Body composition changes in pregnancy: measurement, predictors and outcomes

Area of Science:

• Reproductive Health
• Human Physiology
• Body Composition Analysis

Background:

• Rising rates of overweight and obesity in the US have increased pregravid body mass index and gestational weight gain.
• Pregnancy introduces physiological complexities that challenge standard body composition estimation methods.
• Existing methods often fail to accurately distinguish maternal composition from fetal and supporting tissues, leading to potential errors.

Purpose of the Study:

• To review commonly used and available methods for assessing maternal body composition changes during pregnancy.
• To discuss factors influencing maternal body composition and their impact on maternal and offspring outcomes.
• To provide recommendations for future research in pregnancy body composition assessment.

Main Methods:

• Review of established and emerging techniques including anthropometry, total body water, densitometry, imaging, dual-energy X-ray absorptiometry, bioelectrical impedance, and ultrasound.
• Evaluation of the strengths and limitations of each method in the context of pregnancy.
• Consideration of factors affecting maternal body composition and long-term outcomes.

Main Results:

• Many methods provide only whole-body estimates of fat and fat-free mass, with limited ability to measure regional adipose tissue changes.
• Several techniques are prone to error due to violated assumptions, particularly regarding fat-free mass hydration during pregnancy.
• The review highlights the need for improved methodologies to accurately assess maternal body composition.

Conclusions:

• Accurate assessment of maternal body composition during pregnancy remains a significant challenge.
• Further research is needed to develop and validate methods that can reliably measure maternal body composition changes.
• Improved assessment methods are crucial for understanding the impact of body composition on maternal and offspring health.