The Statistical Distribution and Determinants of Mother’s Age at First Birth

Abstract

The age at which child bearing begins, influences the number of children a woman bears throughout her reproductive period in the absence of any active fertility control. This study employed both parametric and non-parametric survival analysis techniques, with a cohort of women within the reproductive age (15-49 years), to determine the statistical distribution of the age at first birth of a woman from her time of birth and identify the significant prognostic factors determining the timing of first birth of Ghanaian women. Using data from the Ghana Demographic and Health Survey (GDHS), the study fitted several parametric Accelerated Failure Time models, from which the best parametric distribution for age at first birth was selected. The results revealed that, the average age at first birth was about 20 years, with more than 87.4% of the women having giving birth before they attained 25 years of age. The age at first birth among the Ghanaian women was best modeled by the log-logistic model. By this model, the age at which a woman had her first birth was determined, at the 10% significance level, by her Age at first marriage, her Educational level, her Wealth Status and whether or not the women practiced family planning before their first birth.