The more obese a woman is, the greater her risk of having a stillbirth.

Obese women are more likely than their normal-weight counterparts to have a stillbirth, and the risk appears to rise with the degree of a woman's obesity. Overall, Missouri women who gave birth between 1978 and 1997 were about 40% more likely to have a stillbirth if they were obese than if they were normal-weight; the risk of stillbirth was elevated by 30% for women at the low end of the obese range, but was nearly doubled for the extremely obese.
The general pattern of increasing risk with more severe obesity held for both black and white women, but the differentials were greater for blacks in every category. Given a "persistent surge" in extreme obesity among women, and well-established connections between obesity in general and poor birth outcomes, researchers set out to explore the relationships between stillbirth risk and degrees of obesity. They used linked data files from Missouri's vital statistics system to study maternal characteristics and birth outcomes associated with singleton pregnancies of 20-44 weeks' gestation. After calculating women's prepregnancy body mass index (or BMI, defined as weight in kilograms divided by the square of height in meters), they categorized women according to the following weight categories: normal (BMI, 18.5-24.9), class 1 obesity (30.0-34.9), class 2 obesity (35.0-39.9) and extreme obesity (40.0 or higher). (Women who were underweight or who were overweight but not obese were excluded.)
Stillbirth was defined as in utero fetal death at 20 or more weeks' gestation; the researchers computed stillbirth rates, compared them across maternal characteristics by using chi-square tests and used Cox hazards regression to assess risk factors. Approximately 1.4 million mother-fetus pairs were included in the analyses. Nearly 10% of women were obese: Six percent were at the low end of the obesity range, 2% were in the middle and 1% were at the high end. The proportion who were obese was higher among black women than among whites-13% vs. 9%. Obese women were more likely than those of normal weight to be at least 35 years old, multiparous and black; they had had more schooling than normal-weight women and were more likely to have received adequate prenatal care. Normal-weight women were more likely than their obese counterparts to be married and to smoke.
Source: Perspectives on Sexual and Reproductive Health, March, 2009 by D. Hollander

Sexual behavior of single adult American women

In contrast to the intense public discussion and concern regarding adolescents' sexual behavior and reproductive health needs, limited attention has been given to the sexual behavior of single adult women. However, demographic shifts in the United States make the behavior and needs of this group increasingly salient. The median age at first marriage rose from 22.0 years in 1980 to 25.3 years in 2002; as of 2002, 40% of women aged 25-29 had never married. Cohabitation is becoming a common alternative to marriage, and the relative impermanency of both marriage and cohabitation means that a woman may be single at different periods in her lifetime. Sexual activity among single women puts them at risk of unplanned pregnancy, unplanned births and STDs, including HIV, and determines the extent of their need for sexual and reproductive health information and services. Given the less stable nature of single women's sexual relationships, their needs for services may be greater than those of married or cohabiting women.
A better understanding of single women's sexual and reproductive lives is required to inform public policies that address their behaviors and needs. "Abstinence until marriage" has been a foundation of federal policy for the past decade, but more recently, an unprecedented emphasis on promoting abstinence among people in their 20s has developed. Guidelines for the $50 million federal abstinence education grant program to states have expanded the target population to include unmarried adults up to 29 years old. Programs utilizing these funds are required to teach that sex among unmarried adults is not only nonnormative, but also unhealthy and destructive, and likely to cause harmful physical and psychological effects.
Given demographic trends and the growing policy interest in single women, it is important to understand the sexual behavior of single adult American women, including how it compares with that of married and cohabiting women. While marital and union status is often used as a differentiating variable in studies of sexual behavior, it generally is not the focus of these studies; as a result, information about the sexual behavior and reproductive health needs of single women is scattered across diverse studies.

Source: Perspectives on Sexual and Reproductive Health, March, 2009 by Laura Duberstein Lindberg, Susheela Singh