Vaginal delivery as safe as cesarean for most early preterm births

August 6, 2012, Elsevier

Vaginal delivery for early preterm fetuses presenting head first, or vertex presentation, had a high rate of success with no difference in neonatal mortality compared to cesarean delivery, a new study published in the American Journal of Obstetrics and Gynecology reports. For breech births, however, the failure rate of vaginal delivery was high and planned cesarean delivery was associated with significantly lower neonatal mortality.

"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," says lead investigator Uma M. Reddy, MD, MPH, of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD. "For vertex-presenting fetuses less than 32 weeks' gestation, we saw no improvement in with a planned cesarean delivery."

Trials that attempt to randomize the route of delivery for women in preterm labor at high risk for delivery have not been feasible. Dr. Reddy and her colleagues used data from the Consortium on Safe Labor (CSL), a study conducted by the Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health. The CSL is a retrospective study collecting extensive data on over 200,000 deliveries between 2002 and 2008 from 12 clinical centers and 19 hospitals across the country.

The investigators first categorized the indications for preterm delivery: preterm labor, preterm premature rupture of membranes (PPROM), or fetal/maternal issues such as preeclampsia, placental abruption, or severe maternal medical disease. Maternal or fetal indications were responsible for 45.7% of early preterm deliveries, PPROM for 37.7%, and preterm labor for 16.6%. Preeclampsia and major congenital anomalies were the leading contributors to indicated early preterm births. The study then evaluated 2,906 singleton pregnancies between 24 0/7 weeks and 31 6/7 weeks eligible for either route of delivery. Attempted was compared to planned cesarean delivery. Data were analyzed based on gestational age blocks: 24 0/7 to 27 6/7 weeks and 28 0/8 to 31 67 weeks, based on the fact that the highest rates of neonatal mortality and morbidity occur 24 0/7 to 27 6/7 weeks.

Attempting vaginal delivery with vertex presentation at 24 0/7 to 27 6/7 weeks of gestation did not significantly affect neonatal mortality. More than 80% of the attempted vaginal births were successful. However, if the fetal presentation was breech, the majority of the deliveries were by planned cesarean delivery, and only 27.6% of attempted vaginal deliveries were successful.

Findings in the 28 0/7 to 31 6/7 weeks' gestation also differed by presentation. If the fetal presentation was vertex, the majority of attempted vaginal deliveries succeeded and there was no difference in the neonatal mortality rate compared with planned cesarean delivery. For breech-presenting fetuses, neonatal mortality was 6% for vaginal deliveries compared to 1.5% of the cesarean deliveries.

Dr. Reddy notes that previous studies examining the effect of route of delivery on neonatal mortality for early preterm births looked at the actual, not attempted, route of delivery. "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 applications and is crucial for counseling families about the benefit and risks of attempting vaginal in this situation," she concludes.

Explore further: Study finds in women with prior cesarean, optimal gestational age for elective delivery is week 39

More information: “Neonatal Mortality by Attempted Route of Delivery in Early Preterm Birth” by U.M Reddy, J. Zhang, L. Sun, Z. Chen, T.N.K. Raju, and S.K. Laughon (doi 10.1016/j.ajog.2012.06.023.), American Journal of Obstetrics & Gynecology, Volume 207, Issue 2 (August)

Related Stories

Study finds in women with prior cesarean, optimal gestational age for elective delivery is week 39

February 10, 2012
In a study to be presented today at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting, in Dallas, Texas, researchers will report findings that indicate that for women with prior delivery via ...

Researchers pinpoint reasons for dramatic rise in C-sections

June 22, 2011
(Medical Xpress) -- In one of the first studies to examine the reasons for the rising number of women delivering their babies by cesarean section, Yale School of Medicine researchers found that while half of the increase ...

Vaginal progesterone reduces preterm birth, neonatal morbidity and mortality in women at risk

December 14, 2011
Women with a short cervix should be treated with vaginal progesterone to prevent preterm birth, according to a landmark study by leading obstetricians around the world. Vaginal progesterone decreased the rate of preterm birth ...

Recommended for you

Premature births linked to changes in mother's bacteria

January 23, 2018
Changes to the communities of microbes living in the reproductive tract of pregnant women could help to spot those at risk of giving birth prematurely.

Essure female sterilization device appears safe: study

January 23, 2018
(HealthDay)—Essure implants used in female sterilization have come under fire in recent years, with women reporting a wide array of problems to the U.S. Food and Drug Administration.

Study shows how fetal infections may cause adult heart disease

January 23, 2018
Recent studies have shown that infants born prematurely have a higher risk of developing heart disease later in life. Now, a study led by researchers at the University of Washington School of Medicine in Seattle shows that, ...

Rise in preterm births linked to clinical intervention

January 18, 2018
Research at the University of Adelaide shows preterm births in South Australia have increased by 40 percent over 28 years and early intervention by medical professionals has resulted in the majority of the increase.

New report calls into question effectiveness of pregnancy anti-nausea drug

January 17, 2018
Previously unpublished information from the clinical trial that the U.S. Food and Drug Administration relied on to approve the most commonly prescribed medicine for nausea in pregnancy indicates the drug is not effective, ...

New study finds 'baby brain' is real, but the cause remains mysterious

January 15, 2018
So-called "baby brain" refers to increased forgetfulness, inattention, and mental "fogginess" reported by four out of five pregnant women. These changes in brain function during pregnancy have long been recognised in midwifery ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.