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, 2019–21). 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.

Key Messages

What is already known on this topic

– Female sterilisation is the most widely used contraceptive method in India. Existing evidence on sterilisation failure is drawn almost entirely from small, single-centre hospital case series that lack a defined denominator.

What this study adds

– Using nationally representative NFHS-5 data, this study provides the first national estimate of female sterilisation failure (prevalence 0.34%; Pearl Index 2.87 per 100 woman-years). Sterilisation failure can occur at any point from one month to over two decades after the procedure and is disproportionately concentrated among women sterilised at mobile clinics/camps.

How this study might affect research, practice, or policy

– These findings support strengthening quality assurance at camp-based sterilisation services. Additionally, we need to revise post-sterilisation counselling and certification to clearly communicate that a missed period any time after sterilization can be an unintended pregnancy as a result of failure.