Understanding C Section Risks

C sections linked to tiny increase in later stillbirth and ectopic pregnancy

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) The ability to bring babies into the world by cesarean section has undoubtedly saved millions of lives. Yet C sections can still carry additional risks.

Some of these additional risks may include an increased risk of stillbirth or ectopic pregnancy in later pregnancies, according to a recent study.

However, the increased risk is extremely tiny, and it's not clear that the C section itself is responsible for the increase.

Rather, the underlying conditions that required a C section may be the same factors related to stillbirth or ectopic pregnancy risk.

"Attend all prenatal visits."

This study, led by Sinead O'Neill, of the Department of Obstetrics and Gynecology at Cork University Maternity Hospital in Ireland, looked for possible links between a first-time C section and stillbirth, miscarriage or ectopic pregnancy.

An ectopic pregnancy occurs when the egg is fertilized by sperm in the fallopian tubes and remains there instead of implanting in the uterus. It is a life-threatening complication that requires removal of the embryo to prevent death of the mother.

The researchers tracked 832,996 Danish women who gave birth to their first child between January 1982 and December 2010.

The women were followed until they had a second birth, they died, they left the country or they had a stillbirth, miscarriage or ectopic pregnancy.

Comparison of women with first-time C sections and first-time vaginal births (not induced) revealed very tiny increased risks for stillbirths and ectopic pregnancies among those with C sections.

Only 0.03 percent more women with a first-time C section would experience a stillbirth that those with a first-time vaginal birth would not.

It would require 3,333 C sections for one later stillbirth to occur.

Similarly, only 0.1 percent more women with a first-time C section would experience an ectopic pregnancy that those with a first-time vaginal birth would not.

It would require 1,000 C sections before a single ectopic pregnancy would later occur among these women.

There was no increased risk of miscarriage among women who had a first-time C section.

The researchers made adjustments to account for the women's age, socioeconomic status, marital status, history of pregnancies, history of pregnancy complications and the child's birth date, birthweight and gestational age (pregnancy week when born).

However, the researchers did not have the information to account for mothers' weight, smoking or fertility treatments or the causes of stillbirth or C sections.

This missing data make it very difficult to know whether the increased risk was actually related to the C sections.

Andre Hall, MD, an OBGYN at Birth and Women's Care, PA in Fayetteville, NC, emphasized the importance of C sections in reducing risks during childbirth when the C sections are medically required.

"Cesarean sections account for roughly 25 percent of all deliveries. They have significantly reduced the infant and maternal morbidity and mortality associated with child birth," Dr. Hall said. "Even with these advances, risks include the risks of infection, bleeding and damage to internal, adjacent structures. "

But he said that the weaknesses of this study are important to note.

"These increased risks are reported as small and this study fails to control for possible confounding factors," he said. "As a result I am unable to support their findings as being clinically significant."

This study was published July 1 in the journal PLoS Medicine. The research was funded by the National Perinatal Epidemiology Centre in Cork, Ireland, and by Health Services Research. There were no conflicts of interest reported among the authors.

Review Date: 
June 30, 2014
Last Updated:
July 2, 2014