Natural cycles achieve better pregnancy outcomes than artificial cycles in non-PCOS women undergoing vitrified single-blastocyst transfer: a retrospective cohort study of 6840 cycles

The effects of unexpected follicular growth and ovulation in artificial cycles: a retrospective cohort study of frozen, single-blastocyst transfer

OBJECTIVE

To study the effects of unexpected follicular development and ovulation in artificial cycles (ACs) on pregnancy outcomes.

DESIGN

A retrospective cohort study.

SETTING

A university-affiliated fertility center.

PATIENT(S)

A total of 1,427 patients who underwent a single, frozen-thawed blastocyst transfer with AC regimens from January 2014 to December 2020 at a university-affiliated fertility center were included.

INTERVENTION(S)

Unexpected follicular development and ovulation in ACs.

MAIN OUTCOME MEASURE(S)

Live birth rate (LBR), biochemical pregnancy rate, clinical pregnancy rate, and ongoing pregnancy rate.

RESULT(S)

A total of 161 patients with unexpected follicular development and ovulation in ACs (ovulation group) and 1,266 patients without growing follicles in ACs (control group) were enrolled. The patients in the ovulation group were older and had higher levels of serum follicle-stimulating hormone and lower levels of serum antimüllerian hormone. After propensity score matching, the baseline characteristics between the 2 groups were comparable and no significant difference was observed in the LBR (ovulation group, 39.0% vs. control group, 39.0%), biochemical pregnancy rate (ovulation group, 60.3% vs. control group, 58.2%), clinical pregnancy rate (ovulation group, 53.4% vs. control group, 50.7%), or ongoing pregnancy rate (ovulation group, 42.5% vs. control group, 40.4%). Moreover, the patients in the ovulation group showed a lower risk of hypertensive disorders of pregnancy (HDP) (1.6% vs. 15.3%). A subgroup analysis of women who delivered singleton live-born babies also demonstrated that unexpected follicular development and ovulation in ACs was associated with a decreased risk of HDP (adjusted odds ratio, 0.070; 95% confidence interval, 0.007-0.712) and an increased risk of large-for-gestational-age infants (adjusted odds ratio, 4.046; 95% confidence interval, 1.319-12.414).

CONCLUSION(S)

Women with unexpected follicular development and ovulation during single frozen-thawed blastocyst transfer with AC regimens had a similar LBR and a reduced risk of HDP compared with those with routine AC regimens, and singleton neonates had an increased risk of being large for gestational age.

Gonadotropin-Releasing Hormone agonist (GnRH-a) Pretreatment before Hormone Replacement Therapy Does Not Improve Reproductive Outcomes of Frozen-Thawed Embryo Transfer Cycle in Older Patients with Intrauterine Fibroid: A Retrospective Cohort Study

BACKGROUND

Surgery in elder patients with intermural fibroids delays pregnancy, and GnRH-a can shrink uterine fibroids to a certain extent; therefore, for geriatric patients with fibroids, determining whether GnRH-a pretreatment before frozen-thawed embryo transfer (FET) can improve its success rate remains to be studied. We conducted this study to research whether GnRH-a pretreatment before hormone replacement treatment (HRT) could optimize the reproductive outcomes compared with others preparations in geriatric patients with intramural fibroids.

METHODS

According to the endometrial preparation, patients were divided into a GnRH-a-HRT group, a HRT group and a natural cycle (NC) group. The live birth rate (LBR) was the first outcome, and the clinical pregnancy outcome (CPR), the miscarriage rate, the first trimester abortion rate and the ectopic pregnancy rate were the secondary outcomes.

RESULTS

A total of 769 patients (aged 35 years or older) were included in this study. No significant difference was observed in the live birth rate (25.3% vs. 17.4% vs. 23.5%, p = 0.200) and the clinical pregnancy rate (46.3% vs. 46.1% vs. 55.4%, p = 0.052) among the three endometrial preparation regimens.

