The incidence of ectopic/heterotopic pregnancies after blastocyst-stage frozen-thawed embryo transfers compared with that after cleavage-stage: a Society for Assisted Reproductive Technologies Clinical Outcomes Reporting System study

Association of endometrial preparation protocols and embryonic development stages with ectopic pregnancy in freeze-thaw cycles

PURPOSE

To investigate the correlation between endometrial preparation protocols, embryonic development stages, and ectopic pregnancy.

METHODS

A total of 29,700 clinical pregnancies, all of which resulted from freeze-thaw cycles performed between January 2018 and December 2023, were analyzed in this retrospective study.

RESULTS

The ectopic pregnancy rate was significantly higher in artificial cycles than natural cycles (1.5% vs. 0.8%; P < 0.001); the ectopic pregnancy rate was significantly higher in stage 5-6 than stage 3-4 blastocyst transfer (1.3% vs. 0.7%; P = 0.019). After incorporating all independent confounders into a multivariate general estimating equation model, artificial versus natural cycle (adjusted RR = 1.68, 95% CI = 1.32-2.13; P < 0.001) was shown to be an increased risk factor for ectopic pregnancy, especially in the single embryo transfer subgroup (aRR = 1.75, 95% CI = 1.23-2.48; P = 0.002); additionally, day 3 embryo transfer versus blastocyst transfer (aRR = 1.97, 95% CI = 1.15-3.38; P = 0.014) and stage 5-6 blastocyst versus stage 3-4 blastocyst transfer (aRR = 1.70, 95% CI = 1.05-2.74; P = 0.031) were shown to be increased risk factors for ectopic pregnancy.

CONCLUSIONS

This study found that endometrial preparation protocols and embryonic development stages are significantly associated with ectopic pregnancy.

Atosiban application in fresh ET cycle is effective for women undergoing repeated embryo implantation failures, especially for advanced-age obese patients

To assess the effect of atosiban in pregnancy outcomes of the fresh embryo transfer (ET), the retrospective cohort study was conducted. Six hundred and eighty-nine cases (using atosiban) and 1377 age and ET cycle-matched controls were collected from the January 2016 to May 2022 to perform the fresh IVF-ET cycle. The essential characteristics and pregnancy outcomes were analyzed. Conditional logistic regression analysis and subgroup analysis were performed. In the whole samples, atosiban had no effects in the pregnancy outcomes. Subgroup analyses suggested that atosiban could improve the clinical pregnancy in more than 3 ET cycles (OR 1.667, 95% CI 1.108-2.509, P = 0.014). Moreover, the improvement of clinical pregnancy was mainly present in the advanced-age women (age ≥ 35 years: OR 1.851, 95% CI 1.136-3.014, P = 0.013), obesity (BMI ≥ 24 kg/m2: OR 2.550, 95% CI 1.105-5.883, P = 0.028) and cleavage stage embryo (D3 embryo: OR 1.721, 95% CI 1.098-2.696, P = 0.018) among the repeated implantation failures (RIF). Atosiban could also improve the live birth for the obese women. Further, in the RIF, atosiban application was strongly recommended for the advanced-age infertility women, who also had the risk of obesity with the implantation of the cleavage stage embryo. In conclusion, atosiban could improve pregnancy outcomes for the advanced-age and obese women in RIF, especially while implanting the cleavage stage embryo in fresh ET cycle.