Objective <p>To evaluate whether the timing of luteal phase support (LPS) initiation affects pregnancy outcomes in natural cycle vitrified-warmed blastocyst transfer (NC-FET) cycles.</p> Methods <p>This retrospective cohort study included NC-FET cycles performed between January 2022 and December 2024 at a tertiary university fertility center. Only true natural cycles with blastocyst transfer were analyzed. Patients were divided into two groups according to the initiation of LPS: two days before embryo transfer (Group 1) or on the day of embryo transfer (Group 2). All patients received vaginal and subcutaneous progesterone for LPS. Baseline characteristics, embryo features, serum progesterone levels on transfer day, and reproductive outcomes were compared. Multivariate logistic regression and receiver operating characteristic (ROC) analyses were performed to identify factors associated with clinical pregnancy.</p> Results <p>A total of 246 NC-FET cycles were analyzed (Group 1: <i>n</i> = 172; Group 2: <i>n</i> = 74). Baseline characteristics, embryo quality, and transfer parameters were comparable between groups. Serum progesterone levels on the day of transfer were significantly higher in Group 1 (32.1 ± 13.0 ng/mL) compared with Group 2 (10.3 ± 3.8 ng/mL; <i>p</i> = 0.001). However, total pregnancy rate (66.2% vs. 47.1%, <i>p</i> = 0.006), clinical pregnancy rate (56.8% vs. 40.7%, <i>p</i> = 0.020), and live birth rate (52.7% vs. 37.2%, <i>p</i> = 0.024) were significantly higher in Group 2. Logistic regression analysis showed that initiation of LPS on the day of transfer was independently associated with increased clinical pregnancy (OR 2.37, 95% CI 1.17–4.81). Serum progesterone level did not predict pregnancy outcomes.</p> Conclusion <p>In NC-FET cycles, initiating luteal phase support on the day of embryo transfer is associated with improved pregnancy and live birth rates compared with earlier initiation, despite lower serum progesterone levels.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Is there an effect of the start day of luteal phase support on pregnancy outcomes in natural vitrified-warmed blastocyst transfer?

  • Batuhan Turgay,
  • Batuhan Özmen,
  • Cem Somer Atabekoğlu,
  • Yavuz Emre Şükür,
  • Murat Sönmezer,
  • Bülent Berker,
  • Ruşen Aytaç

摘要

Objective

To evaluate whether the timing of luteal phase support (LPS) initiation affects pregnancy outcomes in natural cycle vitrified-warmed blastocyst transfer (NC-FET) cycles.

Methods

This retrospective cohort study included NC-FET cycles performed between January 2022 and December 2024 at a tertiary university fertility center. Only true natural cycles with blastocyst transfer were analyzed. Patients were divided into two groups according to the initiation of LPS: two days before embryo transfer (Group 1) or on the day of embryo transfer (Group 2). All patients received vaginal and subcutaneous progesterone for LPS. Baseline characteristics, embryo features, serum progesterone levels on transfer day, and reproductive outcomes were compared. Multivariate logistic regression and receiver operating characteristic (ROC) analyses were performed to identify factors associated with clinical pregnancy.

Results

A total of 246 NC-FET cycles were analyzed (Group 1: n = 172; Group 2: n = 74). Baseline characteristics, embryo quality, and transfer parameters were comparable between groups. Serum progesterone levels on the day of transfer were significantly higher in Group 1 (32.1 ± 13.0 ng/mL) compared with Group 2 (10.3 ± 3.8 ng/mL; p = 0.001). However, total pregnancy rate (66.2% vs. 47.1%, p = 0.006), clinical pregnancy rate (56.8% vs. 40.7%, p = 0.020), and live birth rate (52.7% vs. 37.2%, p = 0.024) were significantly higher in Group 2. Logistic regression analysis showed that initiation of LPS on the day of transfer was independently associated with increased clinical pregnancy (OR 2.37, 95% CI 1.17–4.81). Serum progesterone level did not predict pregnancy outcomes.

Conclusion

In NC-FET cycles, initiating luteal phase support on the day of embryo transfer is associated with improved pregnancy and live birth rates compared with earlier initiation, despite lower serum progesterone levels.