Effect of oocyte donor stimulation on recipient outcomes: data from a US national donor oocyte bank

Optimal antimüllerian hormone levels in oocyte donors: a national database analysis

OBJECTIVE

To study the relationship between high antimüllerian hormone (AMH) levels in oocyte donors and embryo development and pregnancy outcomes among donor oocyte recipients.

DESIGN

Retrospective cohort study.

SETTING

Donor Egg Bank Database.

PATIENTS

Patients undergoing in vitro fertilization using vitrified donor oocytes from 35 in vitro fertilization centers in the United States between 2013 and 2021. For each recipient, the first oocyte lot that was received with a planned insemination and embryo transfer (ET) was included.

INTERVENTION

Oocyte donor-recipient cycles.

MAIN OUTCOME MEASURES

Ongoing pregnancy rate (OPR) per ET.

RESULTS

A total of 3,871 donor oocyte-recipient thaw cycles were analyzed. On the basis of donor AMH serum concentration, cycles were stratified into the high AMH group (AMH ≥5 ng/mL; n = 1,821) and the referent group (AMH <5 ng/mL; n = 2,050). Generalized estimating equation models were used to account for donors that contributed more than one lot of oocytes. The number of usable embryos per lot (median [interquartile range]) was significantly increased in the high AMH group (2 [2-4]) compared with the referent group (2 [1-3]) (relative risk [RR] 1.06; confidence interval [CI] 1.01-1.12). Among recipients with a planned ET, there was no difference in OPR between the high AMH group (45.4%) and the referent group (43.5%) (RR 1.04; 95% CI 0.94-1.15). Among preimplantation genetic testing for aneuploidy cycles, the embryo euploidy rate per biopsy was similar at 66.7% (50%-100%) in both groups (RR 1.04; CI 0.92-1.17). The OPR per euploid ET among patients who used preimplantation genetic testing for aneuploidy was also comparable, at 52% in the high AMH group and 54.1% in the referent group (RR 0.95; CI 0.74-1.23).

CONCLUSION

This large national database study observed that there was no association between a high level of AMH (≥5 ng/mL) in oocyte donors and an OPR in the recipient after the first ET. On the basis of these findings, recipients and physicians can be reassured that oocyte donors with a high AMH level can be expected to produce outcomes that are at least as good as donors with an AMH level (<5 ng/mL).

Factors predicting clinical outcomes from 494 vitrified oocyte donation cycles at a UK-regulated egg bank

RESEARCH QUESTION

Do donor age, AMH, AFC, BMI and reproductive history predict response to ovarian stimulation? Do donor and recipient clinical markers and embryology parameters predict recipient pregnancy and live birth?

DESIGN

Retrospective cohort study of 494 altruistic oocyte donors aged 18-35 years; 340 were matched to 559 recipients. Predictors of donor total oocyte yield and total mature oocyte yield were identified. Total and mature oocyte number were compared according to stratified donor AMH and age. Donor, recipient and embryology parameters predictive of recipient primary outcomes (clinical pregnancy and live birth) were identified.

RESULTS

Donor age and AMH predicted total oocyte yield (P = 0.030 and P < 0.001)) and total mature oocyte yield (P = 0.011 and P < 0.001). Donors aged 30-35 years with AMH 15-29.9 pmol/l had lower total oocyte yield (P = 0.004) and mature oocyte yield (P < 0.001) than donors aged 18-24 years. Up to an AMH threshold of 39.9 pmol/l, increasing AMH levels predicted higher total oocyte yield (<15 pmol/l versus 15-29.9 pmol/l, P = 0.001; 15-29.9 pmol/l versus 30-39.9 pmol/l, P < 0.001; 30-39.9pmol/l versus ≥ 40 pmol/l, P = 1.0) and mature oocyte yield (<15 pmol/l versus 15-29.9 pmol/l, P = 0.005; 15-29.9 pmol/l versus 30-39.9 pmol/l, P = 0.006; 30-39.9 pmol/l versus ≥40 pmol/l, P = 1.0). In recipients, the rate of transferrable embryos per oocytes received, fertilized and number of embryo transfers needed to achieve the primary outcome were predictors of cumulative clinical pregnancy (P = 0.011, P = 0.017 and P < 0.001) and live birth (P = 0.008, P = 0.012 and P < 0.001) rates. Recipient BMI (P = 0.024) and previous miscarriages (P = 0.045) were predictors of cumulative live birth rate. Donor age 18-22 years was associated with a lower incidence of recipient clinical pregnancy (P = 0.004) and live birth (P = 0.001) after the first embryo transfer versus donor age 23-29 years.

