Success of in vitro fertilization and embryo transfer in relation to the causes of infertility

In 1984 163 patients were treated in our in vitro fertilization program, including 4 patients accepting embryos from the oocyte and embryo donation program. Twenty pregnancies were achieved with an average chance per transfer of 16,6%. The final success of IVF strongly depends on the cause of infertility. The best results were obtained for patients with tubal infertility, with a pregnancy rate of 15% per laparoscopy and 19% per transfer. There is a significant decrease in oocyte cleavage rate from tubal (61%) to male infertility (13%). Once the barrier of embryo formation is taken, there is no marked difference in the mean number of embryos transferred on the pregnancy rate after transfer, among the different patient groups. In patients with tubal infertility the pregnancy rate per cycle remains constant, resulting in a cumulative pregnancy rate of 40% after 3 cycles.     

Different implantation rates after transfers of cryopreserved embryos originating from donated oocytes or from regular in vitro fertilization

Most oocyte donation programs have experienced higher pregnancy rates than usually seen in regular in vitro fertilization (IVF), suggesting that the quality of either the oocytes or the endometrium is superior. To clarify this issue we analyzed the results of transfers of 136 cryopreserved embryos originating either from donated oocytes (18 transfers) or from regular IVF (118 transfers). Transfers of embryos originating from donated oocytes took place after administrating oral estradiol (E2) valerate and vaginal micronized progesterone (P) following a regimen designed to mimic the serum levels of E2 and P observed during the menstrual cycle. Transfers of embryos originating from regular IVF took place either in the natural cycle (53 transfers) or after suppressing ovarian function with a single injection of a gonadotropin-releasing hormone agonist (GnRH-a), Decapeptyl-Retard 3.75 mg, and administering the same hormone replacement regimen (E2/P) used in oocyte donation (65 transfers). Eighteen transfers involving 24 embryos originating from donated oocytes were affected, resulting in six pregnancies (4 ongoing). The ongoing pregnancy rate per transfer was 22%. Seventy-nine embryos originating from regular IVF were transferred (53 transfers) in the natural cycle resulting in six pregnancies (2 ongoing). One hundred three other embryos originating from regular IVF were transferred (65 transfers) after administration of GnRH-a and E2/P resulting in four pregnancies. The pregnancy rate after transfers of embryos originating from regular IVF was 9% per transfer. This was significantly less than the pregnancy rate of 33% per transfer seen after the transfers of embryos originating from donated oocytes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrasonically guided oocyte collection under local anesthesia: the first choice method for in vitro fertilization--a comparative study with laparoscopy

Ultrasonically guided oocyte collection gradually replaces laparoscopy in many in vitro fertilization (IVF) centers. In the present study we compare the efficacy of both methods in our IVF program. One hundred twenty patients were prospectively randomized into two groups. Sixty women underwent oocyte collection during laparoscopy under general anesthesia, and 60 women under ultrasound guidance with local anesthesia. Superovulation was induced with human menopausal gonadotropin/human chorionic gonadotropin. For the oocyte collection a cannula with a trocar was used for single percutaneous puncture, through which both ovaries could be reached by the aspiration needle. The number of aspirated oocytes and transferred embryos was higher in the laparoscopy group as compared with the ultrasound group (5.3 versus 4.0 per woman and 3.0 versus 2.3 per woman, respectively); but the clinical pregnancy rate per cycle was similar in both groups (12.5% versus 14.5%). Ultrasound aspiration seems to be as effective as laparoscopy in terms of oocyte retrieval and conception rates. Because the procedure is simple and inexpensive, we believe that it may replace laparoscopy as a method for oocyte collection in most patients who undergo IVF.     

