Body Composition During Pregnancy Differs by Obesity Class

Anthropometric Changes During Pregnancy and Their Association with Adequacy of Gestational Weight Gain

Background

Gestational weight gain (GWG) is an expected component of a healthy pregnancy. Gaining weight within the recommended range helps support the mother's health by providing energy reserves and nutrients to meet the increased metabolic demands during pregnancy. Too much or too little GWG has been associated with adverse health outcomes for the mother and child.

Objective

The objective of the study was to examine how changes in anthropometric indicators during pregnancy, including fat gain, vary, compare changes among body mass index (BMI) (kg/m2) groups, and examine how the changes were associated with adequacy of GWG defined using the 2009 Institute of Medicine guidelines.

Methods

Data came from a cohort of 360 pregnant women with measured anthropometric indicators (weight, midupper arm circumference, and skin folds of the triceps, thigh, and upper iliac) at <12-, 16 to 22-, and 28 to 32-wks of gestation. Fat gain was calculated using a formula. Analysis of variance was used to test for differences in anthropometric changes by BMI and adequacy of GWG in the third trimester. Multiple logistic regression was used to examine associations between changes in anthropometric indicators and GWG recommendations.

Results

Women with normal weight had greater increases in all anthropometric indicators, which differed from women with obesity, who had negative changes and gained less weight. Women who gained inadequately (21%) had negative changes that were all less, compared with women who gained adequately (46%) (except in upper iliac) or excessively (34%). Women with BMI of >25 who gained adequately also had negative changes. Logistic regression results indicated that changes in midupper arm circumference, triceps, and thigh skin folds, and fat gain were all inversely associated with inadequate GWG, whereas all indicators were positively associated with excessive GWG.

Conclusions

Anthropometric changes during pregnancy differ by BMI and are associated with adequacy of GWG. Women who gained adequately had minimal fat gain, lending support for current GWG guidelines.

No strong evidence of the protein leverage hypothesis in pregnant women with obesity and their infants

OBJECTIVE

The goal of this study was to investigate the role of dietary protein on macronutrient and energy intake, maternal adiposity during pregnancy, and infant adiposity at birth.

METHODS

In 41 women with obesity, early-pregnancy (13-16 weeks) protein intake was assessed with food photography and expressed as a ratio of Estimated Average Requirements (EAR) in pregnancy for protein (0.88 g/kg/d), herein "protein balance." Energy intake was measured by the intake-balance method, gestational weight gain as grams per week, and fat mass by a three-compartment model. Spearman correlations and linear models were computed using R version 4.1.1 (p < 0.05 considered significant).

RESULTS

Women had a mean (SD) age of 27.5 (4.8) years and a pregravid BMI of 34.4 (2.9), kg/m2 , and the majority were non-White (n = 23, 56.1%). Protein balance in early pregnancy was not significantly associated with energy intake across mid and mid/late pregnancy (β = 328.7, p = 0.30 and β = 286.2, p = 0.26, respectively) or gestational weight gain (β = 117.0, p = 0.41). Protein balance was inversely associated with fat mass in early, mid, and late pregnancy (β = -10.6, p = 0.01, β = -10.4, p = 0.03, β = -10.3, p = 0.03, respectively). Protein balance did not predict infant adiposity at birth (p > 0.05).

CONCLUSIONS

Low protein intake may have been present before pregnancy, explaining early relationships with adiposity in this cohort. The protein leverage hypothesis is likely not implicated in the intergenerational transmission of obesity.

Disease Course and Long-term Outcomes in Pregnant Women With Idiopathic Intracranial Hypertension: The IIH Prospective Maternal Health Study

BACKGROUND AND OBJECTIVES

Idiopathic intracranial hypertension (IIH) most typically occurs in women of childbearing age with increased weight as a key risk factor for development or exacerbation of the disease. Pregnancy is common in this group of patients. The longer-term effect of pregnancy on IIH has not been established and was the aim of this study.

METHODS

A prospective cohort study (IIH Life) recruited consecutive patients with IIH between 2012 and 2021 and evaluated outcomes including vision (logarithm of the minimum angle of resolution visual acuity, Humphrey visual field perimetric mean deviation, and optical coherence tomography [OCT] imaging) and headache. Four cohorts were evaluated: those with IIH diagnosed for the first time while pregnant, those with established IIH who became pregnant, those with a pregnancy prior to their diagnosis of IIH, and those with IIH who never became pregnant.

