all embryos transferred are not of the same quality.18 Better control of embryo freezing '9 would permit a reduction in the number of embryos replaced and in the incidence of multiple pregnancy. Although the majority of twin pregnancies after in vitro fertilization are dizygotic ones due to mul-
March,I986 Am J Obstet Gynecol
tiple embryo transfer, some monozygotic pregnancies have been described. 20 The frequency of first-trimester bleeding in induced ovulation and in vitro pregnancies can perhaps be explained by early abortion from an undetected multiple pregnancy. However, this explanation does not take account the bleeding that often occurs after the transfer of a single embryo in pregnant women. The frequency of hypertension can perhaps be explained by the greater number of primigravid patients and the older maternal age in the in vitro fertilization group. Weight gain, however, did not differ between the groups. The increased frequency of toxemia sometimes reported in induced ovulation pregnancies has been confirmed only in the in vitro fertilization group. Intrauterine development is normal after ovulation induction with human menopausal gonadotropins or clomiphene citrate I but it has not been well studied after in vitro fertilization. 22 Fertile women often have an ambivalence between the desire for pregnancy and the desire for children. This invests in vitro fertilization with a special significance because an additional factor among infertile women is the pursuit of their female identity, which has been called into question by their sterility. We were surprised that in many cases women failed to follow the medical advice that was appropriate for this type of precious pregnancy.23 The occurrence of malformation appears rare; one cardiac malformation has been described 22 and a single trisomy 21 has been reported in the literature in 600 births!4 The fetal malformation rate after ovarian stimulation is usually accepted to be 1.8%, which is comparable to the rate observed in spontaneous pregnancy.25,26 Is the use of repeated ultrasound, for monitoring ovulation and more recently for the recovery of the oocyte, harmless? Desmoulin et al. 27 found a decrease in fertility in women having artificial insemination who underwent ultrasound monitoring when compared with those who did not. Puissant et al. 28 have shown that ultrasound treatment applied to mouse 00cytes before fertilization results in delayed deleterious effects; more resorptions occurred after implantation among the group originating from sonicated oocytes. However, initial results show that ultrasound-guided puncture has a normal ongoing pregnancy rate identical to that of laparoscopic recovery.3 We cannot explain the significant proportion of breech presentations. The only causal factor noted was the high frequency of primigravid patients and their age. It is not too surprising that a large proportion of deliveries were accomplished by cesarean section, and this phenomenon also occurs in other units 22 . 24 partly because of anxiety on the part of the obstetrician when faced with
Obstetric outcome of 100 IVF-ET births
Volume 154 Number 3
this rare situation but also perhaps because of the raised proportion of breech presentations. After ovarian stimulation a predominance of female infants has been reported on several occasions,29-31 but this has not been described in in vitro fertilization. In conclusion, the percentage of spontaneous abortions after in vitro fertilization is apparently raised only if one takes into account the population for which in vitro fertilization is intended and the ovulation induction treatments used. This raised percentage is explicable without calling into question the technique of in vitro fertilization itself. The occurrence of ectopic pregnancies after in vitro fertilization is no longer surprising. With the exception of maternal hypertension, there are no more complications of ongoing pregnancies after in vitro fertilization than there are after induced ovulation pregnancies or spontaneous pregnancies but the frequency of breech presentation is high. The considerable proportion of cesarean deliveries will undoubtedly lessen as in vitro fertilization pregnancies become more commonplace. We would like to express our sincere thanks to M. Chiesa and A. Richard for the obstetric results, to R. Forman for his translation, and to B. Lassalle, M. Volante, A. Gazengel, and V. Berthe for their technical assistance. REFERENCES 1. Edwards RG, Steptoe PC, Purdy jM. Establishing full term human pregnancies using cleaving embryos grown in vitro. Br j Obstet Gynaecol 1980;87:737-56. 2. Frydman R, Testart j, Lassalle B, Kerbrat G, Chasseray jE, Papiernik E. Transfert utt~rin d'un oeuf feconde in vitro: Avortement spontanee. N ouv Presse Med 1981; 10:3475-6. 3. Belaisch-Allart j, Hazout A, Guillet-Rosso F, Glissant M, Testart j, Frydman R. Various techniques for oocyte recovery in an IVF and ET programm. j Vitro Fertil Embryo Transf 1985;2:99-104. 4. Testartj, Lassalle B, Frydman R. Aparatus for the in vitro fertilization and culture of human oocytes. Fertil Steril 1982;38:372-5. 5. Roger M. Belaisch-Allart j, Del-POlO D, Feinstein MC, Frydman R, Testart J: Early detection of pregnancy and the concept of biochemical pregnancy after in vitro fertilization. Cargese, France: Elsevier. 6. Edwards RG, Steptoe P. Current status of in vitro fertilization and implantation of human embryos. Lancet 1983;1265-9. 7. jones H, Acosta A, Andrews R, et al. What is a pregnancy? A question for a program of in vitro fertilization. Fertil Steril 1983;6:728-33. 8. Belaisch-Allartj, RainhornjD, Guillet-Rosso F, et al. Valeur predictive du taux d'hCG dans les 15 premiers jours apres fecondation in vitro et transfert embryonnaire. Paris, France: 4eme Symposium Ste Franco-Allemande de Gynecologie et Obstetrique, April 26-29, 1984. 9. Frydman R, Testartj, Belaisch-Allartj, Lefevre B, Roger M, Boue J. Chromosomal and hormonal studies in preg-
