title: Total and Trimester-Specific Gestational Weight Gain and Offspring Birth and Early Childhood Weight: A Prospective Cohort Study on Monozygotic Twin Mothers and Their Offspring.
abstract: Gestational weight gain (GWG) has in numerous studies been associated with offspring birth weight (BW) and childhood weight. However, these associations might be explained by genetic confounding as offspring inherit their mother's genetic potential to gain weight. Furthermore, little is known about whether particular periods of pregnancy could influence offspring body weight differently. We therefore aimed to explore total and trimester-specific effects of GWG in monozygotic (MZ) twin mother-pairs on their offspring's BW, weight at 1 year and body mass index (BMI) at 5 and 10 years. MZ twin mothers born 1962-1975 were identified in national Swedish registers, and data on exposure and outcome variables was collected from medical records. We analyzed associations within and between twin pairs. We had complete data on the mothers' GWG and offspring BW for 82 pairs. The results indicated that total, and possibly also second and third trimester GWG were associated with offspring BW within the twin pairs in the fully adjusted model (β = 0.08 z-score units, 95% CI: 0.001, 0.17; β = 1.32 z-score units, 95% CI: -0.29, 2.95; and β = 1.02 z-score units, 95% CI: -0.50, 2.54, respectively). Our findings, although statistically weak, suggested no associations between GWG and offspring weight or BMI during infancy or childhood. Our study suggests that total, and possibly also second and third trimester, GWG are associated with offspring BW when taking shared genetic and environmental factors within twin pairs into account. Larger family-based studies with long follow-up are needed to confirm our findings.
authors.affiliation: Department of Public Health Sciences,Child and Adolescent Public Health Epidemiology,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Elina
authors.initials: E
authors.lastname: Scheers Andersson
authors.affiliation: Department of Social Research,University of Helsinki,Helsinki,Finland.
authors.forename: Karri
authors.initials: K
authors.lastname: Silventoinen
authors.affiliation: Department of Public Health Sciences,Child and Adolescent Public Health Epidemiology,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Tynelius
authors.affiliation: Research Unit of Gynecology and Obstetrics,Institute of Clinical Research,University of Southern Denmark,Odense,Denmark.
authors.forename: Ellen A
authors.initials: EA
authors.lastname: Nohr
authors.affiliation: Novo Nordisk Foundation Centre for Basic Metabolic Research,Section on Metabolic Genetics,Faculty of Health and Medical Sciences,University of Copenhagen,Copenhagen,Denmark.
authors.forename: Thorkild I A
authors.initials: TI
authors.lastname: Sørensen
authors.affiliation: Department of Public Health Sciences,Child and Adolescent Public Health Epidemiology,Karolinska Institutet,Stockholm,Sweden.
authors.forename: Finn
authors.initials: F
authors.lastname: Rasmussen
mesh_terms: D000328:Adult; D001724:Birth Weight; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D005260:Female; D005865:Gestational Age; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011247:Pregnancy; D011264:Pregnancy Trimesters; D059285:Pregnancy, Twin; D013548:Sweden; D014430:Twins, Monozygotic; D015430:Weight Gain
keywords: birth weight; childhood body weight; genetics; gestational trimester; gestational weight gain; monozygotic twins