First of two parts
SATURDAY, May 11, 2002 (HealthDayNews) -- As the warm weather arrives, more than tulips may start to bloom. Experts say a baby boom is on the way and, as surprising as it may seem, the Sept. 11 tragedy is one of the primary reasons why.
Whether it be to cement immortality or simply stop putting off for tomorrow what can be done today, there seems to be no question that, beginning in July, more babies will be born.
However, while world leaders continue to urge people to resume their normal lives, medical experts warn that any newfound desire to create or expand a family comes with a price in these troubled times.
That price is increased stress, a particular problem for pregnant women.
Among it's most detrimental effects: an increased risk of premature labor and premature birth.
"These are real and credible threats that have been linked to stress. For some pregnant women, stress can cause a variety of concerns, particularly increasing their risk of premature birth," says Dr. Michael Paidas, director of Maternal Fetal Medicine at New York University Medical Center.
Indeed, a study in the American Journal of Epidemiology found that both anxiety and depression can increase a mother's risk of premature labor. This, say a group of French researchers, is particularly true if the woman also experiences physical problems during her pregnancy, such as vaginal bleeding, or if she fails to gain enough weight during pregnancy.
This new study underscores earlier findings from the University of California, where researchers learned that women who experience any type of extreme psychological stress during the early part of their pregnancy were up to three times more likely to deliver prematurely.
Experts warn that premature birth is not only associated with a higher risk of infant mortality, but, should the child survive, an increased risk of delayed motor development, cognitive impairment and emotional and social problems for the child.
In addition, "premature babies are often low birth weight," says Dr. Stephen Chasin, director of High Risk Pregnancy at Weill Cornell Medical Center in New York City. This, he says, can be another factor that contributes to developmental delays.
Studies have also shown that even when babies are born on schedule, they can still be dramatically underweight if the mother experiences significant stress during the pregnancy.
Just because you sail through your first three months without problems, experts say you're still not safe. Among the very latest research: Studies that link high anxiety during the third trimester of pregnancy with an increased risk of autism, a serious neurological disorder that can affect a child's ability to communicate and learn.
For Dr. David Beversdorf, who published the new research, the most dangerous time to experience stress appears to be between the 24th and 28th weeks of pregnancy.
"Perhaps not coincidentally, this coincides with a period of time when a particular area of the brain known as the cerebellum is developing -- an area that has been shown to be structurally different in children with autism," says Beversdorf, an assistant professor of neurology at Ohio State University Medical Center.
However, the baby isn't the only one who can suffer as a result of high anxiety. A group of Finnish researchers found that stress in early pregnancy may increase a mother's risk of preeclampsia, a potentially life-threatening form of high blood pressure considered dangerous for mother and child alike.
While doctors still aren't certain why or even how stress affects pregnancy, Paidas believes a series of hormones may hold the key. Among the most important is corticotropin-releasing hormone (CRH).
Produced by the brain and the placenta, CRH prompts the body to release prostaglandin, a second hormone that triggers uterine contractions and ultimately starts the labor process.
"When levels of CRH go up as a result of stress, labor can begin long before baby is due," Paidas says.
Indeed, a 1999 study conducted by the University of California at Los Angeles School of Medicine found that women who experienced high levels of stress during certain periods of their pregnancy were also likely to have high levels of CRH.
What To Do
While it's clear that stress can influence pregnancy, doctors say it's vital to remember no two women experience stressful events in the same way.
"How a woman reacts is highly individualized, so it is definitely not fair or correct to say that all women who experience stress during their pregnancy will affect the health of their baby, because this just isn't true," Paidas says.
More important, experts say, is that even women who experience extremely stressful reactions during pregnancy can offset the threat of problems by taking a few simple steps to reduce their anxiety.
Learn more about how stress affects pregnancy by visiting The March of Dimes, or the University of California, Irvine.
Tomorrow: Steps pregnant women can take to reduce their levels of stress.
