An international study recently revealed that a C-section rate of 19 per 100 live births (19%) is correlated with the best outcomes for mothers and children in the modern world. Although I am by no means a supporter of the natural childbirth movement, this high number surprised me. Previous recommendations from the World Health Organization suggested an optimal rate between 10 and 15 %. Perhaps childbirth has become more difficult in the last hundred years. Women who would not have survived childbirth in the past are now in the position to pass on their genes to the next generation, even if they are unfavourable for giving birth.
The World Health Organization defines maternal mortality as “The death of a woman while pregnant or within 42 days of termination of pregnancy, irrespective of the duration and the site of the pregnancy, from any cause related to or aggravated by the pregnancy or its management, but not from accidental or incidental causes.“
What is the natural maternal mortality? Estimating the number of mothers who died from complications in pregnancy and birth in prehistory is tricky. When nothing effective is done to avert death, the ‘natural’ maternal mortality is estimated at 1500 per 100000 births (Van Lerberghe and De Brouwere 2001). Women in the poorest nations still face a lifetime risk of one in 16 to die in pregnancy or childbirth. Immediate complications range from obstructed labour to haemorrhage and infection. What is intriguing is that the real underlying cause of maternal mortality today is the social status of women: maternal and infant mortality is the result of factors such as poverty, access to healthcare and female participation in decision-making.
In the past, birth systems with a high rate of interventions did not normally improve things: two-thirds of mothers who gave birth in hospitals in Paris around 1660 died of puerperal fever, and about a quarter of mothers from privileged English households in the 17th and 18th century died of childbirth complications (Shorter 1982). Both delivered under a-typical circumstances, perhaps not representative for prehistoric societies.
At present, the best guess is probably a rate between 1.5 and 25 %. The number of women between the ages of 20 and 40 compared to the number of men in the same age bracket on any given prehistoric cemetery may be an additional clue, although the sex balance in cemeteries is often uneven for unknown reasons. Here is a lot of work for us to collect and evaluate data.
If you think this rate of maternal mortality is bad, it could be worse: rather than homo sapiens, you could be crocuta crocuta, the spotted hyena. This animal has an unusually long gestation and the infant is large and mature, with teeth fully erupted. The mother has to give birth through an ‘extraordinary organ the size and shape of a penis’. This leads to a death rate of 18 % for first-time mothers, and 65-70% for firstborn young.
Molina, G., T. G. Weiser, S. R. Lipsitz, and et al. 2015. Relationship between cesarean delivery rate and maternal and neonatal mortality. JAMA 314(21): 2263-2270.
Shorter, E. 1982. A History of Women’s Bodies. New York: Basic Books.
Van Lerberghe, W., and V. De Brouwere. 2001. “Of blind alleys and things that have worked: history’s lessons on reducing maternal mortality,” in V. De Brouwere and W. Van Lerberghe (eds) Safe motherhood strategies: a review of the evidence, Studies in Health Services Organisation and Policy 17. Antwerp: ITG Press: 7-33.
Save the Children. 2013. Surviving the First Day. State of the World’s Mothers 2013. Retrieved May 2013, from http://www.savethechildrenweb.org/SOWM-2013/files/assets/common/downloads/State%20of%20the%20WorldOWM-2013.pdf