Comparison of perinatal outcomes following frozen embryo transfer cycles using autologous versus donor oocytes in women 40 to 43 years old: analysis of SART CORS data

Perinatal outcomes in 6640 singleton pregnancies after donor oocyte IVF across three continents over 7 years

PURPOSE

Are trends in singleton donor oocyte IVF perinatal outcomes consistent over time among four international ethnically diverse infertility centers?

METHODS

This retrospective cohort consisted of an infertility network of four international IVF centers across three continents. Singleton live births resulting from fresh and frozen donor oocyte embryo transfers from January 1, 2012 to December 31, 2018 were included. The main outcome measures were birth weight (BW), preterm birth (PTB), large for gestational age (LGA), small for gestational age (SGA) and gestational age (GA) at delivery.

RESULTS

The entire cohort (n = 6640) consisted of 4753 fresh and 1887 frozen donor oocyte embryo transfers. Maternal age, parity, body mass index, neonatal sex and GA at delivery were similar for fresh and frozen donor oocyte embryo transfers in the entire cohort and within each infertility center. All four centers had a trend of decreased BW and rates of PTB before 32 weeks annually, although significance was not reached. Three of the four centers had annual increased trends of PTB before 37 weeks and LGA newborns, although significance was not reached. BWs for the entire cohort for fresh and frozen donor embryo transfers were 3166 g ± 601 g and 3137 g ± 626 g, respectively.

CONCLUSION

Similar trends in perinatal outcomes were present across four international infertility centers over 7 years. The overall perinatal trends in donor oocyte IVF may be applicable to centers worldwide, but further studies in more geographic regions are needed.

The developmental competence of human metaphase I oocytes with delayed maturation in vitro

OBJECTIVE

To evaluate whether metaphase I (MI) oocytes completing maturation in vitro to metaphase II ("MI-MII oocytes") have similar developmental competence as the sibling metaphase II (MII) oocytes that reached maturity in vivo.

DESIGN

Retrospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

A total of 1,124 intracytoplasmic sperm injection (ICSI) cycles from 800 patients at a single academic center between April 2016 and December 2020 with at least 1 MII oocyte immediately after retrieval and at least 1 sibling "MI-MII oocyte" that was retrieved as MI and matured to MII in culture before ICSI were included in the study.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

A total of 7,865 MII and 2,369 sibling MI-MII oocytes retrieved from the same individuals were compared for the fertilization and blastocyst formation rates. For patients who underwent single euploid blastocyst transfers (n = 406), the clinical pregnancy, spontaneous pregnancy loss, and live birth rates were compared between the 2 groups.

RESULT(S)

The fertilization rate was significantly higher in MII oocytes than in delayed matured MI-MII oocytes (75.9% vs. 56.1%). Similarly, the blastocyst formation rate was higher in embryos derived from MII oocytes than in those from MI-MII oocytes (53.8% vs. 23.9%). The percentage of euploid embryos derived from MII oocytes was significantly higher than that of those from MI-MII oocytes (49.2% vs. 34.7%). Paired comparison of sibling oocytes within the same cycle showed higher developmental competence of the MII oocytes than that of MI-MII oocytes. However, the pregnancy, spontaneous pregnancy loss, and live birth rates after a single euploid blastocyst transfer showed no statistically significant difference between the 2 groups (MII vs. MI-MII group, 65.7% vs. 74.1%, 6.4% vs. 5.0%, and 61.5% vs. 70.0%, respectively).

CONCLUSION(S)

Compared with oocytes that matured in vivo and were retrieved as MII, the oocytes that were retrieved as MI and matured to MII in vitro before ICSI showed lower developmental competence, including lower fertilization, blastocyst formation, and euploidy rates. However, euploid blastocysts from either cohort resulted in similar live birth rates, indicating that the MI oocytes with delayed maturation can still be useful even though the overall developmental competence was lower than that of their in vivo matured counterparts.

Birth outcomes are superior after transfer of fresh versus frozen embryos for donor oocyte recipients

STUDY QUESTION

For donor oocyte recipients, are birth outcomes superior for fresh versus frozen embryos?

SUMMARY ANSWER

Among fresh donor oocyte recipients, fresh embryos are associated with better birth outcomes when compared with frozen embryos.

WHAT IS KNOWN ALREADY

Frozen embryo transfer (ET) with vitrification has been associated with improved pregnancy rates, but also increased rates of large for gestational age infants. Donor oocyte recipients represent an attractive biological model to attempt to isolate the impact of embryo cryopreservation on IVF outcomes, yet there is a paucity of studies in this population.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort of the US national registry, the Society for Assisted Reproductive Technology Clinic Outcome Reporting System, of IVF cycles of women using fresh donor oocytes resulting in ET between 2013 and 2015. Thawed oocytes were excluded.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Good obstetric outcome (GBO), defined as a singleton, term, live birth with appropriate for gestational age birth weight, was the primary outcome measure. Secondary outcomes included live birth, clinical pregnancy, spontaneous abortion, preterm birth, multiple births and gestational age-adjusted weight. Outcomes were modeled using the generalized estimating equation approach.

MAIN RESULTS AND THE ROLE OF CHANCE

Data are from 25 387 donor oocyte cycles, in which 14 289 were fresh and 11 098 were frozen ETs. A GBO was 27% more likely in fresh ETs (26.3%) compared to frozen (20.9%) (adjusted risk ratio 1.27; 95% confidence interval (CI) 1.21-1.35; P < 0.001). Overall, fresh transfer was more likely to result in a live birth (55.7% versus 39.5%; adjusted risk ratio 1.21; 95% CI 1.18-1.26; P < 0.001). Among singleton births, there was no difference in gestational age-adjusted birth weight between groups.