RESULTS

Three hundred seventy-seven people with IIH agreed to participate in the IIH Life maternal health study. Mean follow-up was 17.5 months (SD 20.5). IIH diagnosed in pregnancy was rare. Patients diagnosed with IIH while pregnant had greater papilledema (mean OCT total retinal thickness +11.59 µm/mo [95% CI 1.25-21.93]), although they had comparable visual field and acuity measures compared with those with established IIH who became pregnant during their disease course (-1.2 µm/mo [95% CI -2.6 to 0.21]). In those with established IIH, pregnancy did not adversely affect visual or headache outcomes over time, and the trajectory was akin to those with IIH who never had a pregnancy. Headache outcomes showed variability reflecting the IIH cohort as a whole.

DISCUSSION

A diagnosis of IIH while pregnant was rare but associated with more severe papilledema. Long-term visual outcomes in IIH were analogous irrespective of the timing of the pregnancy. These data are reassuring; however, close vigilance of IIH clinical features during pregnancy is recommended.

Pre-pregnancy body mass index has greater influence on newborn weight and perinatal outcome than weight control during pregnancy in obese women

BACKGROUND

The pre-pregnancy weight and gestational weight gain (GWG) are closely related to perinatal maternal and infant complications, but the relationship between pre-pregnancy weight and GWG and the pattern of interaction have not been reported. This study investigated the influence of weight control during pregnancy on the perinatal maternal and infant outcomes.

METHODS

A total of 835 singleton pregnant women who were hospitalized between January 2018 and December 2018 were retrospectively included in this study and divided into two groups: the diet guidance (DG) group (n = 167) and the control group (n = 668). The pre-pregnancy body mass index (BMI), GWG, and perinatal outcomes of the women and infants were determined in two groups.

RESULTS

The dietary modification and reasonable exercise during pregnancy effectively reduced the GWG, and even some women with pre-pregnancy obesity achieved weight loss during pregnancy. The GWG in the DG group was significantly lower than in the control group, especially in the second and third trimesters. GWG was positively related to birth weight. The birth weight in the DG group was significantly lower than in the control group when their mothers had similar GWG. In women with pre-pregnancy obesity, GWG seemed to be negatively related to birth weight. However, after adjusting the mean BMI, the pre-pregnancy BMI and GWG were positively related to the birth weight. Compared with the control group, the incidences of dystocia, postpartum hemorrhage, macrosomia, small for gestational age infants and neonatal complications significantly reduced in the DG group, and the preterm birth rate was comparable between two groups. Some women with pre-pregnancy obesity lose weight during pregnancy, but there was no premature birth or small for gestational age infant. The incidences of macrosomia, postpartum hemorrhage, dystocia, cesarean section and gestational diabetes increased significantly with the increase of pre-pregnancy BMI.

CONCLUSION

For women with increased pre-pregnancy BMI, strict weight control is required to reduce obesity-related complications of the mother and infant. The weight control in the second and third trimesters is especially important and most likely to prevent GWG. Compared with GWG, pre-pregnancy BMI has greater influence on the birth weight and maternal and infant complications, and may even compromise the benefits of weight control during pregnancy. Thus, weight control is recommended before pregnancy.

Gestational obesity: An unconventional endocrine disruptor for the fetus

Obesity has reached pandemic proportions and is a growing concern throughout the world. A parallel trend has also been observed among women in reproductive age, leading to the increasing global prevalence of gestational obesity (GO). The well-known obesity-related health problems also extend to pregnancy, where they are responsible for giving rise to a variety of medical and obstetrical complications, resulting in an increased incidence of adverse maternal and fetal outcomes. In this context, several epidemiological and clinical studies have shown that nutritional changes through different stages of gestation can have a substantial impact on the future health and development of the child. Therefore, it is clear that GO is a modifiable endocrine disruptor that negatively influences the health of the fetus and the newborn, with long-term metabolic implications. This review aims to describe the impact of GO on maternal and fetal outcomes using the available scientific literature and highlighting the evidence-based nutritional approaches currently recommended for the management of GO.

Variation in urine osmolality throughout pregnancy: a longitudinal, randomized-control trial among women with overweight and obesity

PURPOSE

Water needs increase during pregnancy, and proper hydration is critical for maternal and fetal health. This study characterized weekly hydration status changes throughout pregnancy and examined change in response to a randomized, behavioral intervention. An exploratory analysis tested how underhydration during pregnancy was associated with birth outcomes.