Evidence-based clinical outcome of oocyte slow cooling

In the last few years, there has been a significant improvement in oocyte cryopreservation techniques. To investigate the clinical significance of oocyte freezing, an assessment of the cumulative pregnancy rate per started cycle derived from the use of fresh and frozen-thawed oocytes was performed. Between 2004 and 2006, 749 cycles were carried out, in which no more than three fresh oocytes were inseminated either by standard IVF or microinjection. Supernumerary mature oocytes were cryopreserved by slow cooling. Cryopreservation of fresh embryos was performed in rare cases to prevent the risk of ovarian hyperstimulation syndrome using a standard embryo freezing protocol. Fresh embryo transfer cycles totalled 680, 257 of which resulted in pregnancy. The pregnancy rates per patient and per transfer were 34.3% and 37.8% respectively. When frozen-thawed oocytes were used, following 660 thawing cycles, 590 embryo transfers were performed in 510 patients. Eighty-eight pregnancies were achieved with embryos from frozen oocytes, with a success rate of 17.2% per cycle. When fresh and frozen-thawed cycles were combined, the number of pregnancies was 355, giving a cumulative pregnancy rate of 47.4%. Oocyte cryopreservation can contribute considerably to the overall clinical success, ensuring a cumulative rate approaching that achievable with embryo storage.     

The successful use of hatched blastocysts in assisted reproductive technology

This retrospective study was undertaken to determine the value of blastocyst culture and transfer as a tool in assisted reproductive technology. Six hundred and fifty-five cycles in patients undergoing IVF treatment for infertility were involved. All patients were aged < 40 years. Day-2 embryos were transferred to 427 (group 1) and day-6 embryos (blastocysts) were transferred to 228 patients (group 2). Pronucleate oocytes obtained from IVF were cultured in vitro for 2 or 6 days. One to five embryos were transferred. A total of 10,146 oocytes were retrieved, 6,105 oocytes were fertilized, 2,222 embryos were transferred and 197 clinical pregnancies were achieved in all groups. Blastocystes were transferred to almost 90% of group 2 patients. The pregnancy rate per cycle and implantation rate per transferred embryo was 42.1% and 19.4%, respectively, in the blastocyst group compared to 23.6% and 8.6%, respectively, when embryos were transferred on day 2. Even though in the blastocyst group there was an increased number of oocytes fertilized at the same time there was a significant reduction in the number of embryos being replaced (3.2 vs 3.8). This study demonstrate that transfer of blastocysts increases the success of IVF when compared with day-2 transfers and reduces the number of embryos to be transferred.     

Human in vitro fertilization employing individualized ovulation induction by human menopausal gonadotropins

One hundred six women suffering from obstructive tubal disease not corrected by previous surgery were treated in an in vitro fertilization (IVF) program. Ovulation was induced by 3 amps of human menopausal gonadotropin (HMG)/day starting on the third day of the cycle for 5 days. In most of the patients the regmmen was continued for another 1–3 days, depending on the individual's ovarian response (means, 20±5 amps/cycle). Monitoring consisted of daily follicular ultrasonography and serum estradiol measurements. Human chorionic gonadotropin (HCG), 10,000 IU, was administered when more than two large (1.5 to 1.8 cm in diameter) follicles were visualized. Using this regimen, a mean of five follicles per woman was aspirated, from which a mean of 3.9 over was recovered. The oocytes were pre-incuted for 8 or 24 hr. according to the morphological degree of inucification and dispersal of the oocyte-corona-cumulus complex. Following exposure to washed spermatozoa for 16 hr, a 68% fertilization rate was obtained. Oocytes were transferred into the uterus 48 hr after laparoscopy. Ninety-nine transfers (93% of the women) of 1–8 embryos (mean, 2.9/woman) were performed and resulted in 16 clinical pregnancies. No pregnancies occurred in 14 women transferred with one to three oocytes in the pronuclear stage and only one pregnancy (7.1%) was obtained in 14 women transferred with one cleaved oocyte. Over 70% of the women were transferred with two or more cleaved oocytes: in this group the pregnancyl transfer rate was 21%. Of thee pregnant women 5 of 16 (31%) aborted between 6 and 10 weeks of gestation and 1 (6%) had an ectopic pregnancy. The individualized regimen of HMG is valuable in increasing the number of fertilized oocytes and compensates with multiple-embryo transfers for the high early embryonic loss occurring in IVF.     