10. II. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.
26.
27. 28. 29. 30. 31.
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nancies after in vitro fertilization. In; Feichtinger W, Kemeter P, eds. Recent program in human in vitro fertilization. Palermo: Cofese, 1984:241-2. Edwards RG, Fishel S, Cohen j, et al. Factors influencing the success of in vitro fertilization for alleviating human infertility. j Vitro Fertil Embryo Transf 1984; I :3-23. Boue A, Boue j. Le role des anomalies chromosomiques dans les echecs de la reproduction. j Gynecol Obstet Bioi Reprod 1977;6:5-21. Weir NC, Henricks CH. The reproductive capacity of an infertile population. Fertil Steril 1969;20:289-98. Edmonds K, Lindsay K, Miller j, Williamson E, Wood P. Early embryonic mortality in women, Fertil Steril 1982; 38:447-53. Lopata A. Concepts in human in vitro fertilization and embryo transfer. Fertil Steril 1983;40:289-30 I. Trotnow S, Al Hasani S, Hunlich T, Schill WB. Bilateral tubal pregnancy following in vitro fertilization and embryo transfer. Arch Gynecol 1983;234:75-8. Salat Baroux j, Giacomini P, Cornet D, et al. Caracteristiques des grossesses obtenues par fecondation in vitro. j Gynecol Obstet Bioi Reprod 1985;14:365-74. Speir AL, Lopata A, Gronon Mj, Kellow GN, johnston WL. Analysis of the benefits and risks of multiple embryo transfer. Fertil Steril 1983 ;39:468-71. Muashers C, Wilkes, Garcia j, Rosennacks SZ, jones H. Benefits and risks of multiple transfer with in vitro fertilisation. Lancet 1984; I :570. Trounson A, Mohr L. Human pregnancy following cryopreservation, thawing and transfer of an eight cell embryo. Nature 1983;305:305-7. Yovich j, Stanger j, Gravaug A, et al. Monozygotic twins from in vitro fertilization. Fertil Steril 1984;6:833-7. Hack M, Lunenfeld B. The influence of hormone induction of ovulation on the fetus and newborn. Pediatric and adolescent endocrinology. Basel; Karger, 1979:161-212. Wood C, Trounson A, Leetonj, et al. Clinical features of eight pregnancies resulting from in vitro fertilization and embryo transfer. Fertil Steril 1982;38:22-9. Raoul-Duval A, Frydman R. Fecondation in vitro: les hors la mere. Contrib Ferti! Sex 1983;2:281-5. Seppala M. The world collaborative report on in vitro fertilization and embryo replacement: current state of the art in january 1984. Ann NY Acad Sci 1985;442:558-63. Oelsner G, Gerr DM, Mashiach S, Blankstein j, Snyder M, Lunenfeld B. The study of induction of ovulation with menotropins: analysis of results of 1987 treatment cycles. Fertil Steril 1978;30:538-44. Schartz M,jewelewicz R, Dyrenfurth I, Tropper P, Vande Wiele RL. The use of human menopausal and chorionic gonadotropins for induction of ovulation. AM j OBSTET GYNECOL 1980;138:801-7. Desmoulin A, Shaaps jP, Bologne R, Lambotte R. Is ultrasound monitoring of follicular growth harmless. j Vitro Fertil Embryo Trans 1984; 1: 106. Puissant F, Lejeune F, Leroy F. Effects on mature mouse oocytes of ultrasound treatment applied before in vitro fertilization. IRCS Med Sci 1984;12:421-2. Barrat j, Leger D. Avenir des grossesses obtenues apres stimulation de l'ovulation. A propos de 519 grosseses. j Gynecol Obstet Bioi Reprod 1979;8:333-42. Caspi E, Rowen j, Schreyer P, Golberg M. The outcome of pregnancy after gonadotrophin therapy. Br j Obstet Gynaecol 1976;83:967-73. Sampson j, Alexander N, Fulgham D, Burry K. Gender after artifical induction of ovulation and artificial insemination. Ferti! Steril 1983;40:481-4.