CONCLUSIONS

Donor age and AMH are independent predictors of oocyte yield. Raised recipient BMI and history of miscarriages reduce cumulative live birth rates, which may be increased by selecting donors aged 23-29 years, instead of younger donors.

When using donor oocytes, does embryo stage matter? An analysis of blastocyst versus cleavage stage embryo transfers using a cryopreserved donor oocyte bank

PURPOSE

Oocyte donor in vitro fertilization (IVF) represents an ideal model to study the effects of embryo stage on reproductive success, as embryos come from young women with high-quality oocytes. Our study aimed to determine if embryo transfer stage affected outcomes in oocyte donor IVF, including the common scenario where only a limited number of quality embryos are available after culture.

METHODS

This retrospective cohort analyzed anonymous vitrified donor oocyte cycles at a single clinic between 2008 and 2015. Overall, 983 recipients underwent 1178 warming cycles resulting in fresh transfer of one-to-two embryos. Our primary outcome was live birth; secondary outcomes included multiple birth, birthweight, and gestational age. Log binomial regression with cluster-weighted generalized estimating equations were used to calculate adjusted risk ratios (aRR) accounting for recipient age, race, and transfer year.

RESULTS

Among 132 cleavage and 1046 blastocyst transfer cycles, cleavage transfers were associated with lower probability of live birth (aRR 0.72, 95% CI 0.59-0.88). Subgroup analysis focused on cycles with a limited number of quality embryos 3 days post-fertilization (≤2), as clinically these women were most likely to be considered for cleavage transfers. Among these cycles (120 cleavage, 371 blastocyst), cleavage transfers were still associated with lower live birth rates compared to blastocyst (aRR 0.66, 95% CI 0.51-0.87) CONCLUSIONS: Even in a donor oocyte model with high-quality oocytes, there was a benefit to extended culture and blastocyst transfer, including when only one-to-two quality embryos were available after early culture. This is possibly owed to improved uterine synchronicity or decreased contractility.

More than the oocyte source, egg donors as patients: a national picture of United States egg donors

PURPOSE

To characterize national oocyte donation practice patterns from the perspective of individual donors rather than of recipients.

METHODS

Retrospective cohort including all donor oocyte retrievals and transfers reported to SARTCORS in 2016 and 2017 in the USA. Primary outcomes include characteristics of oocyte donors and of donor oocyte cycles. Secondary outcomes include overall pregnancy rates, elective single embryo transfer (eSET) rates, and perinatal outcomes among donor oocyte recipient transfers.

RESULTS

During the study period, 49,193 donor oocyte retrievals were performed, of which the largest proportion were in the Western US. For all reported retrievals, there were 17,099 unique donors, each of whom underwent an average of 2.4 retrievals (range 1-22). Average donor age was 26.3 years (range 18-48). On average, 24.6 oocytes (SD 12.4) were retrieved each cycle, ranging from 0 to 102. Among 37,657 donor oocyte recipient transfers, 20,159 (53.5%) involved eSET, and 17,725 (47.1%) resulted in live birth. Miscarriage rates were 17.5%, and good perinatal outcome (GPO), defined as full-term normal birthweight delivery, was more likely among singleton (75.7%) than multiple (23.8%) pregnancies.

CONCLUSION

The average number of retrievals that donors underwent and oocyte yield mirrored national guidelines; however outliers, exist that may unnecessarily increase donor risk. Additionally, among resultant donor transfers, 46.5% transferred more than one embryo despite national recommendations for eSET. The significantly higher likelihood of GPO among singleton pregnancies points to the need to further increase donor recipient eSET rates.

