New Study Confirms Cesarean Risks

Main Category: Nursing / Midwifery
Also Included In: Women's Health / Gynecology;  Pregnancy / Obstetrics
Article Date: 08 Apr 2006 - 0:00 PST

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A study just published by the journal Obstetrics & Gynecology confirms that birth by cesarean increases risks of two life threatening problems in future pregnancies. The conditions, called placenta abruption and placenta previa, involve the way the placenta attaches to the inner lining of the uterus.

In a cesarean birth a surgical incision is made in the uterus causing a permanent scar. This scarring of the uterine muscle can affect the way the placenta attaches to the uterus in future pregnancies.

Placenta abruption is the premature separation of all or part of the placenta prior to the birth of the child. This decreases the baby's oxygen supply and can cause blood loss in the mother, baby or both. If the abruption involves a large enough area, emergency cesarean birth may be required to save the life of mother and baby. Abruptions can occur anytime in pregnancy, even when the baby is still premature, further increasing danger to the newborn.

Placenta previa is abnormal growth of the placenta over all or part of the uterus' natural opening to birth canal, or cervix. This causes damage to the placenta and severe blood loss during labor. Bleeding is also more likely to occur before labor and without warning. Women with placenta previa always require cesarean delivery prior to labor.

It is not fully understood why scars on the uterus cause these problems. Several studies in recent years have confirmed the connection between cesareans and abnormal placental attachment. The new study is one of the first to confirm a direct relation ship between the number of surgeries and the amount of risk. By reviewing over 150,000 first, second and third pregnancies, it found the risk of both complications rising as the number of surgeries increased.

Together these two problems complicate about 60,000, or 1-2 percent, of pregnancies in the U.S. yearly. In addition to cesareans, factors such as cigarette smoking, cocaine use and maternal age have also been associated with the disorders. But cesarean section is the most common surgery performed in the U.S. and has risen sharply in recent years. Since 1970 the percentage of mothers giving birth by cesarean has risen from 5% to 29% in 2003. Contrary to expectation, this has not resulted in safer births or healthier patients. Complications from the surgery are expected to grow as it becomes more common.

Other risks associated with cesarean birth are rupturing the scar in future pregnancies, increased rates of infection and blood loss, more breathing problems in newborns, less successful breastfeeding, longer healing time, longer hospital stays and more hospital re admissions.

Yet obstetricians the world over are ambivalent about cesarean birth. In surveys form the U.S., Europe, Canada, and South America, upwards of 50% of practicing OB/Gyns favor even more liberal use of cesareans. Some feel more protection against lawsuits with cesareans. Others point out that normal vaginal births also have risk, and some perceive consumer demand for "patient choice" cesarean. Recent surveys of American women find the public demand for medically unnecessary cesarean at less than 1 percent. Professional organizations tend to focus on the difference between accommodating true patient demand and creating demand, and upon accurate presentation of risk. The new study adds to the argument that unnecessary cesarean should be avoided, since the procedure creates risk in future pregnancies, and most women who have children have more than one, whether planned or not.

Also debated is whether women should be encouraged or even permitted to attempt a normal birth once a cesarean has been preformed. Recent research has suggested that vaginal birth after cesarean, or VBAC, carries risks of rupturing the old scar, another potentially life threatening complication. The new study suggests that VBAC may be beneficial if more pregnancies are planned, or if plans are uncertain.

By Patrick Thornton, CNM

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