Estradiol Level on Day 2 and Day of Trigger: A Potential Predictor of the IVF-ET Success

OBJECTIVE: To evaluate role of serum estradiol levels in predicting likelihood of pregnancy in women undergoing GnRH-a protocol in IVF-ET cycles. DESIGN: A 3-year retrospective analysis of estradiol levels on down-regulated day 2, day 6, and day of hCG trigger and subsequent clinical pregnancy rates. SETTING: A university hospital tertiary referral centre. POPULATION OR SAMPLE: Women undergoing IVF treatment. METHODS: Hormonal assessment on the down-regulated day 2, day 6, and day of hCG trigger. MAIN OUTCOME MEASURES: Comparison of hormonal profile, antral follicular count on day 2, endometrial thickness on day of trigger, and number of oocytes retrieved between pregnant and the non-pregnant group. The prediction of IVF success was based on the quantitative levels of estradiol on a specific day in down-regulated cycle. RESULTS: The overall pregnancy rate was 32.25 % (50/160). Estradiol level on down-regulated day 2 was 31.9 ± 12.6 and on the day of trigger was 1,996.46 ± 1,252.36 in pregnant women, which was significantly higher as compared to estradiol levels in non-pregnant women (27.6 ± 12.3 and 1,525.1 ± 1,116.42, respectively). It was found to be a significant prognostic marker for successful IVF treatment. Estradiol levels on down-regulated day 6 were found to be non-significant between the two groups. CONCLUSIONS: Estradiol level on down-regulated day 2 of menstrual cycle and on the day of trigger was found to have a significant impact on the success of IVF-ET.