Table 1 Characteristics of studies included in the systematic review and meta-analysis
From: Gestational weight gain and offspring’s cognitive skills: a systematic review and meta-analysis
| Study | Country | Studu design | Years of recruitment | n mothers | Mother’s age (i) | GWG classification | n offspring | Offspring’s age (i) | Measuring tools and cognitive domains | Adjustement variables |
|---|---|---|---|---|---|---|---|---|---|---|
| Gage et al. 2013 [38] | UK | Cohort | 1991–1992 | 8653 | 28.52 (4.75) | IOM 2009 |
5836 5191 7339 |
4 8 16 |
School entry assessment score. Wechsler Intelligence Scale for Children: - → Standarized IQ. School scores. |
Maternal’s variables: age, gestational age, parity, education, pregestational BMI, tobacco consumption and type of delivery. Offspring’s variables: sex, age at evaluation. |
| Hinkle et al. 2016 [13] | Norway and Sweden | Cohort | 1986–1988 | 344 | 29.1 (4.2) | IOM 2009 | 552 | 5.2 (0.2) |
Wechsler Preschoolers and Primary Scales of Intelligence (WPPSI-R), Full Scale: - → Verbal IQ. - → Performance IQ. - → Full scale IQ. |
Maternal’s variables: age, parity, education, IQ, socioeconomic status, civil status, pregestational BIM, prepregnancy diseases, smoking and alcohol use, nausea and vomiting during pregnancy. Offspring’s variables: sex, age at IQ assessment. Sensitive analysis limited to full-term birth. |
| Huang et al. 2014 [9] | USA | Cohort | 1959–1976 | 29,942 | 21.3 (8.4) | IOM 2009 |
8059 children with siblings. 22,513 children with no siblings. | 7.1 (0.8) |
Stanford–Binet intelligence scale and Graham–Ernhart Block Sort test. Wechsler Intelligence Scale for Children (WISC I): - → Verbal IQ - → Performance IQ - → Full scale IQ. | Maternal’s variables: age, race, education, civil status, socioeconomic status, parity, smoking in pregnancy and hospital. |
| Keim et al. 2012 [14] | USA | Cohort | 1959–1973 | 31,968 |
< 20: 20.3% 20–29: 64.4% 30–34: 11.3% > 35: 4% | IOM 2009 |
8704 children with siblings. 23,264 children with no siblings. |
4 4 7 7 |
Stanford–Binet intelligence scale Graham–Ernhart Block Sort test. Wechsler Intelligence Scale for Children. Wide Range Achievement Test (WRAT): - → Spelling - → Arithmetic |
Maternal’s variables: age, race, parity, socioeconomic status, and smoking. Offspring’s variables: sex and siblings. |
| Kominiarek et al. 2018 [39] | USA | Cohort | 2006–2009 | 948 | 27.95 (6.56) | IOM 2009 | 948 |
3 5 |
Differential Ability Scale-II. Wechsler Preschool and Primary Scale of Intelligence. |
Maternal’s variables: race–ethnicity and education. Offspring’s variables: sex. |
| Li et al. 2018 [15] | China | Cohort | 2002–2006 | 1744 | NR | IOM 2009 | 1307 | 8.78 (0.82) | Wechsler intelligence scale for children (WISC-IV) |
Maternal’s variables: parental age, gestational age, county, education, parents’ job, household wealth index, child school level, prenatal micronutrient supplementation, prepregnancy BMI. Offspring’s variables: age, sex, older siblings birth weight |
| Naeye et al. 1981 [12] | USA | Cohort | 1959–1966 | 2183 | NA | Own criteria (ii) | 2183 |
0.67 4 |
Bayley score. IQ. | Stratified by race, gestational age at birth, socioeconomic index (including education, work and family income). |
| Neggers et al. 2003 [16] | USA | Cohort | 1991–1993 | 355 | 21.6 (7.3) | IOM 1990 | 355 | 5.3 (0.3) |
Differential Ability Scales (DAS): - → IQ - → Verbal - → No verbal ability, Peabody gross motor scales (PPVT): - → Reflexes, - → Balance - → Locomotors reflexes. Peabody Picture Vocabulary Test (PPVT): - → Language skills. |
Maternal’s variables: age, gestational age, mother’s PPVT, tobacco use and maternal alcohol intake and zinc supplementation. Offspring’s variables: Offspring’s age, birth weight, home environment and childcare. |
| Pugh et al. 2015 [40] | USA | Cohort | 1983–1986 | 530 | NA | Own criteria (iii) | 530 | 10 |
Stanford-Binet Intelligence Scale: - → IQ. Wisconsin Card Sorting Test and Trail Making test: - → Cognitive flexibility. |
Maternal’s variables: race, parity, intelligence, socioeconomic status, education, job, civil status, depressive symptoms and preconception substance use. Offspring’s variables: sex and home environment. |
| Pugh et al. 2016 [35] | USA | Cohort | 1983–1986 | 574 | NA | Own criteria (iii) | 542 |
6 and 10 14 |
Wide Range Achievement Test-Revised (WRAT-R) - → Math. - → Reading. - → Spelling Wechsler Individual Achievement Test (WIAT): - → Math. - → Reading. - → Spelling |
Maternal’s variables: race, parity, job, intelligence, socioeconomic status, depression and pregestational BMI. Offspring’s variables: sex and home environment. |
| Tanda et al. 2013 [17] | USA | Cohort | 1978 | 3412 | 25.4 (5) | IOM 2009 | 3412 | 5.96 (0.64) |
Peabody individual achievement test (PIAT): - → Math. - → Reading. | Offspring’s variables: age and siblings. |
| Tavris et al. 1982 [36] | USA | Cohort | 1959–1966 | 2443 | NA | Own criteria (iv) | 1638 | 5 |
Raven Coloured Progressive” matrices test: - → Intelligence. | Confounding variables without adjusting for them: maternal age, race, parity, maternal education, weight/height ratio, time since the last gestation, parental education and socioeconomic status. |
| Widen et al. 2018 [37] | USA | Cohort | 1959–1966 | 2084 | 28.4 (5.9) | NR | 1825 | 9–11 |
Raven Coloured Progressive” matrices test: - → Intelligence. Peabody Picture Vocabulary Test (PPVT): - → Language skills. |
Maternal’s variables: race, age, parity, socioeconomic status, education, peabody IQ score and pregestational BMI. Offspring’s variables: birth weight and size. |
