Determinants of short birth intervals among married women: A cross-sectional study in Karachi, Pakistan

Sidrah Nausheen, Maria Bhura, Kristy Hackett, Imtiaz Hussain, Zainab Shaikh, Arjumand Rizvi, Uzair Ansari, David Canning, Iqbal Shah, Sajid Soofi

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


Introduction Birth spacing is a critical pathway to improving reproductive health. WHO recommends a minimum of 33-month interval between two consecutive births to reduce maternal, perinatal, infant morbidity and mortality. Our study evaluated factors associated with short birth intervals (SBIs) of less than 33 months between two consecutive births, in Karachi, Pakistan. Methods We used data from a cross-sectional study among married women of reproductive age (MWRA) who had at least one live birth in the 6 years preceding the survey (N=2394). Information regarding their sociodemographic characteristics, reproductive history, fertility preferences, family planning history and a 6-year reproductive calendar were collected. To identify factors associated with SBIs, we fitted simple and multiple Cox proportional hazards models and computed HRs with their 95% CIs. Results The median birth interval was 25 months (IQR: 14-39 months), with 22.9% (833) of births occurring within 33 months of the index birth. Women's increasing age (25-30 years (aHR 0.63 (0.53 to 0.75), 30+ years (aHR 0.29, 95% CI 0.22 to 0.39) compared with 20-24 years; secondary education (aHR 0.75, 95% CI 0.63 to 0.88), intermediate education (aHR 0.62, 95% CI 0.48 to 0.80), higher education (aHR 0.69, 95% CI 0.51 to 0.92) compared with no education, and a male child of the index birth (aHR 0.81, 95% CI 0.70 to 0.94) reduced the likelihood of SBIs. Women's younger age <20 years (aHR 1.24, 95% CI 1.05 to 1.24) compared with 20-24 years, and those who did not use contraception within 9 months of the index birth had a higher likelihood for SBIs for succeeding birth compared with those who used contraception (aHR 2.23, 95% CI 1.93 to 2.58). Conclusion Study shows that birth intervals in the study population are lower than the national average. To optimise birth intervals, programmes should target child spacing strategies and counsel MWRA on the benefits of optimal birth spacing, family planning services and contraceptive utilisation.

Original languageEnglish
Article number43786
JournalBMJ Open
Issue number4
Publication statusPublished - 26 Apr 2021


  • public health
  • reproductive medicine
  • sexual medicine


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