CONCLUSION

In this study, for the geriatric patient with the intramural myoma, the pretreatment with GnRH-a did not show any advantage over the NC and HRT preparation groups before the FET, and the LBR was not significantly increased.

Comparison of two endometrial preparation methods for frozen-thawed embryo transfer in anovulatory PCOS patients: impact on miscarriage rate

OBJECTIVE

- Some studies have suggested that patients with polycystic ovary syndrome (PCOS) are at high risk of miscarriage. However, this still remains controversial. Several potential factors might explain this association: obesity, hyperinsulinemia and hyperandrogenism. Artificial and stimulated cycles appear to be comparable for endometrial preparation in frozen-thawed embryo transfer (FET) in PCOS patients. Only a few studies have assessed miscarriage rates specifically in PCOS. We have evaluated the impact of endometrial preparation on FET outcomes in anovulatory PCOS patients.

METHODS

- A retrospective cohort study was conducted at the Lille University Hospital, including 255 FET cycles in 134 PCOS patients between January 2011 and December 2017. PCOS was defined by the presence of at least two of the three Rotterdam's criteria. Patients were under 35 years old. Two endometrial preparation protocol were studied: stimulated cycle (gonadotropins on the second day of the cycle and luteal phase support including natural progesterone 600 mg/day) and artificial cycle (6 mg oral estradiol valerate and 800 mg micronized vaginal progesterone daily).

RESULTS

- 137 FET were performed under stimulated cycle and 118 FET under artificial cycle. Early pregnancy rates (30% versus 37.3%, p = NS), miscarriage rates (22% versus 25%, p = NS) and live birth rates (23.4% versus 26.3%, p = NS) were similar.

CONCLUSIONS

- In anovulatory PCOS women, the type of endometrial preparation does not influence FET outcomes, specifically regarding the miscarriage rate.

"Double Frozen Transfer" Could Influence the Perinatal and Children's Growth: A Nested Case-Control Study of 6705 Live Birth Cycles

OBJECTIVE

This study aims to evaluate neonatal and children growth outcomes of cryotransfer of embryos developed from frozen gametes [double frozen transfer (DFT)].

METHODS

This nested case-control study included 6,705 women who had a singleton live birth after embryo transfer at the Center for Reproductive Medicine, Shandong University, from 2008 to 2020. Of these, 745 women underwent frozen embryo transfer (FET) using embryos developed from frozen gametes (DFT). Propensity score methodology was used to balance the two groups by maternal age and body mass index (BMI) before evaluating outcomes. After age and BMI were matched using the propensity score methodology in a ratio of 1:4, the control groups enrolled 2,980 women who underwent fresh embryo transfer (ET) and 2,980 women underwent FET from fresh gametes. The children born were followed to at least 5 years of age, and some were followed up to 10 years. Neonatal outcomes and childhood growth measurements were compared among the three groups.

RESULTS

The average birth weight of the DFT group (3,462 g) was significantly higher than the FET group (3,458 g) and ET group (3,412 g). The rate of large for gestational age (LGA) babies in the DFT and FET group was higher than that for the ET group (30.9% vs. 24.8%; 29.4% vs. 24.8%, respectively). After adjusting for different confounder combinations in the three models, the birth weight and risk of LGA in the DFT and FET groups were still higher than in the ET group, and the values group of P for trend in the models were significant. In multiple linear regression analysis of the children's development, the height Z-score of children born from the DFT and FET group was higher than that for children from the ET group (β = 0.21, 95% CI 0.07-0.35; b = 0.17, 95% CI 0.05-0.28, respectively). However, childhood growth measurements including body weight Z-score and BMI Z-score were not significantly different among the three groups. In addition, the proportion of male children born from DET was higher than that from ET.

CONCLUSIONS

There is an increased risk of LGA babies associated with pregnancies conceived from DFT. Children are inclined to be taller in the future in this group than after FET. The related etiology and pathophysiology mechanisms still need to be revealed. In the future, well-designed, observational studies with in-depth collection of patients' characteristics may shed more light on this issue.