The effect of LH rise during artificial frozen–thawed embryo transfer (FET) cycles

Abstract

Purpose: To evaluate the association between a rise in serum luteinizing hormone (LH) levels during artificial frozen– thawed embryo transfer (FET) cycles and clinical pregnancy rate. Methods: A retrospective cohort study of women undergoing artificial FET cycles. We compared cycles in which LH double itself from the early follicular phase and further (group A) to cycles without a rise in LH (group B). Endometrium preparation was achieved by administration of 2 mg three times per day estradiol valerate tablets. Embryo transfer (ET) was conducted after achieving endometrial thickness > 7 mm and vaginal progesterone was added according to the embryo’s age. A beta-hCG was measured 13–14 days after ET. Clinical pregnancy was diagnosed on transvaginal ultrasound. Results: Data from 984-FET cycles were retrieved. LH, exogenous estradiol (E2), progesterone values, endometrial thickness, and pregnancy outcomes were available in all patients. From 984-FET cycles, 629 (63.9%) had a doubling, and 355 (36.07%) had no rise in LH. Patients mean age was 30 years, similar in both groups. A multivariable logistic regression analysis was calculated to assess the effect of LH rise and pregnancy outcomes, after adjusting for confounders including a rise in E2 level and endometrial thickness. In this model, there was no association between doubling LH values and pregnancy rates (adjusted odds ratio: 1.06, 95% CI: 0.75–1.5, P = 0.74). Conclusion: LH rise during artificial FET cycles does not alter pregnancy rates. Apparently, hormonal monitoring of LH levels may not yield useful information in the artificial FET cycle and may be omitted.

Keywords

• lh
• clinical pregnancy
• artificial
• frozen embryo