6. O'Sullivan JB, Mahan CM. Criteria for the oral glucose tolerance test in pregnancy. Diabetes 1964; 13:278. 7. Carpenter MW, Coustan D. Criteria for screening tests for gestational diabetes. AM J OBSTET GYNECOL 1982; 144:768. 8. McNemar Q. Note on the sampling error of the difference between correlated proportions or percentages. Psychometrica 1947;12:153. 9. Pedersen J. The pregnant diabetic and her newborn. 2nd ed. Baltimore, Maryland: Williams & Wilkins, 1977:211. 10. O'SullivanJB, Mahan CM, Charles D, Dandrow RV. Med-
March, 1986 Am J Obstet Gynecol
ical treatment of the gestational diabetic. Obstet Gynecol 1974;43:817. II. Coustan DR, Lewis SB. Insulin therapy for gestational diabetes. Obstet Gynecol 1978;51 :306. 12. Roversi GD, Gargiulo M, Nicolini V, et al. Maximal tolerated insulin therapy in gestational diabetics. Diabetes Care 1980;3:489. 13. Metzger BE, Phelps R, Freinkel N. Predictive value of fasting plasma glucose in gestational diabetes mellitus. Diabetes 1981 ;30:4A.
An obstetric assessment of the first 100 births from the in vitro fertilization program at Clamart, France Rene Frydman, M.D., Joelle Belaisch-Allart, M.D., Nicolas Fries, M.D., Andre Hazout, M.D., Amelie Glissant, M.D., and Jacques Testart, Ph.D. Clamart, France From April, 1981, to July, 1984, 142 pregnancies have been attained after in vitro fertilization and embryo transfer. They are divided into 22 biochemical pregnancies (human chorionic gonadotropin ;;020 mU/ml but remaining below 1000 mU/ml), 27 spontaneous abortions, three ectopiC pregnancies, and 90 ongoing pregnancies, of which 11 were twin pregnancies. The 90 women in whom the pregnancies progressed were compared with the 52 women having non progressive pregnancies. The two populations did not differ either in age, in the indication for in vitro fertilization and embryo transfer, or in the quality of ovulation or results of semen analysis. The 90 ongoing pregnancies were compared with those pregnancies occurring in the same obstetrics department during this period. We found that the in vitro fertilization group had a higher proportion of arterial hypertension (16.5% versus 8.5%, p < 0.05), breech presentations (13.9% versus 4.3%, p < 0.001), and caesarean sections (46.8% versus 15.5%, p < 0.001) but the sex ratio did not differ. (AM J OasTET GVNECOL 1986;154:550-5.)
Key words: In vitro fertilization and embryo transfer, obstetric outcome
After the success of Edwards and Steptoe,! the procedure of in vitro fertilization and embryo transfer has become one of the possible treatments for certain types of infertility. More than 2000 children have been conceived by this method. Little information is available on the outcome of these pregnancies as the patients are not usually delivered in the in vitro fertilization center. At Clamart, the in vitro fertilization center is part of the obstetrics department and this enables us to follow up most of the pregnancies and to establish a register of both the pregnancies and the births for all patients. We present in this paper an assessment of the first 142 pregnancies. We have compared the spontaneous abor-
From the Department d'Obstetrique et Gynecologie (Pr. E. Papiernik), H6pital Antoine Beciere, and the Unite Institut National de la Sante et de La Recherche Medicale 187 (Pr. E. Papiernik). Received for publication August 23. 1985; accepted November 7. 1985. Reprint requests: R. Frydman, H6pital A. Beclere, 92141 Clamart, France.
550
tion rate, fetal growth, obstetric complications, and method of delivery in these pregnancies with those occurring after spontaneous pregnancies as well as after induction of ovulation.
