Determinants of imbalanced sex ratio at birth in Nepal: evidence from secondary analysis of a large hospital-based study and nationally-representative survey data

OBJECTIVES: To quantify sex ratios at births (SRBs) in hospital deliveries in Nepal, and understand the socio-demographic correlates of skewed SRB. Skewed SRBs in hospitals could be explained by sex selective abortion, and/or by decision to have a son delivered in a hospital—increased in -utero investments for male fetus. We use data on ultrasound use to quantify links between prenatal knowledge of sex, parity and skewed SRBs. DESIGN: Secondary analysis of: (1) de-identified data from a randomised controlled trial, and (2) 2011 Nepal Demographic and Health Survey (NDHS). SETTING: Nepal. PARTICIPANTS: (1) 75 428 women who gave birth in study hospitals, (2) NDHS: 12 674 women aged 15–49 years. OUTCOME MEASURES: SRB, and conditional SRB of a second child given first born male or female were calculated. RESULTS: Using data from 75 428 women who gave birth in six tertiary hospitals in Nepal between September 2015 and March 2017, we report skewed SRBs in these hospitals, with some hospitals registering deliveries of 121 male births per 100 female births. We find that a nationally representative survey (2011 NDHS) reveals no difference in the number of hospital delivery of male and female babies. Additionally, we find that: (1) estimated SRB of second-order births conditional on the first being a girl is significantly higher than the biological SRB in our study and (2) multiparous women are more likely to have prenatal knowledge of the sex of their fetus and to have male births than primiparous women with the differences increasing with increasing levels of education. CONCLUSIONS: Our analysis supports sex-selective abortion as the dominant cause of skewed SRBs in study hospitals. Comprehensive national policies that not only plan and enforce regulations against gender-biased abortions and, but also ameliorate the marginalised status of women in Nepal are urgently required to change this alarming manifestation of son preference. TRIAL REGISTRATION NUMBER: NCT02718222.