November 7, 2007 – Researchers fear that there are more cases of uterine rupture during natural childbirth in women who have had a previous Caesarean section, mainly because of the growing number of this type of procedure.
This complication – rare, but serious – affects nine out of 1,000 women (almost 1%) among those who naturally give birth to a second child after having their first by caesarean section. In those who have not had a caesarean, this risk is only 0.18 in 1,000.
These data come from a recent study of 300,200 second child births in Sweden from 1992 to 2001.
During these deliveries, 227 women suffered a uterine rupture. Among them, 14 lost their babies, which represents a death rate at birth of 51 per 1,000. This proportion is 1.4 per 1,000 among women who did not experience a rupture during the second childbirth in following a cesarean section.
According to the study authors, there are factors that may explain why a scar on the uterus can tear during childbirth:
- induction of labor with a medicine (prostaglandin E2, for example);
- mother’s age (over 35);
- the child’s weight (over 4 kg or 8.8 pounds).
In Canada, the caesarean birth rate is constantly changing: from 17% in 1993-1994, it was 26% in 2005-2006. This is less than in the United States and Australia (29%, in 2004), but more than England (24%, in 2005-2006). The World Health Organization (WHO) recommends performing caesarean sections in only 15% of all deliveries2.
A risk known to obstetricians
In February 2005, the Society of Obstetricians and Gynecologists of Canada (SOGC) issued recommendations3 for patients who have had a Caesarean section to prevent uterine rupture during a subsequent delivery.
The SOGC is insisting that doctors discuss the risks of a vaginal birth with their patients who have had a cesarean delivery before. However, she recalls that, in most cases, “a vaginal birth can be successful in complete safety for both mother and child”.
According to the SOGC, only the fact of having had a so-called “classic” cesarean section, with a vertical incision, as well as a cesarean section with an inverted “T” -shaped incision, constitutes a specific contraindication to a patient. vaginal birth. In this case, the risk of uterine rupture is 4% to 9%, compared to 0.2% to 1.6% for other types of incisions.
Nevertheless, the organization suggests that its members recommend that women who have had a previous Caesarean section deliver in a hospital, where emergency surgery can be performed quickly if complications arise.
Martin LaSalle – PasseportSanté.net
1. Kaczmarczyk M, Sparén P, Terry P, Cnattingius S, Risk factors for uterine rupture and neonatal consequences of uterine rupture: a population-based study of successive pregnancies in Sweden, BJOG, October 2007, Vol. 114, no 10, 1208-14.
2. Canadian Institute for Health Information (CIHI), Giving Birth in Canada: Regional Trends 2001-2002 to 2005-2006, Analysis released July 25, 2007. The PDF document is available at www.cihi. ca / cihiweb / en [consulté le 14 novembre 2007].
3. Martel MJ, MacKinnon CJ, et al, Guideline on Vaginal Birth in Previous Cesarean Patients, SOGC Clinical Practice Guidelines, February 2005, No 155, 175-188. The document in PDF format is available at www.sogc.org [consulté le 6 novembre 2007].
