Smoking-behavior during pregnancy and the reliability of an interview were prospectively investigated. The tobacco-exposure was assessed a) by an intake interview b) by a smoking diary and c) by maternal thiocyanate and carboxy-hemoglobin concentrations. Of the 115 nulliparous women, 66 smoked (57.4%). Seventeen women (25.8%) quit and 39 women (59.1%) reduced smoking. Directly after intake, in the first week of the diary, significantly more cigarettes were smoked than stated during the intake interview. According to the diaries, the number of cigarettes increased during the first half of pregnancy. In the 24th week significantly more cigarettes were smoked than in the first week after intake. Also a significant increase of thiocyanate between the measurements at intake and in the 24th of amenorrhea was found. The maternal carboxy-hemoglobin levels did not significantly change during pregnancy. Investigators should be aware of changes in smoking behavior during pregnancy and the potential bias of self reported smoking behavior at the beginning of pregnancy. The tobacco-exposure should be assessed (anamnestic or biochemical) several times during pregnancy, anyway it should include the second half of pregnancy.
OBJECTIVE: To examine how a healthy lifestyle is related to life expectancy that is free from major chronic diseases.DESIGN: Prospective cohort study.SETTING AND PARTICIPANTS: The Nurses' Health Study (1980-2014; n=73 196) and the Health Professionals Follow-Up Study (1986-2014; n=38 366).MAIN EXPOSURES: Five low risk lifestyle factors: never smoking, body mass index 18.5-24.9, moderate to vigorous physical activity (≥30 minutes/day), moderate alcohol intake (women: 5-15 g/day; men 5-30 g/day), and a higher diet quality score (upper 40%).MAIN OUTCOME: Life expectancy free of diabetes, cardiovascular diseases, and cancer.RESULTS: The life expectancy free of diabetes, cardiovascular diseases, and cancer at age 50 was 23.7 years (95% confidence interval 22.6 to 24.7) for women who adopted no low risk lifestyle factors, in contrast to 34.4 years (33.1 to 35.5) for women who adopted four or five low risk factors. At age 50, the life expectancy free of any of these chronic diseases was 23.5 (22.3 to 24.7) years among men who adopted no low risk lifestyle factors and 31.1 (29.5 to 32.5) years in men who adopted four or five low risk lifestyle factors. For current male smokers who smoked heavily (≥15 cigarettes/day) or obese men and women (body mass index ≥30), their disease-free life expectancies accounted for the lowest proportion (≤75%) of total life expectancy at age 50.CONCLUSION: Adherence to a healthy lifestyle at mid-life is associated with a longer life expectancy free of major chronic diseases.
