Start Antibiotics Prior to C-Section Incision : Data show this significantly reduces maternal infections, does not appear to harm newborns.


From Obstetrics & Gynecology

Antimicrobial prophylaxis now should be given within 60 minutes of the start of a cesarean delivery, rather than after cord clamping,

The recommended change in practice comes from a new opinion by the American College of Obstetricians and Gynecologists' Committee on Obstetric Practice as Committee Opinion No. 465 (Obstet. Gynecol. 2010;116:791-2).

“Based on the latest data, prophylactic antibiotics given to pregnant women before a cesarean significantly reduce maternal infections and do not appear to harm newborns,” Dr. William H. Barth Jr., chair of the committee, said in a statement.

“Anytime you have invasive surgery, you have an increased risk of developing an infection at the incision site,” he said. Infection is the most common complication of cesarean delivery and can occur in an estimated 10%-40% of women who undergo cesarean delivery, compared with 1%-3% of women who deliver vaginally, according to ACOG.

The committee recommends antimicrobial prophylaxis for all cesarean deliveries unless the patient is already receiving appropriate antibiotics. When it is not possible to begin administration within 60 minutes of the first incision—as with emergent delivery—prophylaxis should be administered as soon as possible.

Antimicrobial prophylaxis has been a common practice for cesarean deliveries. However, intraoperative antibiotics have been administered after umbilical clamping due to concerns about neonatal exposure to antibiotics. In particular, it has been theorized that antibiotics in neonatal serum could mask positive bacterial culture results in newborns and that fetal antibiotic exposure could lead to increased newborn colonization or infection with antibiotic-resistant organisms.

Older studies had suggested that when prophylactic antibiotics were given before the cesarean, pediatricians tended to do more invasive neonatal sepsis evaluations and costs were increased, Dr. Barth said in an interview. “This was based on the fear that the antibiotics given to the mother would cross rapidly to the fetus and then mask the signs of infection in the newborn child.” Pediatricians feared that the usual signs of sepsis might be masked by these antibiotics. Given this fear, tests such as blood draws and lumbar punctures that are useful in making a diagnosis of newborn sepsis tended to be used more frequently.

“However, based on recent randomized clinical trials and systematic reviews, giving the mother the antibiotics before the cesarean incision does not appear to increase problems in the newborn. None of the studies were large enough to say that definitively, but given the overall benefit to the mother, our committee—which included pediatricians—felt that this was the right thing to do,” said Dr. Barth, chief of maternal-fetal medicine at Massachusetts General Hospital, Boston.

In fact, preoperative antimicrobial prophylaxis “does not appear to have any deleterious effects on mother or neonate,” the committee wrote. Timing really does make a difference. In the studies reviewed, preoperative administration significantly reduced the rates of endometritis and total maternal infectious morbidity, compared with administration after cord clamping. Just as importantly, preoperative administration was not associated with an increase in neonatal infectious morbidity or the selection of antimicrobial-resistant bacteria causing neonatal sepsis.

The committee recommends that the infusion be timed so that a bactericidal serum level is reached by the time of skin incision. Therapeutic antibiotic levels should be maintained throughout the operation. Readministration is indicated at intervals of one or two times the half-life of the drug during longer procedures. The committee recommends using narrow-spectrum drugs that are effective against gram-positive and gram-negative bacteria and against some anaerobic bacteria – such as first-generation cephalosporins. Notably, obese women may require doses larger than the recommended 1 gram intravenous cefazolin (with a therapeutic dose maintained for 3-4 hours). Clindamycin with gentamicin is an acceptable alternative for women with significant allergies to beta-lactam antibiotics.

Disclosures: Dr. Barth said he had no conflicts of interest to disclose.

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