Prevalence, Correlates, and Time-to-Event Analysis of Female Sterilisation Failure in India: A Nationally Representative Study Using NFHS-5 Data

Background: Female sterilisation is the most widely used contraceptive method in India. But nationally representative evidence on the frequency, outcome and correlates of sterilisation failure remains scarce. The objectives of this study were to estimate the prevalence of contraceptive failure, describe the outcomes of pregnancies resulting from failure, determine the time interval between sterilisation and failure, and compute the Pearl Index. Methods: This secondary data analysis used the Individual Recode dataset of the National Family Health Survey 5 (NFHS 5). Sterilisation failure was derived from reproductive and contraceptive history variables. Weighted prevalence, socio-demographic and procedural correlates, and a Pearl Index were estimated using survey-adjusted statistical methods. Results: Among 189,021 women who had adopted sterilisation, 623 (weighted prevalence 0.34%) experienced a failure. The most common outcome of sterilisation failure was abortion (96.0%). The Pearl Index was 2.87 failures per 100 woman-years (95% CI: 2.58, 3.20). Failure was significantly associated with years since sterilisation, decade and age at sterilisation, marital duration, parity, place and type of sterilisation (all p<0.05), but not with education, religion, caste, or wealth index. Failures occurred at any point from one month to over a decade after the procedure, with a disproportionately higher share among women sterilised at mobile clinics/camps. Conclusion: Female sterilisation failure in India, while uncommon, is not negligible and persists well beyond the immediate postoperative period. Procedural quality of care, particularly at camp-based settings, appears to be a key modifiable driver. The postoperative counselling needs to include a clear message that a missed period any time after (months to year) sterilisation can be a pregnancy resulting from failure of sterilization.