Maternal mortality fell by almost two-thirds in Matlab, Bangladesh, between 1976 and 2005, primarily because of improved emergency obstetric care and a decline in abortion-related mortality, according to a 30-year cohort study.¹ Although maternal mortality was stable during the first half of the study period, it declined markedly after 1989. Pregnant women were less likely to die if they lived in an area where health services were provided by an international research center or if they had five or more years of education; they were more likely to die if they were aged 30 or older or were pregnant for the first time.

In the study, researchers assessed trends in maternal mortality in two adjacent areas of rural Matlab: one served by the government, the other by the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B), which offered more extensive reproductive health services (in particular, better access to skilled birth attendants) than government facilities. Between 1976 and 2005, all births and deaths in Matlab were recorded and investigated through monthly household interviews, autopsy questionnaires and follow-up of deaths reported to a surveillance system. Maternal deaths (those that occurred during or within 90 days of pregnancy, excluding deaths due to injury) among women aged 15–49 were classified as related to obstetric causes (hemorrhage, hypertension, obstructed labor or infection), to abortion (spontaneous or induced) or to other causes. Multivariate analyses were conducted to identify possible determinants of maternal mortality, including service area (government or ICDDR,B), household assets, maternal education, maternal religion, maternal age, parity and time period (1976–1989 or 1990–2005); the researchers used 1989 as the cut-off for the last variable because that was the year in which skilled birth attendants became widely available in the ICDDR,B area. In some analyses, data from five-year periods were grouped together.

During the 30 years, 215,779 pregnancies and 769 maternal deaths were recorded. Between 1976–1980 and 2001–2005, the maternal mortality rate declined by 68% in the ICDDR,B area (from 412 to 131 deaths per 100,000 pregnancies) and by 54% in the government area (from 451 to 206 deaths per 100,000 pregnancies). In this period, there were marked reductions in the proportions of pregnant women who were completely un- educated (from 71% to 28%), who had had at least five prior pregnancies (from 26% to 10%) and who were aged 19 or younger (from 23% to 11%).

Multivariate analyses revealed that the risk of maternal mortality remained stable during the first half of the study period but fell by 4% per year beginning in 1990 (odds ratio, 0.96 for each additional year). For the study period as a whole, the odds of maternal mortality were 20% lower among women who resided in the ICDDR,B service area than among women who lived in areas with government facilities (0.8), and they were 40–60% lower among women with five to seven (0.6) or eight or more (0.4) years of education, compared with women with no formal education. In contrast, women aged 30–39 (1.8) or 40 or older (3.0) had a higher likelihood of death than their 20–29-year-old counterparts, and women who were pregnant for the first time had greater odds of maternal mortality than did women in their second or third pregnancy (2.4).

About three-fifths of maternal deaths were due to obstetric causes, primarily hemorrhage or hypertension. In multivariate analyses, the risk of obstetric death remained stable during both 1976–1989 and 1990–2005. Otherwise, the factors associated with obstetric death closely mirrored those of maternal mortality: The odds of obstetric death were reduced among women who resided in the ICDDR,B service area (odds ratio, 0.8) and those with five or more years of schooling (0.4–0.6), and elevated among women aged 30 or older (1.6–2.2) and women who were experiencing their first pregnancy (2.4).

About a fifth of maternal deaths were related to spontaneous or induced abortion, in most cases the latter. Abortion-related mortality was stable during 1976–1989 but fell by 8% annually in 1990–2005 (odds ratio, 0.92 per year). The odds of abortion-related death were markedly reduced among women with five or more years of education (0.1–0.4), and were elevated among women who were aged 30 or older (3.3–7.2) or were pregnant for the first time (3.8). Abortion-related mortality did not differ between areas.

The remaining one-fifth of maternal deaths were related to causes other than obstetric complications and abortion. In adjusted analyses, the rate of these deaths increased by 5% per year during 1976–1989 (odds ratio, 1.05) but decreased by 8% per year during 1990–2005 (0.92). The odds did not differ between the ICDDR,B and government areas.

Given that maternal mortality declined by two-thirds during the study period, the researchers believe that the fifth Millennium Development Goal—a 75% reduction in maternal mortality between 1990 and 2015—is within reach for Bangladesh. Because the use of skilled birth attendants remains low (even in the ICDDR,B service area, only half of births in 2005 involved a trained attendant), they believe that the decline in maternal mortality can be attributed primarily to policies that have increased access to family planning services, leading to fewer abortions; to the availability of safe, early abortions by manual vacuum aspiration ("menstrual regulation"); and to improvements in emergency obstetric care, particularly cesarean deliveries. How-ever, "additional policies that bring about expansion of female education, better financial access for the poor, and poverty reduction are essential to sustain the successes achieved to date," they add.—S. London

REFERENCE

1. Chowdhury ME et al., Determinants of reduction in maternal mortality in Matlab, Bangladesh: a 30-year cohort study, Lancet, 2007, 370(9595):1320–1328.