Effects of Cesarean Sections on Future Pregnancies

Many women are aware of the associated risks of having a cesarean delivery. However, what some women may be unaware of is the fact that having a cesarean can increase your risk for a number of complications in your next pregnancy. While some of these risks have been noted before, a recent study from Australia has shown that women may be in more danger than they realize.

Research Basics
Certain factors, such as an increased risk of stillbirth in future pregnancies, have been documented by previous studies examining how a c-section can impact a woman in later pregnancies. A new study from Australia, though, has found evidence that it may not just be stillbirth women need to worry about.

For their research, investigators examined medical data on all births in New South Wales between 1994 and 2002. Narrowing down their focus, researchers identified 136,101 women with one previous birth who also had a singleton birth between 1998 and 2002. From this group of women, almost 20% had a cesarean section. However, the information the investigators analyzed did not state why the c-sections were performed. Therefore, it is unknown how many of the cesarean sections were done for medical reasons and how many, if any, were an elective cesarean.

Findings
In all of the mothers, investigators looked for the following complications:

• Uterine rupture
• Hysterectomy
• Postpartum hemorrhaging
• Complicated postpartum hemorrhaging
• Postpartum infection
• Admission to intensive care
• Manual delivery of the placenta

Researchers also examined whether there were any complications with the infants. The main outcomes investigators took note of included:

• Neonatal death
• Infant death
• Admission to neonatal intensive care
• Small for gestational age
• Respiratory distress syndrome
• Bacterial sepsis
• Preterm delivery

While women who had given birth vaginally in their first pregnancy experienced many of these complications in their second pregnancy, women who had given birth via c-section in their first pregnancy were more likely to have complications in a subsequent pregnancy.

Most notably, researchers found that half of all uterine ruptures, one in five hysterectomies and a third of all postpartum infections experienced by the women were attributable to having had a cesarean section in a previous pregnancy. Moreover, 5% of babies admitted to neonatal intensive care and 4% of babies born prematurely were attributed to a previous c-section.

Those women who appeared to be most at risk were those attempting a VBAC (Vaginal Birth after Cesarean). The reason for this, investigators suggested, was likely abnormal placentation, a condition associated with cesarean scarring. Conversely, women who had a planned c-section in their second pregnancy were less likely to have complications, likely because there was nothing "wrong" with their health.

What Does This Mean?
While it is easy to get alarmed at this significant increase in complications during pregnancy, researchers were quick to point out that, although a previous cesarean section did put a woman at more risk, these complications were still fairly rare. Additionally, because the reasons why a woman had a cesarean section in her first pregnancy were never provided to researchers, further investigation is necessary to see whether these increased risks will vary according to why a c-section was performed.

Nevertheless, compared to women who deliver vaginally, having a c-section in your first pregnancy does appear to amplify your likelihood of developing certain complications in your second pregnancy. For this reason, women who are considering having an elective c-section need to be sure that they are aware of the risks to themselves and their children, not just in their current pregnancy, but also in future pregnancies.