According to a recent study published in the American Journal of Obstetrics and Gynecology, babies presenting vertex position (head first) born by vaginal delivery have equally as successful birth rates as those born by cesarean delivery (C-section). However, the researchers noted that preterm breech births by vaginal delivery are not successful, and C-sections are much more practical for these types of births, in order to avoid neonatal mortality.

Lead author of the study, Uma M. Reddy, MD, MPH, from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health in Bethesda, MD commented:

“Selecting a route of delivery at less than 32 weeks’ gestation is a difficult clinical decision given the high rate of infant mortality and morbidity as well as the maternal risks associated with cesarean delivery. For vertex-presenting fetuses less than 32 weeks’ gestation, we saw no improvement in neonatal mortality with a planned cesarean delivery.”

The authors analyzed data from the Consortium on Safe Labor (CSL), which includes information from over 200,000 deliveries from 2002 to 2008 which took place at 19 hospitals and 12 clinics all over the country.

They used this data because previous studies which tried to analyze randomized preterm deliveries have not been successful.

Preterm delivery was classified as being necessary due to preterm rupture of membranes (PPROM), preterm labor, fetal or maternal issues such as: preeclampsia, severe maternal medical disease, or placental abruption.

According to the study, fetal or maternal factors accounted for 45.7% of deliveries in early term, PPROM accounted for 47.7% and pre-term labor 16.6%

Major congenital abnormalities and preeclampsia accounted for the majority of early preterm births.

The researches analyzed 2,906 pregnancies – between 24 /07 weeks and 31 6/7 weeks weeks, which had the options of either vaginal or cesarean delivery. They compared planned cesarean delivery with vaginal delivery.

The data was looked at by age blocks: 24 0/7 to 27 6/7 weeks and 28 0/8 to 31 6/7 weeks because the neonatal mortality seemed to occur at 24 0/7 to 27 6/7 weeks.

Vaginal deliveries, with vertex presentation and attempted at 24 0/7 to 27 6/7, had no dramatic affect on neonatal mortality, and 80% of the births had positive outcomes.

On the other hand, breech presentation resulted in planned cesarean deliveries for the most part and of the vaginal deliveries performed, only 27.6% were successful.

Deliveries during 28 0/7 to 31 6/7 weeks’ gestation also resulted in different outcomes, depending on presentation. Once again, for vertex presentation most deliveries were successful – with no difference found between planned cesarean deliveries and neonatal mortality rates.

Neonatal mortality was 6% for vaginal deliveries and 1.5% of cesarean deliveries when the presentation was breech during the 28 0/7 to 31 6/7 weeks’ gestation.

Dr. Reddy concluded:

“The detailed information in our study, not available in birth certificate data, enabled us to account for the effect of attempted route of delivery and indications for delivery on neonatal mortality. This information has direct clinical applicationg and is crucial for counseling families about the benefits and risks of attempting vaginal delivery in this situation.”

Written by Christine Kearney