Patients and methods From April, 1981, when the first in vitro pregnancy occurred-which ended as a spontaneous abortion 2to July, 1984, when the one hundredth baby was conceived, 1280 oocyte retrievals were performed for in vitro fertilization and 142 pregnancies commenced. All patients included in the in vitro fertilization program had a preliminary workup comprising an assessment of ovulation, a semen analysis, and an assessment of previous surgical procedures to decide whether they needed a laparoscopic examination. All 142 pregnancies occurred after ovulation induction. A combination of clomiphene citrate (Merrell Torraude, Paris, France) and human menopausal gonadotropins (Inductor, Searle, Paris, France) was used in 94% of the
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Volume 154 Number 3
Table I. Population analysis N onprogressive pregnancies
No. Age (yr) Sterility (%) Primary Secondary Indication for in vitro fertilization (%) Tubal sterility Immunologic Idiopathic Normal ovulation (%) Normal semen analysis (%)
90 32.1 ± 3.3
39 61
92 4.5
88 1.9 3.8 55.3 85.2
1.1
58.2 91.3
Table II. N umber of embryos transferred and the progress of the 142 pregnancies No. of embryos transferred
52 32.8 ± 3.9
44 56
cases. In all but four cases human chorionic gonadotropin (hCG) was given in lieu of the ovulatory surge and oocyte recovery took place 35 ± I hours afterward, either laparoscopically with the patient under general or local anaesthesia or with ultrasonographic guidance according to previously described techniques.' The details of ovulation monitoring and of in vitro culture techniques have been described elsewhere.'· 4 After embryo transfer the only treatment given was dydrogesterone (Duphaston, Duphar, Villeurbanne, France) in known cases of luteal insufficiency. Commencing on the eleventh day after oocyte aspiration (13 days after the administration of hCG) the serum levels of hCG were measured by radioimmunoassay every 2 days. The assays were repeated every 2 days until the twenty-third day, then weekly for the first 10 weeks of amenorrhea. Ultrasonography was performed around the eighth week of amenorrhea. We defined biochemical pregnancy by an hCG value ~20 mIU/ml on two occasions after the eleventh day following aspiration but never exceeding 1000 mIU/ml.' In fact when this last value was reached, a gestational sac was always detected by the ultrasound scan and the pregnancy had become clinical. Should the pregnancy I then not proceed, we termed it a spontaneous abortion. This classification of pregnancy is similar to that of Edwards and Steptoe6 but differs from that of Jones et al.,7 as we found that with the use of clomiphene and human menopausal gonadotropins, 50% of the luteal phases exceed 15 days in the absence of a pregnancy.' The 142 pregnancies were divided in the following way: A total of 90 pregnancies progressed to term, and among these there were 11 twin pregnancies and 79 singleton pregnancies resulting in 100 living babies and one intrauterine death. There were 22 biochemical pregnancies, and 27 pregnancies terminated as spontaneous abortions. Three ectopic pregnancies occurred during this period. First of all we have compared the ongoing pregnan-
551
1
Total No. transferred Ongoing pregnancies (% of all pregnancies) Twin pregnancies (% of ongoing pregnancies)
3
50 66
57 60
35 66
0
21
22
cies with those that failed to progress; then we have compared the in vitro pregnancies with those obtained after induction of ovulation as well as with all pregnancies with delivery at Antoine Beclere Hospital during the same period. We looked at the singleton and multiple pregnancies separately. Statistical method. Sample means were compared by means of Student's t tests and proportions compared by X2 analysis. Means are expressed together with the standard deviation.
Results Comparison between ongoing and non progressive in vitro pregnancies Population analysis (Table I). The proportion of patients with primary or secondary sterility and the indication for in vitro fertilization did not differ between the two groups. Ninety percent of patients in the program were candidates for in vitro fertilization on account of tubal sterility. Similarly the percentages with normal ovulation and normal results of semen analysis did not differ. Mean age of patients who aborted (32.8 years) was the same as that of those in whom pregnancy progressed (32.1 years). The proportions of laparoscopic oocyte recovery of ultrasonically guided puncture were the same in the two groups (81 % and 82% laparoscopic oocyte recovery). Biochemical pregnancies. The level of hCG remained below 300 mIU/ml in 20 of the 22 cases and between 300 and 1000 in two cases. In 18 cases the hCG threshold' appeared more than 13 days after follicular puncture and there was an inadequate rise from one measurement to the other. 8 The duration of the luteal phase had been prolonged from 0 to 15 days with a mean of 5 days. Spontaneous abortions. These occurred most often between the sixth and twelfth weeks of amenorrhea (25 cases). The explusion of the fetus was always delayed in relation to the fall in hCG, even necessitating an aspiration of the uterine cavity in five cases where the fetus had not been expelled 1 month after the pregnancy terminated. In the 27 cases, only six chromosomal analyses could be performed. Two were normal,
552
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March, 1986 Am J Obstet Gynecol
Table III. Analysis of the three preganancy groups (excluding twins)
No. Age (yr) Primigravid (%) No. of consultations Weight gain (kg)
Spontaneous (control) pregnancies
In vitro fertilization pregnancies
Induced ovulation pregnancies
3841 28.6 ± 4.2* 46.2* 6.9 ± 3.7* 12.8 ± 3.7
79 32.5 ± 3.5 83.5 8.3 ± 2.1 12.9 ± 3.6
142* 29.3 ± 4.2 57.8 6.8 ± 1.6 12.6 ± 3.6
Mean ± SD. *p < 0.001.