Ovarian stimulation for oocyte donation: a systematic review and meta-analysis

BACKGROUND

Since its introduction in the 1980s, oocyte donation (OD) has been largely integrated into ART. Lately, both demand and the indications for OD have increased greatly. Oocyte donors are healthy and potentially fertile women undergoing voluntarily ovarian stimulation (OS). Selection of the optimal type of stimulation is of paramount importance in order to achieve the most favourable outcomes for the oocyte recipients, but most importantly for the safety of the oocyte donors.

OBJECTIVE AND RATIONALE

This is the first systematic review (SR) with the objective to summarize the current evidence on OS in oocyte donors. The scope of this SR was to evaluate the OD programme by assessing four different aspects: how to assess the ovarian response prior to stimulation; how to plan the OS (gonadotrophins; LH suppression; ovulation trigger; when to start OS); how to control for the risk of ovarian hyperstimulation syndrome (OHSS) and other complications; and the differences between the use of fresh versus vitrified donated oocytes.

SEARCH METHODS

A systematic literature search was conducted in May 2020, according to PRISMA guidelines in the databases PubMed and Embase, using a string that combined synonyms for oocytes, donation, banking, freezing, complications and reproductive outcomes. Studies reporting on the safety and/or efficacy of OS in oocyte donors were identified. The quality of the included studies was assessed using ROBINS-I and ROB2. Meta-analysis was performed where appropriate. Data were combined to calculate mean differences (MD) for continuous variables and odd ratios (OR) for binary data with their corresponding 95% CIs. Heterogeneity between the included studies was assessed using I2 and tau statistics.

OUTCOMES

In total, 57 manuscripts were selected for the review, out of 191 citations identified. Antral follicle count and anti-Müllerian hormone levels correlate with ovarian response to OS in OD but have limited value to discriminate donors who are likely to show either impaired or excessive response. Five randomized controlled trials compared different type of gonadotrophins as part of OS in oocyte donors; owing to high heterogeneity, meta-analysis was precluded. When comparing different types of LH control, namely GnRH antagonist versus agonist, the studies showed no differences in ovarian response. Use of progesterone primed ovarian stimulation protocols has been evaluated in seven studies: the evidence has shown little or no difference, compared to GnRH antagonist protocols, in mean number of retrieved oocytes (MD 0.23, [95% CI 0.58-1.05], n = 2147; 6 studies; I2 = 13%, P = 0.33) and in clinical pregnancy rates among recipients (OR 0.87 [95% CI 0.60-1.26], n = 2260, I2 = 72%, P < 0.01). There is insufficient evidence on long-term safety for babies born. GnRH agonist triggering is the gold standard and should be used in all oocyte donors, given the excellent oocyte retrieval rates, the practical elimination of OHSS and no differences in pregnancy rates in recipients (four studies, OR 0.86, 95%CI 0.58-1.26; I2 = 0%). OS in OD is a safe procedure with a low rate of hospitalization after oocyte retrieval. The use of a levonorgestrel intrauterine device or a progestin contraceptive pill during OS does not impact the number of oocytes retrieved or the clinical pregnancy rate in recipients. Ultrasound monitoring seems enough for an adequate follow up of the stimulation cycle in OD. Use of fresh versus vitrified donated oocytes yielded similar pregnancy outcomes.

WIDER IMPLICATIONS

This update will be helpful in the clinical management of OS in OD based on the most recent knowledge and recommendations, and possibly in the management of women under 35 years undergoing oocyte vitrification for social freezing, owing to the population similarities. More clinical research is needed on OS protocols that are specifically designed for OD, especially in term of the long-term safety for newborns, effective contraception during OS, and treatment satisfaction.

Mild stimulation should be mandatory for oocyte donation

The increasing commercialization of oocyte donation is a source of concern. This evolution is expressed in the fact that oocyte donors’ interests are not a priority. For decades now, people mention that oocyte donation holds serious health risks for donors, as if this is an unavoidable given. However, most of the harm is caused by high hormonal stimulation. The risk/benefit balance of high stimulation compared to the risk/benefit balance of mild stimulation does not justify causing greater harm to donors, especially given the fact that donors submit to the procedure without any medical benefit for themselves and to help others.