On the basis of this literature, we hypothesized that pregnant smokers and women with smoking partners U0126 would be more likely to have household members, relatives, friends, and coworkers who smoked. Moreover, in addition to women’s own smoking status, we expected partner smoking to be a significant predictor of frequency of SHS exposure. We expected that reliance on partner smoking alone would misclassify a number of pregnant women who were exposed to SHS as having no SHS exposure. Given the increased media focus on the negative effects of SHS in recent years, we expected general declines in frequency of SHS exposure across pregnancy. Methods Sample Selection Pregnant women who presented for prenatal care at a large city hospital were asked to complete a self-report screening form at their first prenatal appointment.

Women who met initial eligibility criteria were invited to participate in an ongoing prospective study of maternal health and child development. Initial eligibility criteria included the following: less than 20 weeks gestation, maternal age of 18 years or older, no illicit drug use (other than cannabis), no heavy alcohol (more than one drink per day or four drinks on one occasion) or cannabis consumption (more than one joint per day or four joints on one occasion) after pregnancy recognition, and no multiple births. Women who agreed to participate were scheduled for a total of four interviews: a prenatal interview at the end of each trimester and a postnatal interview at 2 months of infant age.

Once a pregnant smoker was recruited into the study and had completed the first prenatal interview, the most similar nonsmoking woman with regard to age and education was recruited. The study protocol was approved by the appropriate institutional review board. Participants were informed that data confidentiality was protected by a Federal Certificate of Confidentiality issued by the National Institute on Drug Abuse. Demographic Characteristics The average age of the women was 24.2 years (SD = 4.9 years) at the time of their first prenatal interview. The sample was 46% African American, 20% Hispanic, 26% Caucasian, and 8% other or mixed Brefeldin_A race. Fifty-eight percent of the women were married or living with their partner, while the remainder of the sample reported being in a relationship, but not living with their partner. Women who were not living with their partner had been in a relationship with their partner for an average of 5.64 years (SD = 5.10 years) and reported seeing their partner for an average of 5.24 days a week (SD = 2.33 days). Twenty-three percent of the women reported that they were primigravidas, with the remainder of the sample reporting an average gravidity of 3.01 (range 1�C12, mode = 1).