The efficiency of human reproduction after in vitro fertilization and embryo transfer

Early pregnancy losses in in vitro fertilization and oocyte donation

OBJECTIVE

To evaluate prospectively the incidence of early pregnancy losses (before menstruation occurs) in IVF and ovum donation cycles.

DESIGN

Prospective case-control study.

SETTING

Tertiary care, university-associated center.

PATIENT(S)

One hundred forty-five patients undergoing IVF and 92 undergoing oocyte donation were recruited. The control group for IVF consisted of 15 ovum donors who had no ET and were instructed to avoid intercourse. The control group for oocyte donation included 10 women undergoing a mock cycle of steroid replacement.

INTERVENTION(S)

Starting on day 6 after ET, the women were instructed to collect the first urine sample of the day every 2 days. Each patient collected six different specimens of urine (days 6, 8, 10, 12, 14, and 16 after ET for cases or the same days without ET for controls.

MAIN OUTCOME MEASURE(S)

beta-HCG was measured with a standardized microparticle enzyme immunoassay, and IVF reproductive outcome was assessed.

RESULT(S)

For IVF, positive implantation was registered in 88 of 145 cycles of embryo replacement (60.7%). Only 30 (20.7%) resulted in viable pregnancies, whereas the remaining 58 miscarried. Forty-two of these miscarriages (72.4%) were early pregnancy losses and 13 (22.4%) were classified as clinical abortions. In ovum donation, positive implantation was recorded in 64 of 92 cycles of ET (69.6%). A total of 30 (32.6%) ended in viable pregnancies, whereas the remaining 34 (37.0%) were miscarriages. Early pregnancy loss accounted for 70.6% of pregnancy losses, whereas biochemical pregnancies and clinical abortions accounted for 11.8% and 17.6%, respectively.

CONCLUSION(S)

Our results demonstrate that patients undergoing assisted reproductive technology have an increased rate of early pregnancy loss compared with fertile patients. In addition, these data indicate that implantation is more frequently impaired in IVF than in oocyte donation cycles, resulting in a high incidence of early pregnancy loss. This suggests that implantation may be subjected to abnormal conditions in assisted reproduction.

Comparison of transdermal versus oral estradiol on endometrial receptivity

OBJECTIVE

To compare the effects of oral micronized E2 with transdermal E2 on endometrial receptivity in women undergoing oocyte donation.

DESIGN

Prospective, randomized, crossover trial. Serum E2 and P concentrations were measured on cycle days 14 and 22 (luteal day +8). Endometrial biopsies were obtained on day 22 and read in a blinded fashion for histology and beta-3-integrin expression.

SETTING

University-based donor oocyte program.

PATIENTS

Twenty-seven patients presenting for donor oocytes.

MAIN OUTCOME MEASURES

Endometrial histology and beta-3-integrin expression.

RESULTS

The endometrial glandular histology in women given oral micronized E2 was delayed by a mean of 1.6 days in comparison to that of women given transdermal E2. Seventy percent of women given oral E2 displayed a lag > or = 4 days whereas 29.6% given transdermal E2 displayed a similar lag. Serum E2 levels were 1,194 +/- 108.8 pg/mL (mean +/- SEM; conversion factor to SI unit, 3.671) in women on oral micronized E2 and 117.4 +/- 14.0 pg/mL in those on transdermal E2.

CONCLUSION

The supraphysiologic serum E2 levels associated with oral micronized E2 may have a deleterious impact on endometrial receptivity. The development of more physiologic hormone replacement protocols may enhance endometrial receptivity and lead to improved clinical pregnancy rates.

Endometriosis: a stage by stage analysis--the role of in vitro fertilization

OBJECTIVE

To investigate the impact of endometriosis stage on IVF.

PATIENTS

A retrospective study of 214 patients diagnosed with endometriosis who underwent 360 cycles of IVF at The New York Hospital-Cornell Medical Center. Meanwhile, 111 pure mechanical (tubal) infertility patients treated in 160 cycles at the same time were designated as the control group for comparison.

MAIN OUTCOME MEASURES

Patient's hormone and semen profiles, hormonal response and outcome to stimulation, as well as the outcome of pregnancy, abortion, and delivery rate were analyzed.

RESULTS

No differences in the pregnancy outcome between the endometriosis and control groups were noted when compared among the subgroups of pure endometriosis, endometriosis plus tubal factor, endometriosis plus others (primarily endometriosis plus male factor), and control. Comparing the outcomes in pure endometriosis cases by staging, we could not find any discrepancies in terms of pregnancy rates (PRs) according to the severity of the disease. The addition of GnRH analogur down-regulation to gonadotropin stimulation resulted in an increase in PR. A relatively high delivery rate (38.9% per cycle, 41.9% per retrieval, and 43.2% per transfer) was achieved when the pure endometriosis patients were treated with concomitant leuprolide acetate down-regulation and gonadotropin.

