A principal components approach to parent-to-newborn body composition associations in South India

Paternal obesity modifies the effect of an antenatal lifestyle intervention in women who are overweight or obese on newborn anthropometry

The contribution of paternal obesity to pregnancy outcomes has been little described. Our aims were to determine whether the effect of an antenatal maternal dietary and lifestyle intervention among women who are overweight or obese on newborn adiposity, was modified by paternal obesity. We conducted a secondary analysis of a multicenter randomised trial. Pregnant women with BMI ≥25 kg/m² received either Lifestyle Advice or Standard Care. Paternal anthropometric measures included height, weight, BMI; waist, hip, calf and mid-upper arm circumferences; biceps and calf skinfold thickness measurements (SFTM); and percentage body fat. Newborn anthropometric outcomes included length; weight; head, arm, abdominal, and chest circumferences; biceps, triceps, subscapular, suprailiac, thigh, and lateral abdominal wall SFTM; and percentage body fat. The effect of an antenatal maternal dietary and lifestyle intervention among women who were overweight or obese on neonatal anthropometric measures, was significantly modified by paternal BMI ≥35.0 kg/m², with a significantly smaller infant triceps, suprailiac, and thigh SFTM, and percent fat mass, compared with that observed in offspring of lean fathers. Further research is required to determine whether our observed associations are causal, and whether paternal weight loss prior to conception is a potential strategy to reduce the intergenerational effects of obesity.

Body composition of term healthy Indian newborns

BACKGROUND/OBJECTIVES

Previous anthropometry-based studies have suggested that in Indian newborns fat mass is conserved at the expense of lean tissue. This study was undertaken to assess the body composition of Indian newborns and to evaluate its relation with parents' anthropometry, birth weight and early postnatal weight gain.

SUBJECTS/METHODS

Body composition of healthy term singleton newborns was assessed by the deuterium dilution method in the second week of life. Anthropometry was carried out at birth and on the day of study.

RESULTS

Data from 127 babies were analyzed. Birth weight was 2969±383 g. Body composition was assessed at a mean age of 12.7±3.1 days. Fat and fat-free mass were 354±246 and 2764±402 g, respectively, and fat mass percentage (FM%) was 11.3±7.3%. Birth weight and fat-free mass were higher among boys, but no gender difference was noted in FM%. Birth weight was positively correlated with fat as well as fat-free mass but not FM%. FM% showed positive correlation with gain in weight from birth to the day of assessment.

CONCLUSIONS

This is the first study from India to report body composition in newborns using deuterium dilution. FM% was comparable to that reported for Western populations for babies of similar age. Our results suggest that the percentage of fat and fat-free mass is relatively constant over the range of birth weights included in this study, and greater weight gain during early postnatal period results in greater increase in FM%.

Relationships of maternal and paternal anthropometry with neonatal body size, proportions and adiposity in an Australian cohort

The patterns of association between maternal or paternal and neonatal phenotype may offer insight into how neonatal characteristics are shaped by evolutionary processes, such as conflicting parental interests in fetal investment and obstetric constraints. Paternal interests are theoretically served by maximizing fetal growth, and maternal interests by managing investment in current and future offspring, but whether paternal and maternal influences act on different components of overall size is unknown. We tested whether parents' prepregnancy height and body mass index (BMI) were related to neonatal anthropometry (birthweight, head circumference, absolute and proportional limb segment and trunk lengths, subcutaneous fat) among 1,041 Australian neonates using stepwise linear regression. Maternal and paternal height and maternal BMI were associated with birthweight. Paternal height related to offspring forearm and lower leg lengths, maternal height and BMI to neonatal head circumference, and maternal BMI to offspring adiposity. Principal components analysis identified three components of variability reflecting neonatal “head and trunk skeletal size,” “adiposity,” and “limb lengths.” Regression analyses of the component scores supported the associations of head and trunk size or adiposity with maternal anthropometry, and limb lengths with paternal anthropometry. Our results suggest that while neonatal fatness reflects environmental conditions (maternal physiology), head circumference and limb and trunk lengths show differing associations with parental anthropometry. These patterns may reflect genetics, parental imprinting and environmental influences in a manner consistent with parental conflicts of interest. Paternal height may relate to neonatal limb length as a means of increasing fetal growth without exacerbating the risk of obstetric complications. Am J Phys Anthropol 156:625–636, 2015.

Ethnic differences in neonatal body composition in a multi-ethnic population and the impact of parental factors: a population-based cohort study

BACKGROUND

Neonates from low and middle income countries (LAMIC) tend to have lower birth weight compared with Western European (WE) neonates. Parental height, BMI and maternal parity, age and educational level often differ according to ethnic background, and are associated with offspring birth weight. Less is known about how these factors affect ethnic differences in neonatal body composition.

OBJECTIVES

To explore differences in neonatal body composition in a multi-ethnic population, and the impact of key parental factors on these differences.

METHODS

A population-based cohort study of pregnant mothers, fathers and their offspring, living in Oslo, Norway. Gender- and gestational-specific z-scores were calculated for several anthropometric measurements, with the neonates of WE ethnic origin as reference. Mean z-scores for neonates with LAMIC origin, and their parents, are presented as outcome variables.

RESULTS

537 singleton, term neonates and their parents were included. All anthropometric measurements were smaller in neonates with LAMIC origin. Abdominal circumference and ponderal index differed the most from WE (mean z-score: -0.57 (95% CI:-0.69 to -0.44) and -0.54 (-0.66 to -0.44), and remained so after adjusting for parental size. Head circumference and skin folds differed less, and length the least (-0.21 (-0.35 to -0.07)). These measures became comparable to WEs when adjusted for parental factors.

CONCLUSIONS

LAMIC origin neonates were relatively "thin-fat", as indicated by reduced AC and ponderal index and relatively preserved length and skin folds, compared with neonates with WE origin. This phenotype may predispose to type 2 diabetes.

Sex differences in fetal growth responses to maternal height and weight

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 < or = 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.