ORLANDO – Infants with congenital heart disease generally do not benefit from scheduled delivery by either induced labor or an elective cesarean delivery, based on a review of 329 infants managed recently at a single, U.S. referral center.
But despite a lack of documented benefit from scheduled delivery and the potential for impaired infant health from scheduled delivery, the practice appeared common in Southern California, with a significantly reduced rate of spontaneous labor and vaginal deliveries for infants with a prenatal diagnosis of congenital heart disease.
"We speculate that the potential advantages derived from the prenatal diagnosis of congenital heart disease and from a controlled delivery during regular hours may be offset by the known neonatal risks associated with unnatural delivery, such as impaired lung dynamics and impaired clearance of lung fluid following a cesarean section," said Dr. Luca U. Trento at the annual scientific sessions of the American Heart Association.
"In certain cases, for example, neonates expected to require emergency intervention shortly after birth such as a child with a restricted atrial septum, scheduled delivery may be indicated. Furthermore, a mother who lives a far distance from the delivery center is another reason to consider scheduled delivery. However, on the whole our data do not support empiric modification of the delivery plan based solely on prenatal diagnosis of congenital heart disease," said Dr. Trento, a pediatric cardiologist with Kaiser Permanente of Northern California in Roseville.
"Routine cesarean sections are probably detrimental to both the baby and the mother. We are not saying never do a scheduled delivery, but a fetal diagnosis of congenital heart disease is not enough reason to alter the delivery mode," he said. Dr. Trento reported data collected at Children’s Hospital Los Angeles that he analyzed when he was on staff there.
His retrospective analysis included 329 consecutive infants with congenital heart disease admitted to the hospital for a planned cardiac intervention during the first 30 days of life and with an identified mode of delivery. The delivery mode was spontaneous labor for 54%, scheduled cesarean delivery for 34%, and induced labor for 12%. The average gestation age of the infants in all three subgroups was about 38 weeks, their average birth weight was about 3,000 g, and their average APGAR scores were 7.5 at 1 minute and 8.5 at 5 minutes.
Prenatal diagnosis of congenital heart disease occurred for 45% of the infants. Among those delivered by spontaneous labor, 33% had a prenatal diagnosis; among children born by cesarean section, 51% had a prenatal diagnosis; and 80% of infants with an induced delivery had a prenatal diagnosis.
Among the 58 infants diagnosed prenatally who nonetheless were scheduled for delivery by spontaneous labor, 55% underwent vaginal delivery while 45% had a cesarean delivery. In contrast, among the 119 infants scheduled for delivery by spontaneous labor with their congenital disease unidentified prenatally, 73% underwent vaginal delivery and 27% converted to cesarean delivery. The difference between the two subgroups was statistically significant.
"A fetal diagnosis of congenital heart disease is not enough reason to alter the delivery mode."
"This demonstrates some sort of bias on the obstetric side when there is a known prenatal diagnosis of congenital heart disease that increases the rate of cesarean section," Dr. Trento said.
In a multivariate analysis, prenatal diagnosis of congenital heart disease linked with a statistically significant, 2.6-fold increased rate of scheduled delivery, either induction or cesarean. Other tested variables showed no linkage to scheduled delivery including the specific anatomic type of congenital heart disease, gestational age, or any extracardiac malformation.
A second analysis looked at a variety of outcomes among the infants studied, including rate of preoperative intubation, survival to surgery, duration of stay in the cardiothoracic intensive care unit, survival to postoperative discharge from the cardiothoracic intensive care unit, and survival to hospital discharge. This analysis revealed no statistically significant link between delivery mode and any of these outcomes. Other variables not linked with these outcomes included gestational age, being small for gestational age, a prenatal diagnosis of congenital heart disease, and delivery during "regular" hours of 8 a.m. to 6 p.m. Monday through Friday. The only significant predictor of survival to hospital discharge in a multivariate analysis was the infants’ risk adjusted congenital heart surgery score. Infants with a score of 3 or 4 had a 2.2-fold higher rate of surviving to hospital discharge, compared with infants with a score of 5 or 6.
Dr. Trento said that he had no disclosures.