TY - JOUR

T1 - Association between birth weight and educational attainment

T2 - an individual-based pooled analysis of nine twin cohorts

AU - Jelenkovic, Aline

AU - Mikkonen, Janne

AU - Martikainen, Pekka

AU - Latvala, Antti

AU - Yokoyama, Yoshie

AU - Sund, Reijo

AU - Vuoksimaa, Eero

AU - Rebato, Esther

AU - Sung, Joohon

AU - Kim, Jina

AU - Lee, Jooyeon

AU - Lee, Sooji

AU - Stazi, Maria A.

AU - Fagnani, Corrado

AU - Brescianini, Sonia

AU - Derom, Catherine A.

AU - Vlietinck, Robert F.

AU - Loos, Ruth J. F.

AU - Krueger, Robert F.

AU - Mcgue, Matt

AU - Pahlen, Shandell

AU - Nelson, Tracy L.

AU - Whitfield, Keith E.

AU - Brandt, Ingunn

AU - Nilsen, Thomas S.

AU - Harris, Jennifer R.

AU - Cutler, Tessa L.

AU - Hopper, John L.

AU - Tarnoki, Adam D.

AU - Tarnoki, David L.

AU - Sorensen, Thorkild I. A.

AU - Kaprio, Jaakko

AU - Silventoinen, Karri

PY - 2018/9/1

Y1 - 2018/9/1

N2 - Background There is evidence that birth weight is positively associated with education, but it remains unclear whether this association is explained by familial environmental factors, genetic factors or the intrauterine environment. We analysed the association between birth weight and educational years within twin pairs, which controls for genetic factors and the environment shared between co-twins. Methods The data were derived from nine twin cohorts in eight countries including 6116 complete twin pairs. The association between birth weight and educational attainment was analysed both between individuals and within pairs using linear regression analyses. Results In between-individual analyses, birth weight was not associated with educational years. Within-pairs analyses revealed positive but modest associations for some sex, zygosity and birth year groups. The greatest association was found in dizygotic (DZ) men (0.65 educational years/kg birth weight, p=0.006); smaller effects of 0.3 educational years/kg birth weight were found within monozygotic (MZ) twins of both sexes and opposite-sex DZ twins. The magnitude of the associations differed by birth year in MZ women and opposite-sex DZ twins, showing a positive association in the 1915-1959 birth cohort but no association in the 1960-1984 birth cohort. Conclusion Although associations are weak and somewhat inconsistent, our results suggest that intrauterine environment may play a role when explaining the association between birth weight and educational attainment.

AB - Background There is evidence that birth weight is positively associated with education, but it remains unclear whether this association is explained by familial environmental factors, genetic factors or the intrauterine environment. We analysed the association between birth weight and educational years within twin pairs, which controls for genetic factors and the environment shared between co-twins. Methods The data were derived from nine twin cohorts in eight countries including 6116 complete twin pairs. The association between birth weight and educational attainment was analysed both between individuals and within pairs using linear regression analyses. Results In between-individual analyses, birth weight was not associated with educational years. Within-pairs analyses revealed positive but modest associations for some sex, zygosity and birth year groups. The greatest association was found in dizygotic (DZ) men (0.65 educational years/kg birth weight, p=0.006); smaller effects of 0.3 educational years/kg birth weight were found within monozygotic (MZ) twins of both sexes and opposite-sex DZ twins. The magnitude of the associations differed by birth year in MZ women and opposite-sex DZ twins, showing a positive association in the 1915-1959 birth cohort but no association in the 1960-1984 birth cohort. Conclusion Although associations are weak and somewhat inconsistent, our results suggest that intrauterine environment may play a role when explaining the association between birth weight and educational attainment.

KW - birth weight

KW - education

KW - twins/genetics

UR - http://www.scopus.com/inward/record.url?scp=85048016386&partnerID=8YFLogxK

U2 - 10.1136/jech-2017-210403

DO - 10.1136/jech-2017-210403

M3 - Journal article

C2 - 29848580

VL - 72

SP - 832

EP - 837

JO - Journal of Epidemiology & Community Health

JF - Journal of Epidemiology & Community Health

SN - 0143-005X

IS - 9

ER -