Sex Differences in Fetal Growth Responses to Maternal Height and Weight

• Type of Material: Article
• Authors: Michelle Lampl, Emory University; Francesca Gotsch, Eunice Kennedy Shriver National Institute of Child Health and Development; Juan Pedro Kusanovic, Eunice Kennedy Shriver National Institute of Child Health and Development; Ricardo Gomez, Pontificia Universidad Catolica de Chil; Jyh Kae Kae Nien, Pontificia Universidad Catolica de Chil; Edward A. Frongillo, University of South Carolina; Roberto Romero, Eunice Kennedy Shriver National Institute of Child Health and Development
• Language: English
• Date: 2010-07-01
• Publisher: Wiley: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2009 Wiley-Liss, Inc.
• Final Published Version (URL): http://dx.doi.org/10.1002/ajhb.21014
• Title of Journal or Parent Work: American Journal of Human Biology
• ISSN: 1042-0533
• Volume: 22
• Issue: 4
• Start Page: 431
• End Page: 443
• Grant/Funding Information: This research was supported (in part) by the Perinatology Research Branch, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, DHHS.
• Keywords: RISK-FACTORS; Anthropology; Life Sciences & Biomedicine; Science & Technology; PREGNANCY; GESTATIONAL-AGE; Life Sciences & Biomedicine - Other Topics; PROSPECTIVE COHORT; PLACENTAL VOLUME; MALE PREDOMINANCE; GAIN; GENDER; LOW-BIRTH-WEIGHT; INTRAUTERINE GROWTH; Biology
• Research Categories: Health Sciences, Obstetrics and Gynecology

Abstract

Sex differences in fetal growth have been reported, but how this happens remains to be described. It is unknown if fetal growth rates, a reflection of genetic and environmental factors, express sexually dimorphic sensitivity to the mother herself. This analysis investigated homogeneity of male and female growth responses to maternal height and weight. The study sample included 3,495 uncomplicated singleton pregnancies followed longitudinally. Analytic models regressed fetal and neonatal weight on tertiles of maternal height and weight, and modification by sex was investigated (n=1,814 males, n=1,681 females) with birth gestational age, maternal parity, and smoking as covariates. Sex modified the effects of maternal height and weight on fetal growth rates and birth weight. Among boys, tallest maternal height influenced fetal weight growth before 18 gestational weeks of age (P = 0.006), and prepregnancy maternal weight and body mass index subsequently had influence (P <0.001); this was not found among girls. Additionally, interaction terms between sex, maternal height, and maternal weight identified that males were more sensitive to maternal weight among shorter mothers (P = 0.003) and more responsive to maternal height among lighter mothers (P - 0.03), compared to females. Likewise, neonatal birth weight dimorphism varied by maternal phenotype. A male advantage of 60 g occurred among neonates of the shortest and lightest mothers (P = 0.08), compared to 150 and 191 g among short and heavy mothers, and tall and light-weight mothers, respectively (P = 0.01). Sex differences in response to maternal size are under-appreciated sources of variation in fetal growth studies and may reflect differential growth strategies. Am. J. Hum. Biol. 22:431-443, 2010.