The study, published in the April 3, 2008, issue of the New England Journal of Medicine, is the first to document the effect of obesity during pregnancy on the use of health care services.

The study looked at pregnancies within numerous categories: three obese categories (obese, very obese and extremely obese) along with underweight, normal weight and overweight. Using data from 13,442 pregnancies that resulted in a live birth or stillbirth between 2001 and 2004, researchers found that, compared with pregnant women of normal weight, obese pregnant women had longer hospital stays and more obstetrical ultrasounds, used more outpatient medications, and were more likely to be seen by physicians rather than nurse midwives and nurse practitioners.

"The increased health care use by obese pregnant women will have substantial cost implications," explained Susan Chu, Ph.D., lead scientist on the study. "About one in five women who give birth in the United States is obese, which means that of the four million births each year, about one million are to obese women. Thus even a small increase in utilization associated with obesity will have considerable economic impact."

For instance, for prenatal visits with a physician, normal women had an average of about four visits, while very obese and extremely obese women had five and six visits. The primary reasons for the increased utilization of these services were increases in Caesarean section and obesity-related high risk conditions. Caesarean delivery rates were 45.2 percent for extremely obese women, compared to 21.3 percent for normal weight women.

Given the health and economic costs, the importance of preventing obesity in women of child-bearing age in order to enhance health during pregnancy and throughout the course of life still remains a vital public health concern.

The study findings are consistent with previous reports that demonstrated that obesity during pregnancy is associated with serious pregnancy-related complications, such as high blood pressure, gestational diabetes which occurs in a woman who develops diabetes during her pregnancy, and Caesarean deliveries.

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