Urinary 8-hydroxy-2′-deoxyguanosine levels and small-for-gestational age infants: A prospective cohort study from the Japan Environment and Children's Study

Abstract

Objectives To evaluate the association between the urinary 8-hydroxy-2′-deoxyguanosine (U8-OHdG) levels and the incidence of small-for-gestational age (SGA) infants and to assess the utility of U8-OHdG as a biomarker to predict the incidence of SGA infants. Design Prospective cohort study. Setting The Japan Environment and Children's Study. Participants Data of participants enrolled in the Japan Environment and Children's Study, a nationwide birth cohort study, between 2011 and 2014 were analysed; 104 062 fetal records were analysed. Data of women with singleton pregnancies ≥22 weeks of gestation were analysed. Primary and secondary outcome measures U8-OHdG levels were assessed using liquid chromatography-tandem mass spectrometry. Participants were categorised into the following three groups according to the quartile of the distribution of U8-OHdG: low U8-OHdG (<1.95 ng/mgCre), moderate U8-OHdG (the combined second and third quartiles; 1.95-2.95 ng/mgCre) and high U8-OHdG (>2.95 ng/mgCre) groups. Additionally, participants in the 90th percentile for U8-OHdG levels were analysed. Odds ratios (ORs) for SGA infants (