Featured Research

from universities, journals, and other organizations

Risk Of Preterm Birth Appears To Vary By Season; Women Who Conceive In Spring Are Most Vulnerable

Date:
February 5, 2007
Source:
University of Pittsburgh Medical Center
Summary:
Women who become pregnant in spring are more vulnerable to preterm birth than those who conceive in other seasons, according to researchers at the University of Pittsburgh. Results of perhaps the largest study of such seasonal variation in preterm birth, or birth prior to 37 weeks gestation, are being presented at the 27th annual meeting of the Society of Maternal-Fetal Medicine, being held Feb. 5-10 at the Hilton San Francisco and Towers in California.

Women who become pregnant in spring are more vulnerable to preterm birth than those who conceive in other seasons, according to researchers at the University of Pittsburgh. Results of a large study of such seasonal variation in preterm birth, or birth prior to 37 weeks gestation, are being presented at the 27th annual meeting of the Society of Maternal-Fetal Medicine, being held today through Saturday at the Hilton San Francisco and Towers in California.

"Preterm birth is a complex condition, and risk factors can change with the seasons," said Lisa Bodnar, Ph.D., M.P.H., R.D., assistant professor of epidemiology at the University of Pittsburgh Graduate School of Public Health (GSPH) and a co-author of the study.

Preterm birth affects some 12 percent of pregnancies in the United States, costing an estimated $26 billion, or $52,000 per infant, in medical care and lost productivity in 2005, according to the Institute of Medicine. And a recent study from the U.S. Centers for Disease Control and Prevention found that preterm birth contributed to more than a third of infant deaths -- twice as many as previously thought and making it the leading cause of infant deaths -- yet the underlying causes of premature birth remain poorly understood.

More than 500,000 babies are born too soon each year nationwide, and the preterm birth rate has increased more than 30 percent since 1981. Babies who do survive face the risk of cerebral palsy, mental retardation, chronic lung disease, and vision and hearing loss, as well as other developmental problems.

Researchers analyzed data from 75,399 deliveries over a 10-year period at the university-affiliated Magee-Womens Hospital of UPMC, grouping each by season of "last menstrual period," a date physicians historically have used to estimate conception. Women conceiving in summer had the lowest rate of preterm birth at 8.4 percent, with steadily increased rates for the fall (8.8 percent), winter (9.1 percent) and spring (9.2 percent).

Preterm birth prior to 32 weeks gestation, when complications can be more severe for mother and baby, also took place less often with conceptions in summer and fall than for those in winter or spring, the researchers noted. In fact, those conceiving in summer or fall had a 25 percent reduction in risk over those who conceived in winter or spring.

Tracking such disparities is a valuable way to target specific variables for further study, such as environmental allergens, dietary changes, sunlight exposure, viral infections and exercise habits, noted Hyagriv Simhan, M.D., assistant professor of obstetrics, gynecology and reproductive sciences at the University of Pittsburgh School of Medicine and study co-author.

"Everyone has heard that we 'put on an extra layer' in winter, and micronutrient intake shifts with the seasons," said Dr. Simhan. "We also know that inflammation plays a role. It could be that becoming pregnant when the immune system is primed by viral and bacterial exposures may be a factor weeks down the road."

"There have been studies in Africa of preterm birth in famine or non-famine seasons, but this is perhaps the most rigorous look at preterm birth rates by season in such a large population in an industrialized country," said Dr. Simhan.


Story Source:

The above story is based on materials provided by University of Pittsburgh Medical Center. Note: Materials may be edited for content and length.


Cite This Page:

University of Pittsburgh Medical Center. "Risk Of Preterm Birth Appears To Vary By Season; Women Who Conceive In Spring Are Most Vulnerable." ScienceDaily. ScienceDaily, 5 February 2007. <www.sciencedaily.com/releases/2007/02/070205110822.htm>.
University of Pittsburgh Medical Center. (2007, February 5). Risk Of Preterm Birth Appears To Vary By Season; Women Who Conceive In Spring Are Most Vulnerable. ScienceDaily. Retrieved April 25, 2014 from www.sciencedaily.com/releases/2007/02/070205110822.htm
University of Pittsburgh Medical Center. "Risk Of Preterm Birth Appears To Vary By Season; Women Who Conceive In Spring Are Most Vulnerable." ScienceDaily. www.sciencedaily.com/releases/2007/02/070205110822.htm (accessed April 25, 2014).

Share This



More Health & Medicine News

Friday, April 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Fungus Killing Bats, Spreading in US

Deadly Fungus Killing Bats, Spreading in US

AP (Apr. 24, 2014) A disease that has killed more than six million cave-dwelling bats in the United States is on the move and wildlife biologists are worried. White Nose Syndrome, discovered in New York in 2006, has now spread to 25 states. (April 24) Video provided by AP
Powered by NewsLook.com
Companies Ramp Up Wellness to Lower Health Costs

Companies Ramp Up Wellness to Lower Health Costs

AP (Apr. 24, 2014) That little voice telling you to exercise, get in shape and get healthy is probably coming from your boss. More companies are beefing up wellness programs to try and cut down their health care costs. (April 24) Video provided by AP
Powered by NewsLook.com
Blood From World's Oldest Woman Suggests Life Limit

Blood From World's Oldest Woman Suggests Life Limit

Newsy (Apr. 24, 2014) Scientists say for the extremely elderly, their stem cells might reach a state of exhaustion. This could limit one's life span. Video provided by Newsy
Powered by NewsLook.com
FDA Wants To Ban Sales Of E-Cigarettes To Minors

FDA Wants To Ban Sales Of E-Cigarettes To Minors

Newsy (Apr. 24, 2014) The Food and Drug Administration wants to crack down on the use of e-cigarettes, banning the sale of the product to minors. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins