ABSTRACT
Over the past three decades, there has been an alarming increase in the incidence of childhood obesity.
Childhood obesity leads to early onset of cardiovascular risk factors, and both obesity and cardiovascular risk
factors track into adulthood and contribute to the epidemic of cardiovascular disease (CVD). The Developmental
Origins of Health and Disease theory posits that risk for obesity and CVD is, in part, programmed in utero. To
prevent this early entrenchment into obesity and CVD, identification of modifiable maternal factors during
pregnancy that later impact offspring risk in early childhood is essential. A surprising lack of research investigates
the role of prenatal sedentary behavior (SED), moderate-to-vigorous-intensity physical activity (MVPA), and the
novel 24-hour behavior paradigm (the composition of SED, physical activity, and sleep) on these adverse
offspring outcomes. This is a critical research gap because there is strong physiological rationale that SED,
MVPA, and 24-hour behavior in pregnancy could influence offspring health, and these behaviors are modifiable
targets for intervention during pregnancy. The overall goal of this proposal is to examine the associations of SED
(Aim 1) and MVPA (Aim 2) across pregnancy with offspring obesity risk and CVD risk through 24 months. We
will also use novel statistical methods to determine the optimal 24-hour behavior compositions (Aim 3) during
pregnancy associated with reduced risk of these adverse offspring outcomes. We can achieve these aims by
leveraging our ongoing, multi-center cohort study Pregnancy 24/7 (R01 HL153095), where we are prospectively
measuring SED, physical activity, and sleep in 500 women in each trimester of pregnancy using state-of-the-art
monitors (activPAL3 micro and Actiwatch Spectrum Plus). Pregnancy 24/7 also assesses other relevant prenatal
exposures that may associate with offspring obesity and CVD risk, i.e., pre-pregnancy obesity, gestational weight
gain, diet, smoking, and adverse pregnancy outcomes. In direct response to the NHLBI’s Notice of Special
Interest (NOT-HL-19-695), we propose to expand Pregnancy 24/7 by conducting a separate cohort study among
the offspring of its participants. In the Offspring Study, we propose to combine maternal exposure data from
Pregnancy 24/7 with new, comprehensive assessments of postnatal exposures, obesity, and CVD risk measures
in the child through 24 months via medical record abstraction, questionnaires, and an in-person study visit at 24
months. We hypothesize that offspring of women with higher SED or lower MVPA across pregnancy will have
more rapid increases in BMI Z-score (primary outcome), and greater adiposity, blood pressure, and pulse wave
velocity through 24 months. Further, we hypothesize that statistically reallocating time in SED to physical activity,
but not sleep (among adequate duration sleepers) will be associated with more optimal offspring outcomes. By
combining prenatal and postnatal exposure data, our approach uniquely allows us to isolate the effects of
pregnancy SED, MVPA, and 24-hr behavior on offspring obesity and CVD risk measures in early childhood. This
project will inform critically needed primordial prevention interventions to decrease the risk of obesity and CVD.
