Dados do Trabalho

Title

The use of LH levels on the day of hCG administration as a predictor of pregnancy in Frozen embryo transfer (FET) - a pilot study of quality improvement activity

Objective

To verify the mean values and standard deviation of serum luteinizing hormone (LH) on the day of hCG administration in FET cycles (natural cycle modified) for sample size calculation.

Methods

In this historical cohort, patients who underwent ovulation control for embryo transfer, between February and June 2023 at Clínica Proser - Porto Alegre, RS, Brazil - had their serum LH (U/l) measured on the day of human chorionic gonadotropin hCG injection according to local protocol; 7 weeks after embryo transfer, a transvaginal ultrasound was performed to verify the presence of an intrauterine pregnancy. The main outcome was the presence of an intrauterine gestational sac. Mean levels were compared between groups and the area under the curve was analyzed.

Results

The mean(±SD) levels of LH were 19.7±16.7 and 13.68±10.4 in women who got pregnant and not, respectively (p=0.2 Student t-test with Welch's correction). The area under the curve was 0.5981 (95%CI=0.398 to 0.797; p=0.3). The power of the study was 25%.

Conclusion

A minimum of 240 patients are required to have a 90% chance of detecting, as significant at the 5% level, a decrease in serum LH from 20 U/I in the pregnant group to 13 U/I in the non-pregnant group, based on this pilot study. The area under the curve found herein is similar to the one published in the literature.

Keywords

clinical pregnancy; frozen embryo transfer ; serum LH