Smoking During Pregnancy Increases Risks of Various Obstetric Complications: A Case-Cohort Study of the Japan Perinatal Registry Network Database

Abstract

BackgroundThe adverse effects of maternal smoking on the health of pregnant women have been examined mostly on a disease-by-disease basis. The aims of this study were to evaluate simultaneously the effects of smoking during pregnancy on various obstetric complications, using data from a large medical database, and to investigate the expediency of using a case-cohort design for such an analysis.MethodsA case-cohort study was conducted within the Japan Perinatal Registry Network database. Perinatal information on infant deliveries was entered into the database at 125 medical centers in Japan. The base population of the study was 180 855 pregnant women registered in the database from 2001 through 2005. The outcome measures were the incidences of 11 different obstetric complications. Logistic regression models were used to estimate age-adjusted risk ratios (aRRs) and relative excess incidence proportions (REIs).ResultsThe overall prevalence of smoking during pregnancy was 5.8% in the base cohort, and the prevalence was higher among younger women. A comparison of the cases and control cohort showed that smokers during pregnancy had statistically significant higher risks for preterm rupture of the membrane (aRR: 1.67, 95% confidence interval [CI]: 1.43–1.96; REI: 40.2%, 95% CI: 29.9%–49.1%), chorioamnionitis (1.65, 1.36–2.00; 39.4%, 26.4%–50.0%), incompetent cervix (1.63, 1.35–1.96; 38.5%, 25.8%–49.1%), threatened premature delivery (1.38, 1.17–1.64; 27.7%, 14.5%–38.9%), placental abruption (1.37, 1.10–1.72; 27.1%, 8.8%–41.7%), and pregnancy-induced hypertension (1.20, 1.01–1.41; 16.4%, 1.2%–29.3%).ConclusionsMaternal smoking was associated with a number of obstetric complications. This highlights the importance of smoking cessation during pregnancy. In addition, case-cohort analysis proved useful in estimating RRs for multiple outcomes in a large database.

Outcome of Pregnancy and Effects on the Right Heart in Women With Repaired Tetralogy of Fallot

“…The incidence of PIH was 5%, which is similar to that in the Japanese general population (4%). 22 Because one of the patients with PIH had a BP fall from a bigeminal pulse, obstetric events such as PIH may cause fetomaternal morbidity in patients with repaired TOF to a greater extent than in the general population.…”

Common Respiratory Issues in Ambulatory Obstetrics

“…47 Figure 1 shows the relative excess incidence proportions of various obstetrical complications significantly associated with smoking during pregnancy. 48 Thus, decreasing the smoking rate in pregnancy may prevent a significant percentage of serious obstetrical complications.…”

Das Fetale Tabaksyndrom – Ein Statement der Österreichischen Gesellschaften für Allgemein- und Familienmedizin (ÖGAM), Gynäkologie und Geburtshilfe (ÖGGG), Hygiene, Mikrobiologie und Präventivmedizin (ÖGHMP), Kinder- und Jugendheilkunde (ÖGKJ) sowie Pneumologie (ÖGP)

“…In einer rezenten Studie bei 180.855 Schwangeren in Japan fand sich eine Prävalenz von insgesamt 5,8 %, die Prävalenz bei den unter 19-Jährigen lag jedoch mit 15,7 % deutlich höher [6]. Prospektive Daten einer rezenten Geburtskohortenstudie mit 7.121 Kindern in Großbritannien zeigten eine vergleichbare Gesamtprävalenz von 9,5 % [7] 25.000 Schwangerschaften für Spontanaborte keinen signifi kanten Unterschied zwischen rauchenden und nicht-rauchenden Frauen [23].…”