CONCLUSION

We have observed that pregnancy outcome in patients with endometriosis was not different than the outcome for patients with mechanical (tubal) infertility. There were no differences in PRs by stage of endometriosis.

The impact of embryonic development and endometrial maturity on the timing of implantation

OBJECTIVE

To gain insight into the peri-implantation period in the human and to answer the question whether timing of nidation is dependent on the stage of embryonic development, endometrial maturation, or a possible dialogue between the two.

DESIGN

Seventy-five women underwent embryo transfer (ET) throughout 93 cycles. Thirty-three ETs resulted in viable pregnancies and deliveries. These pregnancy cycles were used for embryonic signal detection. Embryos of identical age were transferred onto hormonally and histologically defined endometria of different maturational stages (days 15 to 19). Human chorionic gonadotropin (hCG) was measured by a hypersensitive chemiluminescence assay in maternal serum every 1 to 5 days to detect the first embryonic signal.

RESULTS

Individual linear regressions of hCG versus embryonic age and endometrial maturation were performed on 33 viable pregnancy cycles (r2 = 90.5% to 99.9%, P less than 0.02 to 0.002). First signal detection was restricted to an embryonic age of 7.1 +/- 0.28 (mean +/- SD) days (range 6.6 to 7.4) irrespective of endometrial maturation. The pattern of hCG detection was triphasic, described by a sigmoidal curve with the maximal slope corresponding to an hCG doubling time of 15.9 hours. Embryo transfers on cycle day 19 had a steeper slope of hCG detection than days 15 and 16 (P less than 0.05).

CONCLUSIONS

First embryonic signal detection (presumed window of implantation) extends between cycle days 20 and 24. Implantation is dependent on embryonic age and is independent of endometrial maturation within this window. The timing and sigmoidal pattern of hCG detection coincides with structural changes of the implantation bed. The steeper slope of late ETs may represent a compensatory mechanism for late maternal recognition of pregnancy for corpus luteum rescue.

Improved pregnancy outcome with gonadotropin releasing hormone agonist (GnRH-a) stimulation is due to the improvement in oocyte quantity rather than quality

The impact of gonadotropin releasing hormone agonist (GnRH-a) on the quality and quantity of oocytes harvested in in vitro fertilization-embryo transfer (IVF-ET) patients was studied by comparing the results for patients stimulated with gonadotropin alone and with gonadotropin plus GnRH-a. Adding GnRH-a significantly improved the viable pregnancies per transfer and reduced the spontaneous abortions, which seemed to improve oocyte quality. However, when oocyte quality was evaluated by the fertilization rate and the implantation and delivery rates per embryos transferred, there were no significant difference in the results, indicating that GnRH-a did not improve the oocyte quality. On the other hand, GnRH-a significantly increased the average number of oocytes harvested, fertilized, and transferred, and this increased number of oocytes transferred has been demonstrated to increase pregnancy and multiple-pregnancy rates. Multiple pregnancy with more embryos implanted would significantly reduce the abortion rate. Abortion rates decreased inversely to the number of embryos implanted. Our data strongly suggest that the efficacy of GnRH-a on IVF-ET patients was due more to the quantity increase than the quality of embryos transferred.

The obstetric and neonatal outcome of pregnancy in women with a previous history of infertility: a prospective study

OBJECTIVE

To compare the frequency of common antenatal problems, the amount of antenatal surveillance and the obstetric and neonatal outcome in women with and without a history of infertility.

DESIGN

A prospective cohort study with age and parity matched controls.

SETTING

A single consultant unit at the Jessop Hospital for Women, Sheffield, over a 22-month period.

SUBJECTS

114 women with a history of infertility who reached 16 weeks gestation with a singleton live fetus and 114 control women matched for age and parity.

MAIN OUTCOME MEASURES

Frequency of antepartum complications, amount of antepartum surveillance, obstetric and neonatal outcome.

RESULTS

Common antenatal complications were not increased. In the infertility compared with the control group, the relative risk of requiring an emergency caesarean section was 2.43 (95% CI 1.05-5.63). There was no difference in birthweight.

CONCLUSION

Many of the previously observed differences in outcome of pregnancy in women after infertility compared with those without are associated with age and parity but these characteristics do not explain the increased frequency of emergency caesarean section.

