Does parental body mass index status modify the associations among birth weight, early growth and childhood adiposity?

Birthweight associations with parental obesity: retrospective analysis of 1,778 singleton term births following assisted reproductive treatment

Objective

To determine the association of combined parental preconception overweight and obesity on infant birthweight.

Design

Retrospective study of fresh in vitro fertilization or intracytoplasmic sperm injection cycles (2009–2017).

Setting

Repromed, South Australia, assisted reproductive technology clinic.

Patients

Couples undergoing in vitro fertilization/intracytoplasmic sperm injection insemination with their own gametes and transfer of a fresh single blastocyst (N = 1,778).

Intervention(s)

None.

Main Outcome Measures

Parental body mass index (BMI) was recorded prior to cycle initiation. Infant birthweight was recorded at delivery. The impact of parental obesity and their interaction on first singleton term (≥37 weeks’ gestation) birthweight was assessed using linear regressions assessing nonlinearity and a pairwise linear interactions.

Results

In the base model where parental BMI is assumed linear, there was strong evidence for higher birthweight with increasing maternal BMI (11.2 g per maternal kg/m²; 95% confidence interval, 7.2, 15.1) but not paternal BMI. The inclusion of a pairwise linear interaction indicated that paternal BMI attenuates the positive association between maternal BMI and infant birthweight (interaction −0.88; 95% confidence interval, −1.49, −0.27). The inclusion of nonlinear maternal BMI terms did not change the conclusions.

Conclusions

Increases in the mean infant birthweight associated with maternal obesity are attenuated when the father is obese. While maternal BMI contributed more to the mean infant birthweight than paternal BMI, a couple-centered approach to preconception health advice is recommended, given the documented relationships between parental obesity and childhood weight beyond infancy. Further studies in both assisted reproductive technology and general population cohorts assessing the parental BMI interaction on infant birthweight are warranted.

[Influence of pre-pregnancy parental body mass index, maternal weight gain during pregnancy, and their interaction on neonatal birth weight]

OBJECTIVE

To investigate the influence of pre-pregnancy parental body mass index (BMI), maternal weight gain during pregnancy, and their interaction on neonatal birth weight.

METHODS

A total of 1 127 pregnant women who underwent regular prenatal examinations and full-term singleton delivery in the First Hospital of Xi'an Jiaotong University from January 2017 to October 2018 were enrolled. The data on their pre-pregnancy BMI, maternal weight gain during pregnancy, pre-pregnancy BMI of the husband, and neonatal birth weight were collected. The interaction between pre-pregnancy parental BMI and maternal weight gain during pregnancy was analyzed, and their correlation with neonatal birth weight was analyzed.

RESULTS

Among the 1 127 full-term neonates, the detection rates of low birth weight neonates and macrosomia were 2.22% (25/1 127) and 3.82% (43/1 127) respectively. There were significant differences in pre-pregnancy parental BMI and maternal weight gain during pregnancy among the low birth weight, normal birth weight, and macrosomia groups (P<0.05). Neonatal birth weight was positively correlated with pre-pregnancy parental BMI and maternal weight gain during pregnancy (r=0.097-0.322, P<0.05). Low maternal weight before pregnancy increased the risk of low birth weight (RR=4.17, 95%CI: 1.86-9.38), and maternal overweight/obesity before pregnancy (RR=3.59, 95%CI: 1.93-6.67) and excessive weight gain during pregnancy (RR=3.21, 95%CI: 1.39-7.37) increased the risk of macrosomia. No interaction between pre-pregnancy maternal BMI and maternal weight gain during pregnancy was observed.

CONCLUSIONS

Pre-pregnancy parental BMI and maternal weight gain during pregnancy are related to neonatal birth weight, and there is no interaction between pre-pregnancy maternal BMI and maternal weight gain during pregnancy.

Cumulative incidence of youth obesity is associated with low cardiorespiratory fitness levels and with maternal overweight

Abstract This longitudinal study evaluated the association between the incidence of youth overweight/obesity (Ow/Ob) and low levels of cardiorespiratory fitness (CRF) over 4 years and youths' and their parents' demographic and nutritional characteristics. The randomized sample comprised 398 youth, aged 7-17 years at baseline, from a city in southern Brazil. Subjects were classified as being Ow/Ob according to international body mass index (BMI) parameters. Parental weight and height were determined by direct questioning. Youth CRF was measured by a 9-minute walk-and-run test. The cumulative incidences of Ow/Ob and of low CRF levels were 25.1% and 20.5%, respectively. Relative to other youth, youth who were classified as "unhealthy" at baseline (with respect to CRF) and by the fourth year were more likely to be classified as Ow/Ob (relative risks: 1.12 and 1.10, respectively). Youth whose mothers were categorized as Ow/Ob were at higher risk of being classified as Ow/Ob than youth whose mothers had normal BMIs (relative risks: 1.19 at baseline and 1.20 in the fourth year). The incidence of Ow/Ob among the former youth was associated with low CRF levels and with maternal Ob.

Parental Body Mass Index, Gestational Weight Gain, and Risk of Macrosomia: a Population-Based Case-Control Study in China

BACKGROUND

The prevalence of macrosomia has risen markedly worldwide, including in China, during the past two decades. Few epidemiological studies, however, have investigated the risk factors for macrosomia in China. This study was designed to investigate the associations between parental anthropometric characteristics, gestational weight gain (GWG), and risk of macrosomia in China.

METHODS

This population-based, case-control study in Wuhan, China, included a total of 6341 subjects (870 cases and 5471 controls). Multivariable logistic regression was conducted to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

Mothers or fathers who were overweight or obese before pregnancy had an elevated risk of giving birth to a macrosomic infant compared with their normal weight counterparts. Women with GWG above the Institute of Medicine (IOM) recommendation had an adjusted OR of 6.09 [95% CI 5.04, 7.35] for delivering a macrosomic infant compared with women who had GWG within the IOM recommendation. When stratified by maternal pre-pregnancy body mass index (BMI), women who were underweight or normal weight before pregnancy were observed to have a higher risk of macrosomia birth associated with greater GWG.

CONCLUSIONS

Parental pre-pregnancy overweight/obesity and excessive GWG during pregnancy were highly associated with macrosomia. The association with GWG was most pronounced in mothers who had a normal or underweight pre-pregnancy BMI. Weight control efforts before pregnancy for mothers and fathers as well as control of maternal gain during pregnancy may reduce the risk of macrosomia.