Even less is known about the extent of maternal illnesses in developing countries. A frequently cited estimate is 16 illnesses for each maternal death—a figure based on a 1980 study of one village in India (71). Applying this ratio to the entire developing world yields an estimate of eight million cases of nonfatal maternal complications every year (42, 191). Such complications are often chronic and debilitating.

Maternal mortality is usually expressed as the maternal mortality ratio—the number of maternal deaths per 100,000 live births. The maternal mortality ratio measures the risk of dying that a woman faces each time that she becomes pregnant (99, 318, 363). This ratio is often mistakenly called the maternal mortality rate. (A ratio compares the numbers of two differing events; a rate compares a part to the whole.)

Maternal mortality ratios range widely, from an estimated 12 maternal deaths per 100,000 live births in North America to more than 700 per 100,000 in some parts of sub-Saharan Africa (123, 312). For the developing world as a whole, maternal mortality is estimated at more than 400 deaths per 100,000 live births, while the ratio is below 30 per 100,000 in the developed world (312, 380) (see Table 1).

Due to poor health and poor health care, many women in developing countries face much greater risk in each pregnancy than most women in developed countries. They also face this risk more often because, on the average, they have more pregnancies. Thus the lifetime risk of maternal death—a statistic that reflects both the risk per pregnancy and the number of pregnancies—is far greater in most developing countries than in developed countries (see Table 1). Between one-fourth and one-third of all deaths among women in their reproductive years in developing countries are related to maternity compared with only one-half of 1% in the US (284).

In the developing world as a whole, any one pregnancy is, on average, about 16 times more likely to kill than in the developed world. And the higher fertility levels in developing countries double that relative risk over a woman's lifetime. Thus the average woman in developing countries is about 30 times more likely to die from pregnancy-related causes than the average woman in a developed country.