Paternal Smoking and Pregnancy Loss: A Prospective Study Using a Biomarker of Pregnancy

Abstract

Results of studies on paternal smoking and spontaneous abortions have been inconsistent. The authors examined the effect of paternal smoking on the risk of pregnancy loss in a prospective cohort of 526 newly married, nonsmoking, female textile workers in China between 1996 and 1998. Upon stopping contraception, subjects provided daily urine specimens and records of vaginal bleeding for up to 1 year or until clinical pregnancy. Daily urinary human chorionic gonadotropin was assayed to detect conception and early pregnancy losses, and pregnancies were followed to detect clinical spontaneous abortions. Subjects were grouped by the number of cigarettes that husbands reported smoking daily: nonsmokers (group 1, n = 216), fewer than 20 cigarettes (group 2, n = 239), and 20 or more cigarettes (group 3, n = 71). Compared with that for group 1, the adjusted odds ratio of early pregnancy loss of any conception for group 2 was 1.04 (95% confidence interval (CI): 0.67, 1.63) and for group 3 was 1.81 (95% CI: 1.00, 3.29). The adjusted hazard ratio of conception for group 2 was 0.90 (95% CI: 0.70, 1.18) and for group 3 was 0.96 (95% CI: 0.66, 1.39), while the adjusted hazard ratio of clinical pregnancy for group 2 was 0.93 (95% CI: 0.72, 1.20) and for group 3 was 0.78 (95% CI: 0.55, 1.12). The authors conclude that heavy paternal smoking increased the risk of early pregnancy loss through maternal and/or paternal exposure.

Lifestyle Risk Factors Associated with Threatened Miscarriage: A Case-Control Study

“…Our finding of the increased risk associated with second-hand smoke exposure confirms previous studies that examined early pregnancy losses [16,17]. The mechanisms by which passive smoking increases the risk of miscarriage are believed to be similar to those of active smoking, mainly vasoconstriction [18], reduced placental blood flow due to nicotine [19], and maternal and fetal hypoxia due to carboxyhemoglobin formation [20][21][22].…”

Embryonic Resorption and Polycyclic Aromatic Hydrocarbons: Putative Immune-mediated Mechanisms

“…However, later epidemiological [Chatenoud et al 1998;George et al 2006] and metaanalyses [Augood et al 1998] provided additional data supporting the concept that maternal smoking increased the risk of spontaneous abortion. Moreover, exposure to second-hand smoke during pregnancy [Venners et al 2004] or childhood [Meeker et al 2007] has also been implicated in recurrent pregnancy loss. Finally, more recent data obtained from fertility clinics indicate a positive association between maternal exposure to tobacco smoke and the rate of spontaneous abortions [Lintsen et al 2005;Waylen et al 2009].…”

A prospective study of risk factors for first trimester miscarriage in Asian women with threatened miscarriage

“…Common risk factors include increased maternal age, high pre-pregnancy body mass index (BMI) and low serum progesterone levels. (11)(12)(13)(14) More recently, lifestyle factors such as caffeine intake, (15) exercise, (16) stress, (9,17) exposure to cigarette smoke, (18,19) and alcohol consumption (12,20,21) have also been implicated as risk factors. Some studies have documented the proportion of women who had experienced a threatened miscarriage who subsequently go on to experience a complete miscarriage.…”