Table IV. Pregnancy complications (excluding twins) Spontaneous (control) pregnancies
No. First-trimester bleeding No. % All pregnancies Threatened premature delivery No. % All pregnancies Arterial hypertension No. % All pregnancies Fetal growth retardation No. % All pregnancies
In vitro fertilization pregnancies
Induced ovulation pregnancies
3841
79
142
374 9.7
12 15.2
19 13.4
420
6
10.9
7.6
23 16.2
327* 8.5
13 16.5
13 9.1
443 11.5
7
14.8
21 14.8
*p < 0.05.
one revealed a monosomy 45,X, and the other three showed trisomies 20, 22, and 15. Only two abortions were recorded later than 12 weeks, one in a twin pregnancy at 17 weeks and the other at 18 weeks associated with a pyrexia after amniocentesis. Ectopic pregnancies. Among the three ectopic pregnancies, two were easily diagnosed at 7 weeks of amenorrhea by ultrasound and the levels ofhCG. These were ampullary ectopic pregnancies in patients who had a past history of tubal surgical procedures and who were known to have hydrosalpinges. The third was a pregnancy implanted in the right uterine cornu in a woman who had previously undergone a right salpingectomy for an ectopic pregnancy. The diagnosis was made only at 10 weeks of amenorrhea when she presented with the signs of a hemoperitoneum. Number of embryos transferred (Table II). When a pregnancy occurred, whatever the number of embryos transferred, the percentage of ongoing pregnancies was around 60. The percentage of twin pregnancies was virtually the same whether two or three embryos were transferred (21 and 22). The 11 sets of twins developed from the transfer of two embryos in six cases and three embryos in five cases. Of the 27 abortions, two occurred in the course of a known twin pregnancy (after the transfer of two embryos in both cases). However, as the first ultrasound examination was requested
only after 8 weeks of amenorrhea, there must be a certain number of early twin pregnancies, of which we are unaware, that subsequently become singleton gestations. Comparison of the singleton in vitro ongoing pregnancies (n = 79) with the induced (n = 142) and control (n 3841) pregnancies Age, parity, and antenatal progress (Table III). The patients who had successful in vitro fertilization were older than the women with ind uction of labor and those with spontaneous pregnancies (p < 0.001). The proportion of primigravid women in the in vitro fertilization group was higher than in the other two groups (p < 0.001). The number of antenatal consultations was much greater in the in vitro fertilization patients but the weight gain was identical in all three groups. The first 10 patients who became pregnant after in vitro fertilization systematically underwent amniocentesis, but in the remainder only those patients in whom amniocentesis was justified on account of their age or past obstetric history were submitted to it. 9 Pregnancy complications (Table IV). We limited ourselves to studying bleeding in the first trimester, threatened premature delivery justifying hospitalization, fetal growth retardation, and hypertension requiring treatment. The percentage of threatened premature deliveries tended to be lower in the in vitro pregnancies, as
=
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553
Table V. Outcome of deliveries Spontaneous (control) pregnancies
No. Premature deliveries No. % All deliveries Cesarean sections No. % All deliveries Breech presentations No. % All deliveries Sex ratio Girls (%) Boys (%) Birth weight (gm)
In vitro fertilization pregnancies
3841
79
144
5
Induced ovulation pregnancies
142
3.7
6.3
13 9.1
597 15.5*
37 46.8*
31 21.8
166 4.3*
II
8 5.6
13.9*
46.9 53.1 3273 ::!: 490
55.7 44.3 3249 ::!: 460
46.5 53.5 3142 ::!: 557
*p < 0.001.
