Infants Born After 40 Weeks Gestation Have a Higher Risk of Impaired Health, Death

To print: Select File and then Print from your browser's menu
---------------------------------------------------------------------------------------
Title: Infants Born After 40 Weeks Gestation Have a Higher Risk of Impaired Health, Death
URL: http://www.pslgroup.com/dg/22E542.htm
Doctor's Guide
October 7, 2008

SAN FRANCISCO -- October 7, 2008 -- Infants born more than 1 week past their due dates have a higher risk of both impaired health and death, according to 2 new studies published in the October issue of the American Journal of Obstetrics and Gynecology.

The 2 studies focused on different elements of the risk of progressing beyond 41 weeks of gestation, but held similar conclusions.

The first study, which followed 1.8 million normal births in California from 1999 to 2003, reported greater odds of infant death within 28 days among those born at 41 and 42 weeks. The second study examined 2.5 million low-risk births nationwide in 2003 and reported that the risk of caesarean deliveries and poor health outcomes for both mother and child increased at 40 weeks and beyond.

"Significant research has focused on the risks of premature deliveries, but until now, there have been no large-scale studies documenting the increased risk of delivering at 40 weeks or more," said senior author Aaron Caughey, MD, University of California San Francisco (UCSF) Medical Center and UCSF School of Medicine, San Francisco, California.

"Combined, these 2 papers provide very compelling evidence of the importance of closely monitoring pregnancies beyond 40 weeks and possibly intervening to prevent complications to both mother and child."

Dr. Caughey said a growing number of studies have pointed to increased pregnancy complications and stillbirths at 41 weeks or even earlier. Both of these studies confirm that the risk of caesarean deliveries and poor maternal or child outcomes starts to increase as early as 40 weeks.

The second study used national birth registries through the Centers for Disease Control and Prevention to analyse all low-risk pregnancies resulting in live, full-term deliveries between 37 and 42 weeks gestation in the United States in 2003. The study eliminated births to women with pre-existing medical conditions, such as cardiac disease or gestational diabetes, as well as women who had previously had a child delivered by caesarean section.

The national study found that women who delivered beyond their due date had an increased chance of caesarean section or operative delivery versus those who delivered at 39 weeks. Compared with delivery at 39 weeks, women who delivered at 41 weeks had a 40% higher chance of having a caesarean delivery. That correlates to a higher risk of haemorrhage and other complications for the mother.

Infants delivered at 41 weeks also had a higher risk of injury during birth, as well as nearly twice the rate of having meconium in the amniotic fluid as infants born at 39 weeks.

"These are among the largest studies ever published that examine the complications of full-term pregnancy by week of gestation," said lead author Yvonne W. Cheng, MD, UCSF and University of California Berkeley School of Public Health, Berkeley, California. "Both were consistent with prior studies in showing that delivery at 39 weeks seems to be associated with the lowest risk to both mother and child."

SOURCE: University of California San Francisco

http://www.docguide.com

Return to News Story Page

webmaster@pslgroup.com