Population Attributable Fractions of Modifiable Risk Factors for Nonsyndromic Orofacial Clefts: A Prospective Cohort Study From the Japan Environment and Children's Study.

Yukihiro Sato,Chihiro Miyashita,Sachiko Itoh,Keiko Yamazaki,Yu Ait Bamai,Sumitaka Kobayashi,Reiko Kishi,Yusuke Tanahashi,Hiroshi Azuma,Kazuo Sengoku,Machiko Minatoya,Toshinobu Miyamoto,Atsuko Araki,Eiji Yoshioka,Yoshiya Ito,Yasuaki Saijo

doi:10.2188/jea.je20190347

Abstract

BackgroundPopulation impact of modifiable risk factors on orofacial clefts is still unknown. This study aimed to estimate population attributable fractions (PAFs) of modifiable risk factors for nonsyndromic cleft lip with or without cleft palate (CL±P) and cleft palate only (CP) in Japan.MethodsWe conducted a prospective cohort study using data from the Japan Environment and Children’s Study, which recruited pregnant women from 2011 to 2014. We estimated the PAFs of maternal alcohol consumption, psychological distress, maternal active and passive smoking, abnormal body mass index (BMI) (<18.5 and ≥25 kg/m2), and non-use of a folic acid supplement during pregnancy for nonsyndromic CL±P and CP in babies.ResultsA total of 94,174 pairs of pregnant women and their single babies were included. Among them, there were 146 nonsyndromic CL±P cases and 41 nonsyndromic CP cases. The combined adjusted PAF for CL±P of the modifiable risk factors excluding maternal alcohol consumption was 34.3%. Only maternal alcohol consumption was not associated with CL±P risk. The adjusted PAFs for CL±P of psychological distress, maternal active and passive smoking, abnormal BMI, and non-use of a folic acid supplement were 1.4% (95% confidence interval [CI], −10.7 to 15.1%), 9.9% (95% CI, −7.0 to 26.9%), 10.8% (95% CI, −9.9 to 30.3%), 2.4% (95% CI, −7.5 to 14.0%), and 15.1% (95% CI, −17.8 to 41.0%), respectively. We could not obtain PAFs for CP due to the small sample size.ConclusionsWe reported the population impact of the modifiable risk factors on CL±P, but not CP. This study might be useful in planning the primary prevention of CL±P.

Highlights

Orofacial clefts are a common congenital anomaly, with approximately 1 case per 700 live births.[1,2] Especially Chinese and Japanese has a high incidence rate of orofacial clefts compared with other ethnicities.[1]
The current study showed a relatively similar odds ratios (ORs) of maternal active smoking for cleft palate (CL±P) (OR of former smoker who quit before pregnancy, 1.27; 95% confidence intervals (CIs), 0.85–1.90 and OR of former smoker who smoke during pregnancy and quit afterwards, 1.28; 95% CI, 0.77–2.12), excluding current smoking
Our study measured nonspecific psychological distress using the K6 and might support the associations of cleft lip (CL)±P. This prospective cohort study shows the association of the modifiable risk factors with CL±P and the population impact in Japan

Summary

Introduction

Orofacial clefts are a common congenital anomaly, with approximately 1 case per 700 live births.[1,2] Especially Chinese and Japanese has a high incidence rate of orofacial clefts compared with other ethnicities.[1]. Orofacial clefts are classified into two etiologically distinct groups, which result from inadequate formations during embryogenesis development: cleft lip with or without cleft palate (CL±P) and cleft palate only (CP). This anomaly can be part of a syndrome or malformations; there are nonsyndromic (without other congenital anomalies and any syndrome) and syndromic cases. Population impact of modifiable risk factors on orofacial clefts is still unknown. This study aimed to estimate population attributable fractions (PAFs) of modifiable risk factors for nonsyndromic cleft lip with or without cleft palate (CL±P) and cleft palate only (CP) in Japan

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