Seasonal Influence on Assisted Reproductive Technology Outcomes: A Retrospective Analysis of 1409 Cycles

BACKGROUND: It is well known that seasonal variations influence natural conception and birth rates variably in different populations. It has been hypothesised that similar seasonal influences may affect treatment outcomes following assisted reproductive technology (ART). However, most studies report conflicting results. AIM: The aim of the study is to elucidate whether seasonality had any impact on the treatment success of the ART program. STUDY SETTING AND DESIGN: We conducted a retrospective cohort study at a university-level tertiary care hospital in South India. MATERIALS AND METHODS: All couples who underwent ART between January 2012 and December 2016 were included in the study. We divided the study population into three groups based on the seasonal differences experienced in our region. The primary outcome was live birth rate (LBR). STATISTICAL ANALYSIS: Univariate and multiple logistic regression models were used to compare outcomes and results reported as odds ratio (OR) and 95% confidence interval (CI). RESULTS: Univariate analysis revealed no significant difference in LBR in monsoon season (174/651, 26.7% vs. 83/319, 26.0%; OR 1.04, 95% CI 0.77,1.41; P = 0.81) as compared to summer. However, LBR was significantly higher in winter season (114/341, 33.4% vs. 83/319, 26.0%; OR 1.43; 95% CI: 1.02, 2.00; P = 0.04). Further, multivariate analysis following adjustment for various confounding factors revealed no significant statistical difference in LBR in monsoon (adjusted odds ratio [aOR], 0.92; 95% CI: 0.66, 1.26; P = 0.59) or winter (aOR 1.32; 95% CI: 0.92, 1.88; P = 0.13) as compared to summer season. CONCLUSION: The current study found no significant effect of seasonal variation on LBR following ART.