Association between maternal passive smoking and increased risk of delivering small-for-gestational-age infants at full-term using plasma cotinine levels from The Hokkaido Study: a prospective birth cohort.

Objectives: To investigate the association between plasma cotinine level measured at the 8th gestational month and the delivery of small-for-gestational-age (SGA) infants, using a highly sensitive ELISA method.

Design: Prospective birth cohort study from The Hokkaido Study on Environment and Children's Health.

Setting: Hokkaido, Japan.

Modification of adverse health effects of maternal active and passive smoking by genetic susceptibility: Dose-dependent association of plasma cotinine with infant birth size among Japanese women-The Hokkaido Study.

Objectives: We aimed to assess the individual dose-response effects of eight maternal polymorphisms encoding polycyclic aromatic hydrocarbon-metabolizing and DNA-repair genes on prenatal cotinine levels according to infant birth size.

Methods: In total, 3263 Japanese pregnant women were assigned to five groups based on plasma cotinine levels during the 8th month of pregnancy, as measured using ELISA (cut-offs: 0.21, 0.

Association of prenatal passive smoking and metabolic gene polymorphisms with child growth from birth to 3years of age in the Hokkaido Birth Cohort Study on Environment and Children's Health.

Although the effects of prenatal passive smoking on birth weight have been reported, the effects of metabolic gene polymorphisms on passive smoking have not been studied. Therefore, we investigated the effects of maternal passive smoking and metabolic gene polymorphisms on child growth up to 3years of age using cotinine as a biomarker. We included 1356 Japanese participants in a prospective cohort between 2003 and 2007 (cotinine levels at the third trimester≤0.

Combined effects of AHR, CYP1A1, and XRCC1 genotypes and prenatal maternal smoking on infant birth size: Biomarker assessment in the Hokkaido Study.

Objectives: We investigated the individual and combined effects of maternal polymorphisms encoding the aromatic hydrocarbon receptor (AHR; rs2066853), cytochrome P450 (CYP) 1A1 (rs1048963), and the X-ray-complementing gene 1 (XRCC1; rs1799782) and prenatal smoking in relation to infant birth size.

Methods: Totally, 3263 participants (1998 non-smokers and 1265 smokers) were included in the study between 2003 and 2007. Two groups of mothers were distinguished by plasma cotinine levels by ELISA measured during the third trimester (cut-off=11.

Effects of maternal 5,10-methylenetetrahydrofolate reductase C677T and A1298C Polymorphisms and tobacco smoking on infant birth weight in a Japanese population.

Background: Intracellular folate hemostasis depends on the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. Because 5,10-MTHFR 677TT homozygosity and tobacco smoking are associated with low folate status, we tested the hypothesis that smoking in mothers with 5,10-MTHFR C677T or A1298C polymorphisms would be independently associated with lower birth weight among their offspring.

Methods: We assessed 1784 native Japanese mother-child pairs drawn from the ongoing birth cohort of The Hokkaido Study on Environment and Children's Health.