Factors associated with maternal mortality in rural Guinea-Bissau. A longitudinal population-based study.

OBJECTIVE: To assess demographic and obstetric risk factors for pregnancy-related death in a multiethnic rural population in a developing country. DESIGN: A prospective survey of women in the fertile age-range. SETTING: Rural Guinea-Bissau. POPULATION: More than 15,000 women living in 100 clusters were visited at six-monthly intervals over a period of more than six years. A total of 10,931 pregnancies were registered prospectively; 85 of these pregnancies resulted in maternal or late maternal death. MAIN OUTCOME MEASURE: Maternal mortality ratio. METHOD: In the rural areas of Guinea-Bissau, we conducted a prospective survey of women in the fertile age range. More than 15,000 women living in 100 clusters were visited at 6-monthly intervals over a period of more than six years. An analysis of demographic, environmental and obstetric risk factors for maternal death was performed based on 10,931 prospectively registered pregnancies; 85 of these pregnancies resulted in maternal or late maternal death. RESULTS: In the adjusted model maternal mortality ratio increased with increasing distance from the regional hospital (OR>25 km = 7.4 [95% CI: 1.6-132]). Multiple pregnancy was found to increase the risk of maternal death (OR = 3.4 [95% CI: 1.3-7.5]). The risk of subsequent maternal death was increased if the fetus was stillborn (OR = 5.3 [95% CI: 2.8-9.4]). Women living in the region of Gabu had higher mortality than those living in Biombo (OR = 2.5 [95% CI: 1.3-5.1]). No category of age or parity were associated with an increased risk of maternal mortality. Predictive values did not exceed 3% for any of the significant risk factors. CONCLUSIONS: For the purpose of reducing maternal mortality, the screening approach of antenatal care is of limited value. Age and parity should not be used routinely as selection criteria for transfer of otherwise healthy pregnant women to higher-level health institutions. Twin pregnancy seems to be the only operational risk factor identified in this study. Stillbirth is associated with an increased risk of maternal death. Regional differences must be studied further. The distance to emergency obstetric care (EOC) may determine the outcome of a complicated delivery.