The combination of follicle-stimulating hormone and human menopausal gonadotropin for the induction of multiple follicular maturation for in vitro fertilization

One hundred fifty-one cycles in 134 consecutive patients were stimulated with 150 IU of human urinary follicle-stimulating hormone (FSH) and 150 IU of human menopausal gonadotropin (hMG) on cycle days 3 and 4 and then with 150 IU of hMG daily for the purpose of multiple follicular development for in vitro fertilization (IVF). Seventy-three patients did not have a prior IVF attempt, and 61 patients in 78 cycles had prior IVF attempts at least once with their previous cycles stimulated with the same method and/or hMG and/or FSH. There was an average of three preovulatory oocytes retrieved per laparoscopy and a pregnancy rate of 27% per transfer cycle. The results were equally favorable in "new" and "old" patient cycles. The pregnancy rate increased with the transfer of two or more conceptuses of preovulatory origin. The multiple pregnancy rate, but not the abortion rate, increased with increased numbers of conceptuses transferred.     

A prospective study comparing the outcome of oocytes retrieved in the aspirate with those retrieved in the flush during transvaginal ultrasound directed oocyte recovery for in-vitro fertilization.

OBJECTIVE: To study prospectively the fate of oocytes collected from the follicular aspirate and subsequent flushes during transvaginal ultrasound directed oocyte recovery for in-vitro fertilization (IVF). SETTING: A tertiary referral assisted conception centre. SUBJECTS: 100 consecutive patients undergoing 100 cycles of IVF. Four patients were withdrawn because their embryos were electively cryopreserved. Therefore 96 cycles were studied. MAIN OUTCOME MEASURES: The oocyte recovery rate, viability, fertilization and cleavage rates and outcome of embryos generated from oocytes that were obtained from either the initial aspirate (A1), dead space in the collecting system (A2) or the first two 2 ml flushes (F1 and F2) were compared. RESULTS: The overall oocyte recovery rate was 87.8%. Of the 1046 oocytes collected, 40.3% were from A1, 41.3% from A2, 13.7% from F1 and 4.7% from F2. There were comparable numbers of viable and fertilized oocytes and cleaved, transferred and frozen embryos in tubes A1 and A2 but all these parameters were significantly lower in tubes F1 and F2 (P < 0.0001). All these parameters were also significantly higher in F1 compared with F2 (P < 0.001), except for the number of embryos frozen, in which there was no difference. The overall pregnancy rate per cycle was 28.1% and the pregnancy rate per embryo transfer was 31.0%. There were no pregnancies in any of the cycles in which embryos originating from F2 were transferred, nor were there pregnancies in cycles in which only embryos from F1 were transferred. CONCLUSION: Follicular aspiration together with one 2 ml flush maximises the recovery of oocytes that will result in pregnancies.     

Improvement of IVF outcome in poor responders by discontinuation of GnRH analogue during the gonadotropin stimulation phase--a function of improved embryo quality.

