Objective To investigate the impact of prolonged ovarian stimulation on pregnancy outcomes in IVF cycles with fresh day 3 ET. Design Retrospective cohort study. Setting University-affiliated center. Patient(s) All patients initiating their first IVF cycle with fresh day 3 ET. Prolonged ovarian stimulation was defined as a duration of more than two standard deviations (95th percentile) for the study cohort (i.e., >13 days). Intervention(s) None. Main Outcome Measure(s) Live birth rate was considered the primary outcome and was compared between patients undergoing ovarian stimulation for ≤13 days and >13 days. Odds ratios (OR) with 95% confidence intervals (CI) for all pregnancy outcomes after day 3 ET were calculated. The OR for live birth was adjusted using logistic regression. Result(s) A total of 6,410 and 339 patients underwent ovarian stimulation for ≤13 days and >13 days, respectively. There were no differences in the demographics or mean number of day 3 embryos transferred between the two groups. Ovarian stimulation ≤13 days was associated with increased odds of clinical pregnancy (OR 2.15, 95% CI 1.19–3.89) and live birth (OR 2.35, 95% CI 1.25–4.43). The increased odds for live birth in the ≤13-day group remained unchanged after logistic regression. Patients with clinical pregnancies in the >13-day group were younger (34.6 ± 4.91 years) compared with those who did not conceive (38.2 ± 4.72 years). Conclusion(s) Our findings suggest that ovarian stimulation ≤13 days is associated with increased odds of clinical pregnancy and live birth. In patients undergoing ovarian stimulation >13 days, younger age is associated with live birth.
Pereira, N., Friedman, C., Hutchinson, A. P., Lekovich, J. P., Elias, R. T., & Rosenwaks, Z. (2017). Increased odds of live birth in fresh in vitro fertilization cycles with shorter ovarian stimulation. In Fertility and Sterility (Vol. 107, pp. 104-109.e2). Elsevier Inc. https://doi.org/10.1016/j.fertnstert.2016.09.044