The most common cause of death during or after childbirth is a hemorrhage. Nearly 125,000 women die from hemorrhage each year during childbirth, leading researchers to look into possible causes or markers that could shed light on why hemorrhage occurs. According to researchers at the University of Illinois at Chicago, the human placenta may be the key to understanding why these deaths occur.

Hemorrhage during childbirth is not a condition doctors can predict, but that could all change thanks to researchers. Instead of focusing on how to treat hemorrhage to reduce risks, researchers in this study chose to search for a root cause so doctors can be better prepared and possibly prevent hemorrhage.

When the placenta of humans was compared to that of other species, researchers found that human placentas attach deeper into the uterus. This leads to more blood loss during childbirth when the placenta detaches from the uterine wall. Trophoblasts, cells that provide nutrients to the placenta, may be the key to predicting the risk of hemorrhage. Abnormalities of the trophoblasts could be the topic of study in the future.

Another possible cause of hemorrhage is ineffective uterine contractions after childbirth. Bleeding is typically slowed by uterine contractions after birth. If uterine contractions are weak, bleeding can continue and lead to hemorrhage. While most postpartum deaths from hemorrhage occur within four hours of giving birth, some women experience dangerous hemorrhage weeks after giving birth.

The key finding in this study is the inherent differences between animal and human placental development. If researchers can figure out why animal placentas attach differently than human placentas, the research could lead to a treatment or cure for hemorrhage during childbirth.

Currently, the only definitive risk factors for hemorrhage during childbirth are a history of hemorrhage and delayed placental delivery. Delayed placental delivery may be associated with weak uterine contractions after birth.

Source: Julienne Rutherford and Elizabeth Abrams. University of Illinois at Chicago. 4 November 2011.