Table VI. Twin pregnancies Spontaneous (control) pregnancies
Total No. of pregnancies No. of twin pregnancies Frequency of twin pregnancy (%) Cesarean sections No. % All deliveries
In vitro fertilization pregnancies
3899 58 1.5
might be expected because these women were immediately advised to rest. This difference did not reach significance. The percentage of women presenting with hypertension requiring treatment in the third trimester was higher in the in vitro fertilization group (p < O.OS). Similarly we noted an increase in first-trimester bleeding in patients after induction of ovulation (NS). Deliveries (Table V). The percentage of premature deliveries (6.3) was the same as in the control population (3.7). Paradoxically the highest proportion of premature deliveries was seen among the in vivo pregnancies after induction of ovulation. The percentage of cesarean sections increased from IS.S% in the control group to 21.S% in the in vivo pregnancies after induction of ovulation and to 48.6% in the in vitro pregnancies (p < 0.001). Elective procedures represented 40% of the cesarean sections in the in vitro fertilization group versus 32% in the pregnancies after induced ovulation and 41 % in the control group. Breech presentations were significantly more frequent in the in vitro pregnancies (13.9% versus 4.3% in the control group and S.6% among the induced ovulation pregnancies, p < 0.001). On the other hand the birth weights and the sex ratios were very similar in the three groups. Fifty-two of the 79 placentas were subjected to histopathologic examination but no abnormalities were demonstrated. Among the 79 singleton pregnancies there was one unexplained intrauterine death at term.
12.2
163 21 12.8
8 72.7
10 47.6
90 II
26 44.8
Induced ovulation pregnancies
This involved a macrosomic infant (weight of 4700 gm and 61 em in length) whose mother had no relevant past history or premonitory signs and in whom the autopsy gave no explanation of the cause of death. Among the 78 living children one was subsequently discovered to have a small diaphragmatic hernia, which was successfully repaired. Twin pregnancies (n = 11) (Table VI). Twin gestations represented 11 of the 90 pregnancies for a frequency of 12.2%. The frequency of twins was 12.8% in the induced pregnancies and I.S% in the spontaneous pregnancies. The antenatal course of the in vitro twin pregnancies did not differ from that in those occurring after ovulation induction. The frequency of cesarean section in the in vitro fertilization group was increased compared to that in the other two groups but the difference was not significant. In all 11 cases the twins were dichorionic and diamniotic.
Comment An increased percentage of spontaneous abortions and biochemical pregnancies (34.S% of the pregnancies conceived in our unit) was found in all series. IO Is this increase due to the technique of in vitro fertilization? Candidates for in vitro fertilization are infertile women who are already more predisposed than other women to spontaneous abortions and ectopic pregnancies. The risk of spontaneous abortion was estimated to be 10%
554
Frydman et al.
to 15% in the normal population I I and 21.7% to 30.5% among infertile women, depending on the series. 12 Furthermore, all in vitro fertilization patients undergo ovarian stimulation and, while the frequency of spontaneous abortion after ovulation induction varies from one treatment regimen to another, it is always in the region of 20%.11 If we exclude the biochemical pregnancies (as they are usually undetected) from our study, the percentage of clinical spontaneous abortions was 22.5%, which is not very different from the aforementioned figures. Finally, Edmonds et al. 13 have shown that in 34% of ovulatory cycles serum hCG reveals the presence of an embryo during the luteal phase that is subsequently lost before the pregnancy has a chance to become clinically apparent. Most of the time it is possible to predict immediately that the pregnancy will not progress and will remain a biochemical one by means of the first two hCG assays.8 The percentage of ectopic pregnancies after in vitro fertilization, which reaches 11 % of pregnancies in some series,14 is cause for concern. The ectopic pregnancies are more likely to be due to eggs that are initially placed in the uterus and move up toward the tube rather than to the untoward placing of the egg in the tubal ostium. This interpretation is suggested by the occurrence of bilateral ectopic pregnancies after transfer of multiple embryosl5 and the association of intrauterine and extrauterine pregnancies. 16 Their prevention currently seems impossible because bilateral salpingectomy, which could not really be contemplated where sterility is of a nontubal origin, would not solve the problem. There would remain a risk of interstitial ectopic pregnancy or of rupture of the cornu of a scarred uterus if the interstitial portion of the tube were resected. The increase in the pregnancy rate with the number of embryos transferred is universally acknowledged but is subject to variable mathematical laws. 10, 17 On the other hand, the importance of the number of embryos transferred in relation to the progress of pregnancy has been discussed. The increased risk of abortion described by Edwards and Steptoe6is refuted by Muashers et al. 18 There is no consensus on the maximum number of embryos to be replaced. Some would replace up to six,18 but our position is to restrict replacement to three to limit the number of multiple pregnancies. The percentage of twin pregnancies in our program is 12%. Of the pregnancies resulting from the transfer of two or three embryos only 20% were twin pregnancies. The reason for this is probably that all embryos transferred are not of the same quality.18 Better control of embryo freezing '9 would permit a reduction in the number of embryos replaced and in the incidence of multiple pregnancy. Although the majority of twin pregnancies after in vitro fertilization are dizygotic ones due to mul-