LIMITATION, REASONS FOR CAUTION

Our cohort findings contrast with data from autologous oocytes. Prospective studies with this population are warranted.

WIDER IMPLICATIONS OF THE FINDINGS

Among donor oocyte recipients, fresh ETs may be associated with better birth outcomes. Reassuringly, given its prevalent use, modern embryo cryopreservation does not appear to result in phenotypically larger infants.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Endometrium preparation and perinatal outcomes in women undergoing single-blastocyst transfer in frozen cycles

OBJECTIVE

To investigate the association of endometrium preparation with perinatal outcomes.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated fertility center.

PATIENT(S)

Twenty-one thousand six hundred and forty-eight women who underwent frozen single-blastocyst transfer from January 2013 to March 2019.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Cesarean delivery, preterm delivery (PTD), vaginal PTD, very preterm delivery (VPTD), postterm delivery, low birth weight (LBW), macrosomia, small for gestational age (SGA), large for gestational age (LGA), hypertensive disorders of pregnancy (HDP), gestational diabetes mellitus (GDM), premature rupture of membrane (PROM), placenta previa, and congenital abnormality.

RESULT(S)

Compared with natural cycles, hormone replacement cycles were associated with an increased risk of PTD, VPTD, cesarean delivery, macrosomia, PROM, and HDP. There was a trend toward an increased risk of vaginal PTD and LGA in hormone replacement cycles. Stimulated cycles were associated with an increased risk of postterm delivery and GDM. There was no statistically significant difference in the rate of SGA, placenta previa, or congenital abnormality among the three endometrium preparation methods.

CONCLUSION(S)

Hormone replacement cycles are associated with an increased risk of PTD, VPTD, cesarean delivery, LBW, macrosomia, PROM, and HDP. Stimulated cycles are associated with an increased risk of postterm delivery and GDM.

Risk of adverse perinatal outcomes after oocyte donation: a systematic review and meta-analysis

RESEARCH QUESTION

In women with singleton pregnancies conceived after assisted reproductive technologies, does the in vitro fertilization with oocyte donation (IVF-OD) affect the perinatal and maternal outcomes compared to autologous in vitro fertilization (IVF-AO)?

DESIGN

Systematic review and meta-analysis of studies comparing perinatal and maternal outcomes in singleton pregnancies resulting from IVF-OD versus IVF-AO. An electronic literature search in Pubmed, MEDLINE, and Cochrane database was performed. The main outcome measures were hypertensive disorders in pregnancy, preeclampsia, severe preeclampsia, pregnancy-induced hypertension, preterm birth, early preterm birth, low birth weight, and very low birth weight.

RESULTS

Twenty-three studies were included. IVF-OD is associated with a higher risk of hypertensive disorders in pregnancy (OR 2.63, 2.17-3.18), preeclampsia (OR 2.64; 2.29-3.04), severe preeclampsia (OR 3.22; 2.30-4.49), pregnancy-induced hypertension (OR 2.16; 1.79-2.62), preterm birth (OR 1.57; 1.33-1.86), early preterm birth (OR 1.80; 1.51-2.15), low birth weight (OR 1.25, 1.20-1.30), very low birth weight (OR 1.37, 1.22-1.54), gestational diabetes (OR 1.27; 1.03-1.56), and cesarean section (OR 2.28; 2.14-2.42). There was no significant difference in the risk of preterm birth or low birth weight when adjusted for preeclampsia.

CONCLUSIONS

IVF-OD patients should be considered an independent risk factor for some adverse perinatal outcomes, mainly hypertensive disorders in pregnancy, preeclampsia, and severe preeclampsia. Immunological and hormonal aspects may be involved in these results, and further research focusing in the etiopathogenesis of these pathologies are needed.

The placental transcriptome of the first-trimester placenta is affected by in vitro fertilization and embryo transfer

BACKGROUND

The placenta is a highly specialized temporary organ that is related to fetal development and pregnancy outcomes, and epidemiological data demonstrate an increased risk of placental abnormality after in vitro fertilization and embryo transfer (IVF-ET).

METHODS

This study examines alterations in the transcriptome profile of first-trimester placentas from IVF-ET pregnancies and analyzes the potential mechanisms that play a role in the adverse perinatal outcomes associated with IVF-ET procedures. Four human placental villi from first-trimester samples were obtained through fetal bud aspiration from patients subjected to IVF-ET due to oviductal factors. An additional four control human placental villi were derived from a group of subjects who spontaneously conceived a twin pregnancy. We analyzed their transcriptomes by microarray. Then, RT-qPCR and immunohistochemistry were utilized to analyze several dysregulated genes to validate the microarray results. Biological functions and pathways were analyzed with bioinformatics tools.

RESULTS

A total of 3405 differentially regulated genes were identified as significantly dysregulated (> 2-fold change; P < 0.05) in the IVF-ET placenta in the first trimester: 1910 upregulated and 1495 downregulated genes. Functional enrichment analysis of the differentially regulated genes demonstrated that the genes were involved in more than 50 biological processes and pathways that have been shown to play important roles in the first trimester in vivo. These pathways can be clustered into coagulation cascades, immune response, transmembrane signaling, metabolism, cell cycle, stress control, invasion and vascularization. Nearly the same number of up- and downregulated genes participate in the same biological processes related to placental development and maintenance. Procedures utilized in IVF-ET altered the expression of first-trimester placental genes that are critical to these biological processes and triggered a compensatory mechanism during early implantation in vivo.

CONCLUSION

These data provide a potential basis for further analysis of the higher frequency of adverse perinatal outcomes following IVF-ET, with the ultimate goal of developing safer IVF-ET protocols.