Abstract:
Background: Previous studies on change in maternal age composition in Tanzania do not indicate
its impact on adverse pregnancy outcomes. We sought to establish temporal changes in maternal
age composition and their impact on annual Caesarean section (CS) and low birth weight deliveries
(LBWT) at Muhimbili National Hospital in Tanzania.
Methods: We conducted data analysis of 91,699 singleton deliveries that took place in the hospital
between 1999 and 2005. The data were extracted from the obstetric data base. Annual
proportions of individual age groups were calculated and their trends over the years studied.
Multiple logistic analyses were conducted to ascertain trends in the risks of CS and LBWT. The
impact of age composition changes on CS and LBWT was estimated by calculating annual numbers
of these outcomes with and without the major changes in age composition, all others remaining
equal. In all statistics, a p value < 0.05 was considered significant.
Results: The proportion of teenage mothers (12–19 years) progressively decreased over time
while that of 30–34 years age group increased. From 1999, the risk of Caesarean delivery increased
steadily to a maximum in 2005 [adjusted OR = 1.7; 95%CI (1.6–1.8)] whereas that of LBWT
declined to a minimum in 2005 (adjusted OR = 0.76; 95% CI (0.71–0.82). The current major
changes in age trend were responsible for shifts in the number of CS of up to206 cases per year.
Likewise, the shift in LBWT was up to 158 cases per year, but the 30–34 years age group had no
impact on this.
Conclusion: The population of mothers giving birth at MNH is progressively becoming older with
substantial impact on the incidence of CS and LBWT. Further research is needed to estimate the
health cost implications of this change.