PURPOSE: To assess the efficacy of a protocol involving the discontinuation of the GnRH analogue at the mid-phase of ovarian stimulation for IVF in patients with a previous poor response. METHODS: Prospective case-control evaluation compared with same patient's previous performance. Thirty-six patients enrolled in an IVF program were treated in two consecutive cycles. The first with a standardized protocol utilizing midluteal administration of Nafarelin (N) 600 mcg/d continued throughout the stimulation phase with human menopausal gonadotropin (hMG) until follicles of 20 mm were identified by transvaginal ultrasound (Standard group). Patients with a poor response in the Standard cycle were treated in the subsequent cycle with N and hMG initially in a similar manner, then N was stopped after 5 days of hMG stimulation (N-stop group). All clinical and laboratory aspects of treatment were done in a similar fashion in both cycles, each patient acting as her own control. RESULTS: Results were analyzed by paired t test. The change in each parameter in the N-stop cycle was expressed as the percent change as compared with the standard protocol cycle for each patient. Peak estradiol (E2) and number of aspirated oocytes were increased in the N-stop cycle (+16.9% and +28%, respectively), but insignificantly so. The percent of cleaving embryos was significantly increased by 27.9% (p = 0.03) in the N-stop cycle, as embryo morphology was improved by 22% (p = 0.02). The efficacy of gonadotropin treatment was enhanced in the N-stop cycle, as expressed by a 32.5% increase in oocytes retrieved per hMG ampoule administered (p = 0.04). Three cycles of 36 were cancelled during the N-stop cycle, whereas only one was cancelled in the standard protocol cycle. Of the 36 patients, 7 conceived in the N-stop protocol and 5 are ongoing pregnancies. CONCLUSION: Discontinuation of GnRH-a during ovarian stimulation for IVF has a beneficial, but not statistically significant, effect on both E2 and oocyte production. Embryo cleavage rates and morphology were significantly improved, this may be due to improved oocyte quality, which may have been responsible for achieving pregnancies. The efficacy of gonadotropin treatment was enhanced when GnRH-a was discontinued. These results hint that GnRH-a may have a direct negative effect on folliculogenesis and oocytes, which is apparent especially in poor responder patients.     

CLINICAL ASSISTED REPRODUCTION: Improvement of IVF Outcome in Poor Responders by Discontinuation of GnRH Analogue During the Gonadotropin Stimulation Phase—A Function of Improved Embryo Quality

Purpose: To assess the efficacy of a protocol involving the discontinuation of the GnRH analogue at the mid-phase of ovarian stimulation for IVF in patients with a previous poor response.Methods: Prospective case-control evaluation compared with same patient's previous performance. Thirty-six patients enrolled in an IVF program were treated in two consecutive cycles. The first with a standardized protocol utilizing mid-luteal administration of Nafarelin (N) 600 mcg/d continued throughout the stimulation phase with human menopausal gonadotropin (hMG) until follicles of 20 mm were identified by transvaginal ultrasound (Standard group). Patients with a poor response in the Standard cycle were treated in the subsequent cycle with N and hMG initially in a similar manner, then N was stopped after 5 days of hMG stimulation (N-stop group). All clinical and laboratory aspects of treatment were done in a similar fashion in both cycles, each patient acting as her own control.Results: Results were analyzed by paired t test. The change in each parameter in the N-stop cycle was expressed as the percent change as compared with the standard protocol cycle for each patient. Peak estradiol (E2) and number of aspirated oocytes were increased in the N-stop cycle (+16.9% and +28%, respectively), but insignificantly so. The percent of cleaving embryos was significantly increased by 27.9% (p = 0.03) in the N-stop cycle, as embryo morphology was improved by 22% (p = 0.02). The efficacy of gonadotropin treatment was enhanced in the N-stop cycle, as expressed by a 32.5% increase in oocytes retrieved per hMG ampoule administered (p = 0.04). Three cycles of 36 were cancelled during the N-stop cycle, whereas only one was cancelled in the standard protocol cycle. Of the 36 patients, 7 conceived in the N-stop protocol and 5 are ongoing pregnancies.Conclusion: Discontinuation of GnRH-a during ovarian stimulation for IVF has a beneficial, but not statistically significant, effect on both E2 and oocyte production. Embryo cleavage rates and morphology were significantly improved, this may be due to improved oocyte quality, which may have been responsible for achieving pregnancies. The efficacy of gonadotropin treatment was enhanced when GnRH-a was discontinued. These results hint that GnRH-a may have a direct negative effect on folliculogenesis and oocytes, which is apparent especially in poor responder patients.     