METHODS

The Healthy Mom Zone Study is a longitudinal, randomized-control trial intervention aiming to regulate gestational weight gain (GWG) in pregnant women with overweight/obesity (n = 27). Fourteen women received standard of care; 13 women additionally received weekly guidance on nutrition, physical activity, water intake, and health-promoting behaviors. Hydration status was measured weekly via overnight urine osmolality (Uosm) from ~ 8-36 weeks gestation; underhydration was dichotomized (Uosm ≥ 500 mOsm/kg). Gestational age- and sex-standardized birth weight and length z scores and percentiles were calculated. We used mixed-effect and linear regression models to test covariate-adjusted relationships.

RESULTS

No differences existed in Uosm or other characteristics between control and intervention women at baseline. Significant interactions (p = 0.01) between intervention and week of pregnancy on Uosm indicated intervention women maintained lower Uosm, whereas control women had a significant quadratic (inverse-U) relationship and greater Uosm in the second and early third trimesters. Results were consistent across robustness and sensitivity checks. Exploratory analyses suggest underhydration was associated with birth weight, but not length, in opposite ways in the second vs. third trimester.

CONCLUSION

A multi-component behavioral intervention helped women with overweight/obesity maintain better hydration throughout pregnancy. Future studies should confirm birth outcome results as they have important implications for early life nutrition.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03945266; registered May 10, 2019 retrospectively.

Maternal anthropometric measurements and correlation to maternal and fetal outcomes in late pregnancy

Background:

Body mass index does not distinguish between lean and fat body mass; therefore, its utility defining body composition is limited in pregnancy. Anthropometric measurements may better represent variation in body composition among women who are overweight or obese. We sought to examine body fat composition using maternal anthropometric measurements in late pregnancy and correlate with mode of delivery.

Methods:

A prospective study of pregnant patients who were overweight (body mass index: 25–29.9 kg/m²) or obese (body mass index ⩾ 30 kg/m²) with singleton pregnancies who underwent anthropometric measurements between 27 weeks, 0 days to 34 weeks, 6 days gestation. Maternal skinfold thicknesses from eight sites were used to estimate body fat mass. Correlation of skinfold thickness, anthroprometric measurements, and estimated body fat percentage on mode of delivery were analyzed with p < .05 as significant.

Results:

A total of 41 women with overweight (34.1%) or obese (65.9%) body habitus were included. Mean age was 29.9 years, and the majority (43.9%) were Black and 31.7% identified Hispanic/Latinx. The average gestational age at recruitment was 30 weeks, 2 days and 38 weeks, 6 days at delivery. A greater weight at recruitment (94.2 vs 81.8 kg, p = .023), waist circumference (47.1 vs 43.5 inches, p = .010), Huston–Presley body fat percentage (36.4% vs 31.8%, p = .030), triceps skinfold thickness (20.1 vs 15.7 mm, p = .030), biceps skinfold thickness (18.6 vs 15.0 mm, p = .042), and skinfold thickness, as well as sum of skinfold sites (83.3 vs 68.8 mm, p = .049) were associated with cesarean delivery compared to vaginal delivery on univariate analysis.

Conclusion:

Third-trimester anthropometric measurements may help predict increased risk for c-section in women with obesity. Further research may elucidate utility in nutritional counseling and delivery planning.

Analysis and Reliability of Anthropometric Measurements during Pregnancy: A Prospective Cohort Study in 208 Pregnant Women

Anthropometric assessment during pregnancy is a widely used, low-technology procedure that has not been rigorously evaluated. Our objective is to investigate fat mass distribution during pregnancy by examining changes in anthropometrics measures, in order to evaluate the reliability of these measures. An observational, longitudinal, prospective cohort study was performed in 208 pregnant women. Anthropometric measurements were taken following the ISAK protocol during the three trimesters and a generalized linear model for repeated measures was used to evaluate differences. Variability was assessed using the coefficient of variation, and Propagated Error (PE) was used to sum of skinfold thicknesses (SFT). SFT showed a general increase in fat mass during the three trimesters of pregnancy (∑SFT7 p = 0.003), and was observed in specific anatomical locations as well: arms (∑Arm SFT, p = 0.046), trunk (∑Trunk SFT, p = 0.019), legs (∑Leg SFT, p = 0.001) and appendicular (∑Appendicular SFT, p = 0.001). Anthropometric measures for skinfold thickness were taken individually during pregnancy and were reliable and reproducible during the three trimesters, which could help to prevent adverse pregnancy outcomes.

