Recent research has revealed a surprising fact: macaques, a species of Old World monkeys, have no maternal mortality linked to childbirth, despite their similarly narrow pelvis-to-head ratio compared to humans. This intriguing discovery challenges our understanding of the challenges faced by primates during labor and delivery. Explore the possible explanations behind this remarkable phenomenon and how it could inspire future studies on more physiological birth practices for humans.
The Macaque: Master.bating Birther
While human being death rates associated with childbirth can be high, particularly in unindustrialized countries without modern medical aid access, a study published yesterday reveals that Japanese macaques do not face any such risk. The study, which was carried out by scientists from the University of Vienna and the Medical University of Vienna, used long-term demographic data from a semi-free-living macaque population in Austria.
Over the 27 year study period, there were 281 infants born to 112 adult female macaques, and we did not find even one mother who died as a result of giving birth to her young. This extraordinary discovery flies in the face of the conventional wisdom that large brains and their associated large fetal head size are solely responsible for maternal mortality during birth, among primates at least.
For this population, we can demonstrate that it is possible for 27 years not a single female has died in conjunction with childbirth,” says Katharina Prof. Pink, midwife as well as evolutionary anthropologist at Medical University of Vienna, one of the two co-first authors.
Macaque Hips: The Key to Human Vulnerability in Childbirth?
But the study also hints that where macaques and pregnant women ultimately differ is in how much their pelvic girdles (and so, possibly, their pelvic floor muscles) open up when it comes time to push out a baby. Macaca also showed greater flexibility of the pelvis, especially in the pelvic girdle as well as in muscles of the pelvic floor than we know from humans, leading to less constrained birth dynamics due to differences in their male pubic symphysis compared with other taxa.
This heightened flexibility can help with the puzzles macaques faced if, like in humans, their pelvis-to-head ratio has limited their ability to squeeze through the birth canal. You may find macaques’ fondness for perching or squatting birthing positions –few as they are among non-human primate deliveries–might also account for the relatively easy time these animals have giving birth.
The findings may actually encourage more research into how unrestricted movement and upright delivery positions could benefit human mums, resulting in “less generic and less interventional care.” One thought here from midwife Pink is in this part of the article, how we have such different dynamics about giving birth with chimps and other primates, and she pointed out that more research effort needs to be put into this.
Relevance to Human Childbirth Interventions
The results of the macaque study suggest new possibilities for physiological birth practices in humans. We do not know the reasons for this absence of maternal mortality in macaques, but researchers hypothesize that more flexible pelvises and during labour may play a role in reducing the risks associated with human childbirth.
As midwife Pink explains, this understanding may set future studies in motion and result in the creation of care for human mothers that is slightly more tailored (and perhaps a little less intrusive! /) By examining the natural birth skills of our primate ancestors, we might be able to uncover strategies for helping women around the globe bring their children into this world with less risk and more personal control over the process — even in places where high-tech medicine is not an option.
The macaque study is a salient reminder that we still have much to learn from nature in order to comprehensively understand and optimize the human birth experience. When we understand more of our anatomy in this respect, it might teach us things about what sorts of health care for example pregnant women or people giving birth the kind of primate way may need a very different sort and that could a lot reshape future maternal healthcare and childbirth practices.
