Table 1 Characteristics of included studies of maternal BMI and ASD risk in the meta-analysis.

From: Maternal Body Mass Index and Risk of Autism Spectrum Disorders in Offspring: A Meta-analysis

Author

Location

Study

Design

Age (y)

Time and ascertainment of BMI

Ascertainment of ASDs

ASD cases/Total participants

Confounding

Lyall 201117

USA

The Nurses’Health Study II (NHS II)

Prospective cohort

NA

Pre-pregnancy Self-reported

Parental report

221/8, 498

Maternal age at baseline, race, income, body shape at age 20, cycle length, and age at menarche

Krakowiak 201216

USA

Childhood Autism Risks from Genetics and the Environment Study (CHARGE)

Population-based case-control

2–5

Pre-pregnancy Extracted from medical record or self-reported

Identified through regional centers, providers/clinics, self referrals, and general public outreach. Validated with ADI-R and ADOS by trained clinicians

517/1, 004

Maternal age at delivery, race/ethnicity, education level, delivery payer, calendar time; child’s age at enrollment and gender, and catchment area

Surén 201418

Norway

Norwegian Mother and Child Cohort Study

Prospective cohort

4–13.1

Pre-pregnancy Self-reported

Identified by questionnaire screening of mothers, professional and parental referrals of ASD suspection, linkage to the Norwegian Patient Register. Validated with ADI-R and ADOS

419/92,909

Parental education levels, child’s year of birth, and maternal parity

Moss 20149

USA

The Early Childhood Longitudinal Study–Birth Cohort (ECLS-B)

Prospective cohort

4–5

Pre-pregnancy Self-reported

Parental report

100/4,800

Maternal age; child sex, birth weight, rates of height growth and weight gain; paternal BMI

Reynolds 201414

USA

A prospective cohort study at a level-III neonatal intensive care unit

Prospective cohort

2

Pre-pregnancy Extracted from medical record

Identified by M-CHAT

14/62

Gestational age at birth, markers of sociodemographics

Gardner 20158

Sweden

Stockholm Youth Cohort (SYC)

Prospective cohort

NA

At first antenatal visit Objectively measured

Ascertained by using ICD-9, ICD-10, and DSM-IV codes

6,420/333,057

Child’s sex, birth year, parity; parental age at the time of birth, maternal country of birth, paternal BMI, SES factors and parental history of psychiatric treatment

Xiang 20157

USA

Kaiser Permanente Southern California (KPSC) Study

Retrospective cohort

1.5–2

Pre-pregnancy Extracted from medical record

Identified by M-CHAT, ascerntained by pediatric developmental specialist evaluations

712/68,837

Birth year

  1. *ADI-R: Autism Diagnostic Interview Revised ADOS: Autism Diagnostic Observation Schedule M-CHAT: The Modified Checklist for Autism in Toddlers.