WIP 82 - Body Composition in Low-Birth-Weight Preterm Infants Born to Mothers with Hypertensive Disorders

Poster Number: WIP 82
Publication Number: WIP 82.2368

Background: Maternal hypertensive disorders (MHDs) are present in 3-10% of all US pregnancies, with pre-eclampsia accounting for up to 25% of growth-restricted and small-for-gestational age infants. Early nutritional management of this population may be important for mitigating long-term sequela such as elevated blood pressure and BMI later in life. Understanding the effect MHDs have on infant body composition (BC) may enable optimization of nutritional management of these infants in the NICU.

Objective: To determine the effect of MHDs on preterm infant BC. We hypothesize that exposure to MHDs negatively impacts infant BC, resulting in higher fat mass and lower fat free mass accretion.

Design/Methods: In this prospective cohort study, IRB STUDY004649, we used air displacement plethysmography via the Peapod® to compare the BC of preterm, low-birth-weight infants born to mothers with and without hypertensive disorders. Goal enrollment is 128 preterm infants to achieve a level of significance of 0.05 with a power of 80%.

Weight, length, head circumference, and BC were measured at 36 weeks corrected gestational age or discharge. Weight, length, fat mass, fat-free mass, and percent fat and fat-free mass were compared using t-test for equality of means when equal variances are assumed using Levene’s Test for Equality of Variances.

To date, 69 preterm infants have been enrolled and 45 have completed the study. Maternal and infant baseline characteristics are similar between both groups. Preliminary results demonstrate that preterm infants with maternal hypertension exposure are born smaller in weight (1.03 kg vs 1.29 kg, p= 0.02), length (35.6 cm vs 38.3 cm, p=0.02), and head circumference (25.0 cm vs 26. 7 cm, p= 0.02) but have higher body mass (2.88 kg vs 2.59 kg, p=0.05), fat mass (0.27 kg vs 0.19 kg, p= 0.04), and percent fat mass (8.7% vs 6.8%, p= 0.05) as well as lower percent fat free mass (91.3% vs 93.4%, p= 0.04) at term.

Early data suggest that MHDs are associated with altered preterm infant BC, particularly higher fat mass and lower fat-free mass at term.