March,I986 Am J Obstet Gynecol
tiple embryo transfer, some monozygotic pregnancies have been described. 20 The frequency of first-trimester bleeding in induced ovulation and in vitro pregnancies can perhaps be explained by early abortion from an undetected multiple pregnancy. However, this explanation does not take account the bleeding that often occurs after the transfer of a single embryo in pregnant women. The frequency of hypertension can perhaps be explained by the greater number of primigravid patients and the older maternal age in the in vitro fertilization group. Weight gain, however, did not differ between the groups. The increased frequency of toxemia sometimes reported in induced ovulation pregnancies has been confirmed only in the in vitro fertilization group. Intrauterine development is normal after ovulation induction with human menopausal gonadotropins or clomiphene citrate I but it has not been well studied after in vitro fertilization. 22 Fertile women often have an ambivalence between the desire for pregnancy and the desire for children. This invests in vitro fertilization with a special significance because an additional factor among infertile women is the pursuit of their female identity, which has been called into question by their sterility. We were surprised that in many cases women failed to follow the medical advice that was appropriate for this type of precious pregnancy.23 The occurrence of malformation appears rare; one cardiac malformation has been described 22 and a single trisomy 21 has been reported in the literature in 600 births!4 The fetal malformation rate after ovarian stimulation is usually accepted to be 1.8%, which is comparable to the rate observed in spontaneous pregnancy.25,26 Is the use of repeated ultrasound, for monitoring ovulation and more recently for the recovery of the oocyte, harmless? Desmoulin et al. 27 found a decrease in fertility in women having artificial insemination who underwent ultrasound monitoring when compared with those who did not. Puissant et al. 28 have shown that ultrasound treatment applied to mouse 00cytes before fertilization results in delayed deleterious effects; more resorptions occurred after implantation among the group originating from sonicated oocytes. However, initial results show that ultrasound-guided puncture has a normal ongoing pregnancy rate identical to that of laparoscopic recovery.3 We cannot explain the significant proportion of breech presentations. The only causal factor noted was the high frequency of primigravid patients and their age. It is not too surprising that a large proportion of deliveries were accomplished by cesarean section, and this phenomenon also occurs in other units 22 . 24 partly because of anxiety on the part of the obstetrician when faced with
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Volume 154 Number 3
this rare situation but also perhaps because of the raised proportion of breech presentations. After ovarian stimulation a predominance of female infants has been reported on several occasions,29-31 but this has not been described in in vitro fertilization. In conclusion, the percentage of spontaneous abortions after in vitro fertilization is apparently raised only if one takes into account the population for which in vitro fertilization is intended and the ovulation induction treatments used. This raised percentage is explicable without calling into question the technique of in vitro fertilization itself. The occurrence of ectopic pregnancies after in vitro fertilization is no longer surprising. With the exception of maternal hypertension, there are no more complications of ongoing pregnancies after in vitro fertilization than there are after induced ovulation pregnancies or spontaneous pregnancies but the frequency of breech presentation is high. The considerable proportion of cesarean deliveries will undoubtedly lessen as in vitro fertilization pregnancies become more commonplace. We would like to express our sincere thanks to M. Chiesa and A. Richard for the obstetric results, to R. Forman for his translation, and to B. Lassalle, M. Volante, A. Gazengel, and V. Berthe for their technical assistance. REFERENCES 1. Edwards RG, Steptoe PC, Purdy jM. Establishing full term human pregnancies using cleaving embryos grown in vitro. Br j Obstet Gynaecol 1980;87:737-56. 2. Frydman R, Testart j, Lassalle B, Kerbrat G, Chasseray jE, Papiernik E. Transfert utt~rin d'un oeuf feconde in vitro: Avortement spontanee. N ouv Presse Med 1981; 10:3475-6. 3. Belaisch-Allart j, Hazout A, Guillet-Rosso F, Glissant M, Testart j, Frydman R. Various techniques for oocyte recovery in an IVF and ET programm. j Vitro Fertil Embryo Transf 1985;2:99-104. 4. Testartj, Lassalle B, Frydman R. Aparatus for the in vitro fertilization and culture of human oocytes. Fertil Steril 1982;38:372-5. 5. Roger M. Belaisch-Allart j, Del-POlO D, Feinstein MC, Frydman R, Testart J: Early detection of pregnancy and the concept of biochemical pregnancy after in vitro fertilization. Cargese, France: Elsevier. 6. Edwards RG, Steptoe P. Current status of in vitro fertilization and implantation of human embryos. Lancet 1983;1265-9. 7. jones H, Acosta A, Andrews R, et al. What is a pregnancy? A question for a program of in vitro fertilization. Fertil Steril 1983;6:728-33. 8. Belaisch-Allartj, RainhornjD, Guillet-Rosso F, et al. Valeur predictive du taux d'hCG dans les 15 premiers jours apres fecondation in vitro et transfert embryonnaire. Paris, France: 4eme Symposium Ste Franco-Allemande de Gynecologie et Obstetrique, April 26-29, 1984. 9. Frydman R, Testartj, Belaisch-Allartj, Lefevre B, Roger M, Boue J. Chromosomal and hormonal studies in preg-
10. II. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25.
26.