The relationship between gestational weight gain, maternal upper-body subcutaneous fat changes and infant birth size: A pilot observational study amongst women with obesity

BACKGROUND

It is widely acknowledged that maternal obesity and excessive gestational weight gain (GWG) are associated with increased risk of fetal macrosomia and recent studies have suggested a role for the timing and composition of GWG.

AIMS

To examine the effect of the rate of change in GWG and maternal upper-body subcutaneous fat on neonatal anthropometric outcomes in a pilot observational study amongst women with obesity.

STUDY DESIGN

Expectant women with a body mass index (BMI) > 30 kg/m² at first antenatal appointment were recruited at 12 weeks gestation. Maternal height, weight and skinfold thickness (SFT) measurements were collected at baseline and repeated at 28 and 36 weeks gestation. Following delivery, World Health Organisation (WHO)-UK infant birthweight z-scores were calculated, and infant anthropometric measurements were obtained.

RESULTS

The sum of upper body SFT measurements increased in mid-pregnancy (0.08 ± 0.71 mm/week) and decreased in late pregnancy (-0.04 ± 1.17 mm/week). After adjustment for maternal age, BMI and parity, mid- but not late- pregnancy GWG was positively associated with infant birthweight z-score (p<0.05), while mid- but not late-pregnancy changes in the sum of SFT were inversely associated with infant birthweight z-score (p<0.01).

CONCLUSIONS

The present study suggests that mid- rather than late-pregnancy changes in weight and upper-body subcutaneous fat are associated with infant birthweight. Further research is required in larger, more diverse populations to explore whether pregnancy interventions aiming to improve maternal and offspring health can be personalised beyond BMI and GWG.

Nutrition and Metabolic Adaptations in Physiological and Complicated Pregnancy: Focus on Obesity and Gestational Diabetes

Pregnancy offers a window of opportunity to program the future health of both mothers and offspring. During gestation, women experience a series of physical and metabolic modifications and adaptations, which aim to protect the fetus development and are closely related to both pre-gestational nutritional status and gestational weight gain. Moreover, pre-gestational obesity represents a challenge of treatment, and nowadays there are new evidence as regard its management, especially the adequate weight gain. Recent evidence has highlighted the determinant role of nutritional status and maternal diet on both pregnancy outcomes and long-term risk of chronic diseases, through a transgenerational flow, conceptualized by the Development Origin of Health and Diseases (Dohad) theory. In this review we will analyse the physiological and endocrine adaptation in pregnancy, and the metabolic complications, thus the focal points for nutritional and therapeutic strategies that we must early implement, virtually before conception, to safeguard the health of both mother and progeny. We will summarize the current nutritional recommendations and the use of nutraceuticals in pregnancy, with a focus on the management of pregnancy complicated by obesity and hyperglycemia, assessing the most recent evidence about the effects of ante-natal nutrition on the long-term, on either maternal health or metabolic risk of the offspring.

The UK Pregnancies Better Eating and Activity Trial (UPBEAT); Pregnancy Outcomes and Health Behaviours by Obesity Class

The effectiveness of antenatal intervention in women with increasing obesity is unknown. This study investigated whether there was a differential effect of antenatal intervention on diet, physical activity and pregnancy outcomes in women stratified by obesity class using data from the UK Pregnancies Better Eating and Activity Trial (UPBEAT) (n = 1555). The stratification was by World Health Organization classifications: Class I, II and III (30–34.9 kg/m², 35–39.9 kg/m² and ≥40 kg/m²). Using linear and logistic regression, adjusted for confounders, outcomes were assessed post-intervention (27⁺⁰–28⁺⁶ weeks’ gestation) and in late pregnancy (34⁺⁰–36⁺⁰ weeks’ gestation). Interactions between obesity class and the intervention were explored. Compared to the standard care arm, class III intervention women had lower gestational weight gain (GWG) (−1.87 kg; 95% CI −3.29 to −0.47, p = 0.009), and the effect of the intervention was greater in class III compared to class I, by −2.01 kg (95% CI −3.45 to −0.57, p = 0.006). Class I and II intervention women reported significantly lower dietary glycaemic load and saturated fat intake across their pregnancy. This differential effect of the intervention suggests antenatal interventions for women with obesity should stratify outcomes by obesity severity. This would inform evidence-based antenatal strategies for high-risk groups, including women with a BMI ≥ 40 kg/m².