Very early pregnancy wastage in in vitro fertilization and embryo transfer (IVF-ET)

The occurrence and incidence of early pregnancy wastage in an in vitro fertilization and embryo transfer (IVF-ET) program have been studied in 750 patients. In 297 (39.6%) a pregnancy was diagnosed; of these, 14.8% were biochemical and 24.8% clinical pregnancies. In the latter group 23.6% aborted, while 75.8% had clinical ongoing pregnancies. The mean embryo quality score of the biochemical pregnancy group was similar to that of the clinical ongoing pregnancy group but statistically different from that of the clinical abortion group (P less than 0.005). Furthermore, the clinical ongoing pregnancy rate in women with previous biochemical pregnancy was 24.7%, a significantly higher percentage compared to clinical ongoing pregnancies achieved in IVF-ET cycles (P less than 0.05). It is possible that biochemical pregnancy does not represent an index for infertility but rather an intact stage of reproduction leading toward implantation. The high clinical pregnancy rate in subsequent cycles may probably serve as an encouraging sign or a marker for future clinical pregnancy.

Late luteal estradiol patterns are a better prognosticator of pregnancy outcome than serial beta-human chorionic gonadotropin concentrations

OBJECTIVE

Since the corpus luteum (CL) is known to play an important role in early pregnancy, its activity could possibly be a marker for pregnancy outcome.

DESIGN

The late estradiol (E2) concentration in 48 viable pregnancies and 39 pregnancies which resulted in spontaneous abortions after in vitro fertilization and embryo transfer were used to evaluate such predictability.

SETTING

All patients studied were of the Center for Reproductive Medicine at Cornell University Medical College.

PATIENTS, PARTICIPANTS

Eighty-seven patients.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Serum E2 and human chorionic gonadotropin (hCG) concentrations on day +11, +13, +15 (day +1 = day of ovum pick-up) were measured and studied.

RESULTS

The late luteal CL activity after rescue had a positive correlation with the number and quality of the implanted embryos. Reduced CL activity was indicative of abortion. The late luteal E2 pattern when compared with hCG doubling time had a better abortion predictability (37.8% versus 63.9%, respectively).

CONCLUSION

Corpus luteum activity demonstrated to be a better prognosticator of abortion than serial beta-hCG titers.

The prognostic value and significance of preclinical abortions in in vitro fertilization-embryo transfer programs

Preclinical abortions occur in natural conceptions as well as in in vitro fertilization-embryo transfer (IVF-ET) cycles. Nevertheless, although known, this entity is ill defined.

OBJECTIVE

The purpose of this study was to propose a classification of these pregnancies on the basis of pathophysiological evidence and to evaluate their future clinical impact.

DESIGN

Of 970 IVF-ET cycles, 114 cycles (11.7%) terminated in preclinical abortions. Abortions were divided according to peak beta human chorionic gonadotropin (beta-hCG) values into chemical abortions (52%) occurring 2 weeks after ET with beta-hCG values not higher than 21 mIU/mL and peri-implantation abortions (47%) terminating spontaneously 4 weeks after ET; the latter had higher beta-hCG values for a longer period of time but without any sonographic evidence of gestational sac. No woman in the two groups needed curettage.

RESULTS

After a chemical abortion, the pregnancy outcome had better ongoing pregnancy rates (24.7%) in comparison with the 17% achieved in the total IVF-ET cycles.

CONCLUSIONS

It is concluded that these two groups most probably have different pathophysiological backgrounds and concomitantly different future clinical impacts.

Early pregnancy wastage in IVF (in vitro fertilization) patients

Human in vitro fertilization is characterized by a low efficiency of implantation. Possible mechanisms for pregnancy loss are discussed. Embryo viability or quality, abnormal implantation, and delayed or absent corpus luteum rescue may all play a role in pregnancy wastage. Defining the possible mechanism for these losses may allow hormonal treatment to correct specific abnormalities.

Are in-vitro fertilisation and embryo transfer of benefit to all?

The efficacy, safety, costs, and benefits of in-vitro fertilisation and embryo transfer (IVF/ET) have been reviewed. IVF/ET benefits only a small proportion of infertile women, it is expensive, and has serious health risks. Therefore policies for the management of infertility in which most financial and manpower resources are applied to prevention of infertility must be developed. Health authorities should also require accreditation of IVF/ET programmes, certification of providers, and ongoing monitoring of clinics. Full and accurate information on IVF/ET must also be disseminated, so that individuals seeking treatment for infertility can make the best informed choice about their care and health authorities can decide the place of IVF/ET in their infertility services.

Mechanisms and factors of early pregnancy wastage in in vitro fertilization-embryo transfer patients

Although the pregnancy rate per transfer of the Norfolk In Vitro Fertilization-Embryo Transfer (IVF-ET) program has been reported as between 25% and 35%, the viable pregnancy rate per transfer is only 15% to 20%. An understanding of the mechanism(s) and etiologic factors of miscarriage among IVF patients might suggest changes that could prevent some early pregnancy wastage. Forty-seven consecutive single pregnancies and 26 miscarriages (October 1985 to November 1986) were included in this study. Factors such as implantation time, date of corpus luteum rescue (CLR), embryo quality, and corpus luteum activity after rescue were studied and compared between term pregnancy and miscarriage groups. Results are discussed in detail in this paper.