Does Breastfeeding Behavior Run in Families? Evidence From Twins, Their Sisters and Their Mothers in the Netherlands

Abstract

The aim of the present article was to study the prevalence and the heritability of the initiation of breastfeeding in the Netherlands. The study was carried out in 5,581 participants from the Netherlands Twin Register, and included female twins, their sisters and mothers. All of the participants were born between 1911 and 1991. Breastfeeding was self-reported by the participants, and its prevalence was estimated conditional on birth cohort (born before 1955, 1955-1964, 1965-1974, 1975, or later). To estimate the heritability, we conducted extended twin-family modeling using the SEM package OpenMx in R. Mothers of twins had lower prevalence to initiate breastfeeding and the prevalence of initiation of breastfeeding increased with birth cohort: among mothers of twins 66% in the oldest (pre-1955) to 74% in the youngest (post-1974) and among mothers, who were twins themselves or sisters of twins, 79% in the oldest (pre-1955) to 85% in the youngest (post-1974). When accounting for prevalence differences between mothers of twins and other women, heritability of initiation of breastfeeding was 70%. However, the familial resemblance for sister and mother-daughter pairs was clearly lower than for DZ twin pairs, but as the number of non-twin sisters was relatively low, this observation did not lead to a significant contribution of a special shared twin environment.

Infant feeding practices and childhood acute leukemia: Findings from the Childhood Cancer & Leukemia International Consortium

“…36,37 Finally, twin studies provide evidence that breastfeeding practices are partly heritable. 40,41 Therefore, differences in breastfeeding practices may reflect differences in genetics, which could contribute to their associations with ALL and AML.…”

“…Although the hypotheses put forward to explain the reduced risk of leukemia among breastfed children were proposed in the context of B‐ALL, 29 breast milk constituents also interact with myeloid cells, supporting a potential mechanistic role for breastfeeding in the prevention of AML 36,37 . Finally, twin studies provide evidence that breastfeeding practices are partly heritable 40,41 . Therefore, differences in breastfeeding practices may reflect differences in genetics, which could contribute to their associations with ALL and AML.…”

DNA Methylation Signatures of Breastfeeding in Buccal Cells Collected in Mid-Childhood

“…It should be noted that breastfeeding and lactation itself are heritable traits. In previous twin studies, the heritability of initiation of breastfeeding ranged from 49% [128] to 70% [129]. DNA-methylation profiles may be influenced by several early life factors.…”

No evidence of association of oxytocin polymorphisms with breastfeeding in 2 independent samples

“…Three different twin and family studies from diverse cultural backgrounds (Spain, Australia and The Netherlands) have found significant heritability estimates (44–70%) for initiation and duration of breastfeeding behaviour (Colodro-Conde, Sanchez-Romera, & Ordonana, 2013; Colodro-Conde et al, 2015; Merjonen, Dolan, Bartels, & Boomsma, 2015). This means that approximately half of the inter-individual variability observed in the behaviour of breastfeeding is due to differences in genetic makeup, and the other half is due to differences in environmental related experiences.…”