27. 28. 29. 30. 31.
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nancies after in vitro fertilization. In; Feichtinger W, Kemeter P, eds. Recent program in human in vitro fertilization. Palermo: Cofese, 1984:241-2. Edwards RG, Fishel S, Cohen j, et al. Factors influencing the success of in vitro fertilization for alleviating human infertility. j Vitro Fertil Embryo Transf 1984; I :3-23. Boue A, Boue j. Le role des anomalies chromosomiques dans les echecs de la reproduction. j Gynecol Obstet Bioi Reprod 1977;6:5-21. Weir NC, Henricks CH. The reproductive capacity of an infertile population. Fertil Steril 1969;20:289-98. Edmonds K, Lindsay K, Miller j, Williamson E, Wood P. Early embryonic mortality in women, Fertil Steril 1982; 38:447-53. Lopata A. Concepts in human in vitro fertilization and embryo transfer. Fertil Steril 1983;40:289-30 I. Trotnow S, Al Hasani S, Hunlich T, Schill WB. Bilateral tubal pregnancy following in vitro fertilization and embryo transfer. Arch Gynecol 1983;234:75-8. Salat Baroux j, Giacomini P, Cornet D, et al. Caracteristiques des grossesses obtenues par fecondation in vitro. j Gynecol Obstet Bioi Reprod 1985;14:365-74. Speir AL, Lopata A, Gronon Mj, Kellow GN, johnston WL. Analysis of the benefits and risks of multiple embryo transfer. Fertil Steril 1983 ;39:468-71. Muashers C, Wilkes, Garcia j, Rosennacks SZ, jones H. Benefits and risks of multiple transfer with in vitro fertilisation. Lancet 1984; I :570. Trounson A, Mohr L. Human pregnancy following cryopreservation, thawing and transfer of an eight cell embryo. Nature 1983;305:305-7. Yovich j, Stanger j, Gravaug A, et al. Monozygotic twins from in vitro fertilization. Fertil Steril 1984;6:833-7. Hack M, Lunenfeld B. The influence of hormone induction of ovulation on the fetus and newborn. Pediatric and adolescent endocrinology. Basel; Karger, 1979:161-212. Wood C, Trounson A, Leetonj, et al. Clinical features of eight pregnancies resulting from in vitro fertilization and embryo transfer. Fertil Steril 1982;38:22-9. Raoul-Duval A, Frydman R. Fecondation in vitro: les hors la mere. Contrib Ferti! Sex 1983;2:281-5. Seppala M. The world collaborative report on in vitro fertilization and embryo replacement: current state of the art in january 1984. Ann NY Acad Sci 1985;442:558-63. Oelsner G, Gerr DM, Mashiach S, Blankstein j, Snyder M, Lunenfeld B. The study of induction of ovulation with menotropins: analysis of results of 1987 treatment cycles. Fertil Steril 1978;30:538-44. Schartz M,jewelewicz R, Dyrenfurth I, Tropper P, Vande Wiele RL. The use of human menopausal and chorionic gonadotropins for induction of ovulation. AM j OBSTET GYNECOL 1980;138:801-7. Desmoulin A, Shaaps jP, Bologne R, Lambotte R. Is ultrasound monitoring of follicular growth harmless. j Vitro Fertil Embryo Trans 1984; 1: 106. Puissant F, Lejeune F, Leroy F. Effects on mature mouse oocytes of ultrasound treatment applied before in vitro fertilization. IRCS Med Sci 1984;12:421-2. Barrat j, Leger D. Avenir des grossesses obtenues apres stimulation de l'ovulation. A propos de 519 grosseses. j Gynecol Obstet Bioi Reprod 1979;8:333-42. Caspi E, Rowen j, Schreyer P, Golberg M. The outcome of pregnancy after gonadotrophin therapy. Br j Obstet Gynaecol 1976;83:967-73. Sampson j, Alexander N, Fulgham D, Burry K. Gender after artifical induction of ovulation and artificial insemination. Ferti! Steril 1983;40:481-4.