Navigation Links
Smoking-Low Birth Weight Link Explained in Part

Tobacco use narrows blood vessels to fetus, study finds

MONDAY, Feb. 2 (HealthDay News) -- A mechanism linking smoking during pregnancy to low birth weight has been identified by Danish researchers.

They found that smoking during pregnancy lowers production of an enzyme called endothelial nitric oxide synthase (eNOS), which regulates blood vessel dilation. Reduced production of eNOS causes narrowing of blood vessels and less blood flow to the fetus, resulting in lower birth weight, shorter length and smaller head circumference.

But the researchers also found that if women quit smoking early in pregnancy, eNOS levels return to normal, and infants are born at normal birth weight. The findings were published in the Feb. 2 online issue of Circulation.

"This study in one of the first to show a biochemical measurement of what is going on to cause the lower birth weight," said study author Malene Rohr Andersen, project manager of the Department of Clinical Biochemistry at Gentofte University Hospital.

"We have known for 50 years that infants born to mothers who smoke during pregnancy have lower birth weights. But this study provides a possible explanation of why there is restricted blood flow to the fetus. Reduced production of the vasodilator nitric oxide may lower the blood flow to the fetus," Andersen said in an American Heart Association news release.

The researchers looked at 266 healthy pregnancies of 182 nonsmokers, 43 smokers, and 41 women who stopped smoking at about six weeks into their pregnancy. The more cigarettes smoked per day, the lower the levels of eNOS concentration and activity.

The average difference in the newborn weight of infants born to nonsmokers and smokers was about 350 grams. Differences in eNOS activity accounted for about 25 percent of the birth weight reduction among infants born to smokers.

"Women who smoke should stop smoking if they plan to become pregnant, or at the very least should stop smoking as soon as they find out they are pregnant," Andersen said. "Women should also not start smoking again once they have delivered. Some women stop smoking during pregnancy, only to start up again after the baby is delivered, and the child is then exposed to environmental smoke, which also affects vascular function."

More information

The American Lung Association has more about smoking and pregnancy.

-- Robert Preidt

SOURCE: American Heart Association, news release, Feb. 2, 2009

Copyright©2009 ScoutNews,LLC.
All rights reserved

Related medicine news :

1. Another Reason Not to Smoke While Pregnant: Birth Defects
2. More than two-thirds of sexually active NYC youth use condoms, but other forms of birth control lag
3. Glades General Hospital First in Palm Beach County to Provide On-Site Electronic Birth Registration
4. Steroids Seem Safe for Babies at Risk of Early Birth
5. Many U.S. Women Unaware of Birth Defect Risks
6. Moms Low Cholesterol Tied to Preemie Births
7. IVF technique enables pregnancy without multiple births, Stanford researchers find
8. Fetal cell transplant could be a hidden link between childbirth and reduced risk of breast cancer
9. Sue Birth Control Companies for Your Health, Says American Life League
10. Maternal Mortality Declining in Middle-income Countries; Women Still Die in Pregnancy and Childbirth in Low-income Countries
11. UF researchers track genetic journey of HIV from birth to death
Post Your Comments:
(Date:11/24/2015)... ... ... American Family Care (AFC), the nation’s leading provider of urgent care and ... Metro Atlanta’s North Point Mall. The clinic is designed to test the concept of ... to operate through Dec. 24. , Holiday Pop-Up Clinic , Official Opening November 27, ...
(Date:11/24/2015)... CT (PRWEB) , ... November 24, 2015 , ... Aided ... (WCHN) today announced an innovative study designed to yield insights into how to detect ... development of biomarkers for pancreatic cancer from small, non-coding RNA molecules (ncRNA), genetic material ...
(Date:11/24/2015)... PALMYRA, Wis (PRWEB) , ... November 24, 2015 ... ... Process scholarship award at Cleveland University-Kansas City (CU-KC), in Overland Park, ... scholarship from Chiropractor and University President Carl S. Cleveland III on October 16. ...
(Date:11/24/2015)... ... November 24, 2015 , ... ... Exercise and Healthy Aging Program have announced their endorsement of the Medical ... Specialty Health Fitness is proud to have the MFN as one of our ...
(Date:11/24/2015)... Warsaw, IN (PRWEB) , ... November 24, 2015 , ... ... in his office to help the community stress less this holiday season. During ... unnecessary additional stress in people's lives and the team at AlignLife want to help ...
Breaking Medicine News(10 mins):
(Date:11/24/2015)... Nov. 24, 2015 Teledyne DALSA , a ... sensing technology, will introduce its CMOS X-Ray detector for ... November 29 to December 3, at McCormick Place in ... for diagnostic and interventional imaging will be on display in ... of advanced CMOS X-Ray detectors is the industry benchmark ...
(Date:11/24/2015)... Pa. , Nov. 24, 2015  NuShield, Inc., an industry leader in LCD screen protection ... and stationary computer technology as part of their patient monitoring or electronic documentation system. ... ... ... A ...
(Date:11/24/2015)... 2015  BioPlast Manufacturing, a manufacturer of plastic ... diagnostic and biotech environments, announced today that it ... petri dishes. This acquisition is aligned with BioPlast ... products that are designed and tested by scientists ... Bristol, Pennsylvania ...
Breaking Medicine Technology: