Smoking During Pregnancy Tied to Gestational Diabetes Risk
BETHESDA, MD -- January 28, 2005 -- Woman who smoke have a greater chance of developing gestational diabetes, a form of diabetes that first occurs during pregnancy, a new study suggests (Am J Epidemiol. 2004 Dec 15; 160(12): 1205-13). Gestational diabetes can lead to preeclampsia, a condition involving high blood pressure, protein in the urine, fluid retention, and swelling in the hands and feet. These women may also deliver very large babies (fetal macrosomia). In some cases, they continue to have diabetes (type 2 diabetes mellitus) in later years.
Pregnant Women In Preeclampsia Prevention Program Studied
The study analyzed records and medical tests from 3,602 pregnant women in a preeclampsia prevention program. The mean one-hour plasma glucose concentration was highest in women who smoked at the time of study enrollment, and lowest in women who had never smoked or who had quit smoking before or during pregnancy.
Heavy smokers who reduced their exposure had a lower plasma glucose concentration than those who did not. A three-hour oral glucose tolerance test showed that the proportion of women who developed gestational diabetes was lowest among those who had never smoked, intermediate among women who had quit before or during pregnancy, and highest among those who smoked at study enrollment.
The authors concluded that smoking during pregnancy is associated with decreased glucose tolerance and an increased risk of gestational diabetes. Reducing one's smoking level may modify these risks, although other factors such as diet and exercise may also be involved, they said. They suggested that more studies be done concerning the effect of smoking on the blood glucose levels of pregnant women.
Health Problems Caused by Smoking
Smoking has been associated with increased insulin resistance, altered glucose levels, and type 2 diabetes mellitus (Am J Public Health. 1993 Feb; 83(2): 211-4; BMJ. 1995 Mar 4; 310(6979): 555-9; and Diabetes Care. 2001 Sep; 24(9): 1590-5). Prior studies have been inconclusive as to whether or not tobacco is linked to gestational diabetes.
The use of tobacco during pregnancy often leads to premature births and low birth weights, which are leading causes of infant deaths (Surgeon General's Report, Reproductive Effects of Smoking). Smoking also causes cancers of the lung, bladder, esophageal, throat, kidneys, stomach, cervix, and pancreas as well as coronary heart disease and leukemia.
For more details about women and tobacco, see Women Smokers' Lung Cancer Risk Twice That of Men and Smoking Among Mothers of Young Children. Also see health benefits of quitting smoking, dangers of tobacco use, and Smokefree.gov for additional cessation information .