High pregnancy rate after early human embryo freezing

Human embryos produced by in vitro fertilization (IVF) were frozen with 1,2-propanediol as a cryoprotectant. Embryo survival after thawing was related to the presence of a nucleus in frozen cells and decreased with the increasing number of cells in the frozen embryo. None of five embryos frozen 3 or 4 days after IVF survived when thawed. Of 48 early embryos (35 patients) frozen 1 or 2 days after IVF, 42 (87.5%) were transferred in 32 patients. Ten pregnancies were initiated after frozen embryo transfer (ET). If we exclude the three infertile patients who had sexual intercourse in the fertile period, the pregnancy rate for each patient who had 1- or 2-day frozen embryo(s) was 22% (7 of 32). One of the pregnancies was obtained after ET of a 1-cell pronucleated frozen and thawed embryo. The rate of ongoing pregnancies after triple fresh ET was 23%. In patients having four embryos obtained in a single IVF cycle, the expected overall liveborn rate in an IVF-ET program including embryo cryopreservation could theoretically equal that of natural human fertility.     

A preliminary study on in vitro fertilization and embryo transfer

Forty-two women with infertility were enrolled in an in vitro fertilization and embryo transfer (IVF/ET) program, from July, 1986 to February, 1988, at the First Affiliated Hospital, Human Medical University. CC/hMG/hCG and hMG/hCG regimens for ovulation induction were used for 35 and 7 patients. Monitoring methods consisted of daily follicular ultrasonography and serum estradiol measurements. Human chorionic gonadotropin 10,000IU was administered when the leading follicle reached 18mm in diameter and serum E2 level was equal to or more than 1,480 pmol/L (400 pg/ml). Twenty-one laparoscopies and nineteen laparotomies for oocyte retrieval were performed. The IVF/ET results using CC/hMG/hCG for ovarian stimulation were as follows: an average of 6.1 follicles were aspirated and 3.5 oocytes recovered for one case. The recovery rate and fertilization rate was 57.0% and 60.1% respectively. In twenty-five women one to five embryos were transferred and a clinical pregnancy occurred in one who received three embryos. Laparotomy for oocyte retrieval showed that more oocytes could be obtained than laparoscopy. The purity of CO2 used for laparoscopy was considered to affect the IVF results.     

Single-embryo transfer: Rennes' Hospital experience

In 2005-2006, 905 punctures of oocytes were realised in the Assisted Reproductive Technology Centre of Rennes' Hospital in France, the source of 173 pregnancies after fresh embryos transfers and 185 pregnancies after frozen embryos transfers. The single-embryo transfer (SET) was proposed in all patients aged less than 38 years with at least two embryos type I or II on the first two cycles. Sixty-three percent of patients (n=293 cycles) chose the SET with 21.5% pregnancies through fresh embryo transfer. The SET with frozen embryos has been completed on 708 cycles with 16.8% of pregnancies per transfer. The cumulative rate of pregnancies by puncture is 39% and the overall risk of multiple pregnancies has dropped to 12%. The SET associated with an effective embryo cryopreservation therefore allows to reduce the risk of multiple births while maintaining a satisfactory pregnancy cumulative rate.     

Dose of human menopausal gonadotropin influences the outcome of an in vitro fertilization program

This study compares outcomes of in vitro fertilization (IVF) in two groups of 57 patients when either 2 (group 1) or 3 (group 2) ampules of human menopausal gonadotropin (hMG) were administered daily. Treatment began on day 3 of the cycle and was discontinued when at least 2 follicles attained diameters greater than or equal to 1.5 cm. Human chorionic gonadotropin (hCG) was given either 24 or 48 hours after the last dose of hMG. Although serum estradiol levels were lower in group 1, the average number of oocytes retrieved (3.2 versus 2.9), fertilized (1.9 versus 2.0), and cleaved (1.7 versus 1.8) per completed cycle did not differ between groups 1 and 2. Likewise, the number of oocytes that fertilized abnormally was similar in both groups (0.5 versus 0.3/cycle). However, the number of atretic oocytes (0.03 versus 0.5/cycle) and the percent of oocytes recovered from the cul-de-sac (0 versus 7.2%) were significantly (P less than 0.05) lower in group 1. In group 1, administration of hCG 48 hours after the last dose of hMG was associated with a higher number of cleaving embryos (2.1 versus 1.5/cycle) and a higher pregnancy rate (34.8 versus 14.7%; P less than 0.05) when compared with injection at 24 hours. In group 2, the interval between hMG and hCG did not influence these results. Together, the associations between fewer oocytes that were atretic or recovered from the cul-de-sac, and a trend toward a higher pregnancy rate, suggest that follicular recruitment with 2 ampules of hMG is more appropriate than 3 ampules in an IVF program.     

Improved pregnancy rate after transfer of embryos grown in human fallopian tubal cell coculture.

OBJECTIVE: To evaluate the embryonic behavior in vitro and the pregnancy and implantation rates of embryos grown in a human ampullary cell coculture system. DESIGN: In a prospective study, two pronuclei embryos were cultured on human ampullary feeder layers up to the two to six-cell and blastocyst stages and replaced either as tubal, uterine, or sequential transfers. SETTING: Assisted reproductive technology program in a university-based hospital. PATIENTS: Fifty women with a mean age of 35.6 years who went through a single coculture cycle. Thirty of the patients were admitted for in vitro fertilization (IVF) and 20 for tubal embryo transfer (TET). RESULTS: The overall clinical pregnancy rate (PR) for all 50 patients was 44% per cycle (IVF, 37%; TET, 55%) and the implantation rate was 31.8% (IVF, 31.0%; TET, 32.6%). Sixty-eight percent of pregnant patients were over 35 years, and 68% had two previously failed assisted reproduction cycles. Five of 9 patients who received sequential transfers became pregnant. Three of the 22 pregnancies aborted (2 after sequential transfer), and there was one ectopic. Overall, 88% of two to six-cell stage embryos were of good quality. CONCLUSIONS: The human ampullary coculture system produces better quality embryos, increased numbers of blastocysts with improved PRs and implantation rates. The beneficial effects of the feeder layer may be through the release of embryotrophic factors and detoxification of the medium by the cells. Coculture is a new concept in assisted reproduction and has tremendous potential in boosting conception rates by mimicking the in vivo environment.     

Oocyte retrieval in an IVF program. A comparison of laparoscopic and transvaginal ultrasound-guided follicular puncture

From 1 April 1986 to 20 May 1987, 160 oocyte retrievals were performed in our IVF program. 80 oocyte retrievals were done by laparoscopy under general anaesthesia and 80 under light sedation and local analgesia using transvaginal ultrasound guided follicle puncture. More oocytes were recovered with the ultrasound procedure than with laparoscopy, 616 versus 478. The fertilization rate was higher when the oocytes were collected with the ultrasound procedure, vis-à-vis laparoscopy, 70.6% versus 59.6%. The number of embryos transferred was greater in the former than in the latter group, 300 versus 182. There were 13 clinical pregnancies in the laparoscopy group versus 17 in the ultrasound group. There were no serious complications in either group. Transvaginal ultrasound guided follicle aspiration is a safe and simple procedure.     

Outcome of laser-assisted polar body biopsy and aneuploidy testing

Polar body biopsy and subsequent fluorescence in-situ hybridization (FISH) analysis allows detection of maternally derived chromosomal aneuploidies in human oocytes during IVF treatment. The development of a diode laser technique for the partial opening of the zona pellucida has stimulated the use of this technique to assist polar body biopsy. Laser-assisted polar body biopsy was performed in 140 IVF cycles from patients of advanced maternal age (> or =35 years). A total of 921 oocytes were treated by a laser for partial zona opening and polar body removal. FISH was performed for chromosomes 13, 16, 18, 21 and 22 and results were available for 903 oocytes (98%). In all, 443 oocytes (49.1%) were euploid and of these, 293 were fertilized. A total of 214 embryos were transferred in 120 embryo transfer cycles (1.78 per embryo transfer) resulting in 27 clinical pregnancies (22.5% per embryo transfer) with an implantation rate of 15.4%. Subsequently, five women aborted (18.5%) and 24 healthy children were born from the remaining 22 pregnancies, which gives a take home baby rate of 18.3% per transfer cycle. It is concluded that polar body biopsy using a diode laser system is as efficient as standard polar body biopsy using zona drilling.     

Various techniques for oocyte recovery in an in vitro fertilization and embryo transfer program

Oocyte recovery in an in vitro fertilization and embryo transfer (IVF-ET) program can be performed by laparoscopy or by sonography. Most IVF teams use either one or the other of these methods. In Clamart, we undertook 407 IVF attempts from September 1983 to March 1984, 225 by laparoscopy under general anesthesia, 97 by laparoscopy under local anesthesia, and 85 by sonography. Excluding the recovery techniques, all aspects of the program (ovulation monitoring, culture, and transfer) were identical in order to study the effects of the anesthesia and the ultrasound. We did not find any significant difference in pregnancy rates, inclusive of biochemical pregnancies, among these three recovery methods, although ultrasonically guided puncture gave fewer follicles, oocytes, and embryos than laparoscopy.     

反义寡核苷酸对激素敏感型单纯性肾病患儿外周血单个核细胞病毒基因表达的抑制作用

目的通过设计反义寡核苷酸(ASONs)抑制激素敏感型单纯性肾病(SRSNS)呼吸道病毒基因的表达，提供激素敏感型单纯性肾病呼吸道病毒感染的证据。 方法将ASONs转染至外周血单个核细胞(PBMC)后，通过RT PCR的方法检测呼吸道病毒基因的表达。 结果SRSNS活动期PBMC中呼吸道病毒基因的表达能被其相应的ASONs所抑制。呼吸道合胞病毒基因表达受抑制率为93.9%(14/15)，流感病毒受抑制率为87.5%(7/8)，总抑制率为91.3%(21/23)。 结论呼吸道病毒确实存在于SRSNS活动期病人体内，呼吸道病毒感染作为主要触发因素，可能为SRSNS的重要发病机制。     

In vitro fertilization and embryo transfer program in Clamart,France

Our in vitro fertilization and embryo transfer program really began in September 1980. Yet attempts to collect oocytes had been performed since 1978, and the first in vitro fertilizations were obtained in May 1979. The first pregnancy was obtained in April 1981, but it ended on the 12th week by a spontaneous abortion of a 45,X fetus. We have distinguished two periods in our program: The initial phase was from September 1980 until November 1982: ovulation monitoring of 365 cycles, spontaneous or stimulated, 276 laparoscopies, and 121 embryos transfers were performed, and 12 early pregnancies obtained (4.3% per laparoscopy and 9.9% per embryo transfer). Seven normal healthy infants were born (five boys and two girls); four cases were limited to biochemical pregnancies and one spontaneous abortion (yet described) was observed. The second and actual phase, December 1982–June 1983, is described more precisely: ovulation monitoring of 329 cycles, after stimulation protocols with clomiphene citrate and human menopausal gonadotropin, 230 laparoscopies, and 162 embryos transfers have been performed and have led to 34 pregnancies (14.8% per laparoscopy and 20.9% per embryo transfer). Eighteen of these 34 pregnancies are actually in progress (more than 12 weeks), 9 were limited to an increase in plasma human chorionic gonadotropin, and 7 cases ended in spontaneous abortions between 6 and 12 weeks.