Maternal mortality

A maternal death is defined by the World Health Organization (WHO) as ‘the death of a woman whilst pregnant or within 42 days of delivery or termination of pregnancy, from any cause related to, or aggravated by pregnancy or its management, but excluding deaths from incidental or accidental causes’ .

WHO estimates the global number of maternal deaths in 2015 to be 303,000 and the global average lifetime risk of a woman dying from pregnancy-related causes is 1 in 180. These numbers hide enormous differences not only between regions and countries but also within countries. The most striking difference exists between high-income and developing regions, where the latter account for 99% (an estimated 302,000 maternal deaths) of all maternal deaths. The average lifetime risk for a woman to die from pregnancy-related causes in developing regions is 1 in 150. The same risk in a high-income country is 1 in 4900 .

The number of maternal deaths occurring in a population is driven by four factors: the population size, the proportion of the population composed of women of childbearing age, the fertility rate and the risk of a woman dying whilst pregnant or within 42 days after delivery. The latter indicator is called the maternal mortality ratio (MMR) and is measured as the number of maternal deaths per 100,000 live births. The MMR, as a global average, was estimated as 216 per 100,000 live births in 2015 (80% uncertainty interval (UI) 206–249) , with sub-Saharan Africa at 546 (80% UI 511–652), Oceania at 187 (80% UI 95–381) and South Asia at 176 maternal deaths per 100,000 live births (80% UI 153–216).

In absolute numbers, this translates for sub-Saharan Africa, with its young population and high fertility rates, to an estimated 201,000 maternal deaths in 2015 (66% of the global total), followed by South Asia with an estimated 66,000 deaths the same year (22% of the global total) .

Differences among the countries within a region are also stark. Low MMR can only come about in countries with well-functioning health systems, and consequently the countries with the highest MMRs are the ones where the health system is functioning poorly. Many of these are countries with ongoing or recent conflicts or other types of crises (such as natural disasters or epidemics, including the recent Ebola virus outbreak in West Africa). Sierra Leone has the highest estimated MMR, 1360 per 100,000 live births (80 % UI 999–1980) in 2015, followed by the Central African Republic with a MMR of 882 (80% UI 508–1500) and Chad at 856 (80% UI 560–1350) ( Fig. 1 , Table 1 a and 1b ).

Country variation in maternal mortality rates in 2015.

Neonatal mortality

Neonatal deaths, that is, death within 28 days of birth among children born alive, is estimated as 2.7 million globally in 2015 .

Similarly to maternal deaths, the number of newborn deaths is a function both of the number of births in a region and the risk of newborns dying during their first 28 days of life, the neonatal mortality rate (NMR). Note that the maternal mortality is measured per 100,000 live births and the NMR is measured per 1000 live births. While the global NMR is estimated to be 19 per 1000 live births (90% UI 18–21) in 2015, the corresponding numbers in developed regions is 3 per 1000 live births ( Table 2 ).

The highest risk of death during the first 28 days of life exists in sub-Saharan Africa and South Asia, both with a NMR of 29 per 1000 live births and an estimated 1.0 and 1.1 million neonatal deaths, respectively, in 2015 . Neonates in Angola experience the highest risk globally (NMR 49), followed by Pakistan (NMR 46), Central African Republic (NMR 43) and Guinea-Bissau (NMR 40). The proportion of neonatal deaths among all under-five mortalities was 45% in 2015 and varied across regions from 29% in Africa to 54% in the Western Pacific ( Table 2 ).

Stillbirths

Stillborns are often not counted in national statistics and data are thus poor, especially from the developing regions with the highest burden of mortality.

Besides poor health information systems, inconsistent use of terminology contributes to low-quality data on stillbirths, and frequent misclassification of stillbirths and early neonatal deaths occurs. For instance, a neonate who dies just after birth may be misclassified as a stillbirth and the definition of when a dead foetus is to be counted as a stillbirth may vary across settings. For international comparisons, WHO recommends reporting of late foetal death as the death of a foetus that has completed 28 gestational weeks or more, weighs 1000 grams or more or has an at least 35 cm body length. The progress made in the last decades in neonatal intensive care of extremely preterm babies below 28 weeks of gestation challenges this classification.

The yearly number of stillborns was estimated to be 2.6 million (95% UI 2.1–3.8 million) in 2009. This corresponds to an estimated global stillbirth rate of 19 per 1000 births (95% UI 15–27 stillbirths per 1000 births) . The regions with the highest stillbirth rates in 2009 were South Asia (26.7 per 1000 births) and sub-Saharan Africa (28.3 per 1000 births). These regions also had a large number of births and consequently a large burden of stillbirths with 1.1 million (95% UI 0.9–1.7) and 0.9 million (95% UI 0.7–1.4) stillbirths in South Asia and sub-Saharan Africa, respectively . The five countries with the highest stillbirth rates in 2009 were Pakistan (47 per 1000 births), Nigeria (42 per 1000 births), Bangladesh (36 per 1000 births), Djibouti (34 per 1000 births) and Senegal (34 per 1000 births) ( Table 3 ).