A large study in Denmark produced findings that show a significant, but slight, increase in the rate of stillbirths and ectopic pregnancies as a result of previous caesarean sections.
The study looked at 832,996 women and followed their progress after their first live births to their second live births, stillbirths, miscarriages, or ectopic pregnancies (pregnancy that occurs outside the uterus).
The researchers found that women that had previously given birth through caesarean sections have a 14% higher chance of a stillbirth in their next pregnancy. The C-sections did not significantly increase the risk of miscarriages in the second birth. Stillbirth is death of a 20-24-week-old fetus, while a miscarriage is the loss of a fetus before the 20th week of the pregnancy.
Researchers say the data displays some uncertainty due to caesarean sections that occur as a result of medical complications with the pregnancy, since these complications could already allude to future difficulties. The data is also incomplete and it does not contain certain risk factors related to the mothers, such as smoking history.
The study was conducted by researchers at University College Cork in Ireland and Aarhus University in Denmark, and was published in PLoS Medicine. The research is the result of other studies showing a worldwide increase in the number of caesarean sections in comparison to vaginal deliveries. The study offers some statistical examples. In 2012, 25% of all births in England were delivered through C-sections, while only 2% were in the 1950s. In China and a few places in South America 40-50% of births are delivered through C-sections.
Caesarean section deliveries involve a surgical cut made in the mother's abdomen and womb to deliver the baby. The purpose of the study was to understand the effects of the increased rate of such deliveries, and to extract information about any negative consequences that may arise because of it. With the current uncertainties and confounding findings, researchers will likely try to obtain more data to increase accuracy and produce more reliable conclusions.
Still, the authors of the study say that the findings "will assist women and health-care providers to reach more informed decisions regarding mode of delivery."
