Duration and determinants of birth interval in Yazd, Iran: a population study

Short birth intervals have been associated with adverse health outcomes, including infant, child and maternal mortality.

We aimed to investigate the duration and determinants of inter birth intervals among women of reproductive age in Yazd, Iran.

A cluster sampling technique was used to select 400 ever-married women aged 15-49 years in Yazd, Islamic Republic of Iran. Data were obtained by interview questionnaire and analyzed with life table, Kaplan-Meier survival and Cox regression analyses.

The mean duration of inter birth interval was 49.76 (standard error 1.82) months (95% CI: 46.19-53.34 months) with a median of 39. In 28.5% of women the birth interval was <2 years, in 28% it was 3-5 years and in 25.5% it was ≥6 years. Among explanatory variables of interest, age of marriage, and woman's education were significant predicators of the birth interval. Women who stated an ideal preference of two children constituted 59.9% of the sample and 16% had 3 children as well as 10.7% had an ideal preference for 4 or 5.

The study recommended an educational program to have optimal birth intervals and ideal number of children per family for the prevention of adverse prenatal outcomes.