With the steady rise in births among women of advanced maternal age (AMA), it has become essential to examine how AMA influences pregnancy outcomes in northern Tanzania, a region where healthcare capacity and access remain limited. This investigation evaluated the relationship between AMA and maternal–fetal outcomes within this resource-restricted setting. Using data from the maternally linked Kilimanjaro Christian Medical Center (KCMC) Medical Registry, the study assessed 32,798 singleton deliveries documented between 2004 and 2013. Multiple logistic regression analyses generated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) to quantify the risk of adverse outcomes associated with AMA. Approximately 16% of the cohort fell into the AMA category, and this group showed significantly higher probabilities of cesarean delivery (aOR 1.32; 95%CI 1.24–1.41; P < 0.001), gestational diabetes (aOR 13.16; 95%CI 3.28–52.86; P < 0.001), pregestational diabetes (aOR 3.15; 95%CI 1.87–5.31; P < 0.000), and pre-eclampsia (aOR 1.63; 95%CI 1.41–1.89; P < 0.000). Compared with younger mothers, those in the AMA group more often reported consuming alcohol during pregnancy and had a greater prevalence of preexisting health conditions before conception. Maternal factors such as education, employment, urban living, and Christianity also showed significant associations. Overall, the findings indicate that AMA is strongly linked to heightened risks of cesarean section, diabetes (gestational and pregestational), and pre-eclampsia, alongside increased likelihoods of low birth weight, stillbirth, and NICU admission.
