# Obesity and Sleep Apnea in Pregnancy

> **NIH NIH R01** · UT SOUTHWESTERN MEDICAL CENTER · 2021 · $687,584

## Abstract

Maternal obesity is a major risk factor for adverse pregnancy outcomes (e.g., preeclampsia, 
gestational diabetes, preterm birth, etc.). This increased risk is attributed, at least in part, to 
obstructive sleep apnea (OSA), defined as an Apnea and Hypopnea Index (AHI) ≥5. Obese mothers with 
OSA are at a very high risk for complicated pregnancies. However, it is unknown if the increased 
risk of OSA is due to being obese at the onset of pregnancy or to excessive weight gain during 
pregnancy. In addition, the mechanism(s) by which obesity-related OSA creates increased 
pregnancy risk are also unknown. Obesity, OSA, and pregnancy per se are all associated with 
sympathetic activation. Whether maternal obesity and OSA increase the risk of adverse pregnancy 
outcomes through sympathetic neural mechanisms needs to be determined. In addition to the 
sympathetic nervous system, the natriuretic peptide system also contributes significantly to 
cardiovascular health and disease. Corin is a transmembrane protease discovered in the heart 
where it converts pro-atrial natriuretic peptide to active atrial natriuretic peptide, a cardiac 
hormone that regulates salt-water balance and blood pressure (BP). Corin has been suggested to be 
involved in the pathogenesis of preeclampsia. Conversely, obese adults were found to have an 
increased corin content. Whether corin can be used as a biomarker for obesity and/or OSA related 
pregnancy risk needs to be investigated. The overall objectives of this research are 1) to compare 
the impact of obesity versus excessive gestational weight gain on OSA in obese and nonobese women; 
2) to investigate the mechanism(s) by which obesity and OSA increase cardiovascular risk during 
pregnancy; and 3) to identify biomarker(s) for obesity-related OSA in pregnant women. To accomplish 
these objectives, we will enroll early pregnant (≤8 wks. of gestation) obese (pre-pregnancy BMI ≥30 
kg/m2) and nonobese (BMI 18.5-24.9 kg/m2) women and follow them throughout gestation. In-home sleep 
testing will be carried out during early pregnancy and will be repeated between weeks 30-32 of 
gestation. We will compare AHI, the development or worsening of OSA, and pregnancy outcomes in 
obese and nonobese women with and without weight gain above the Institute of Medicine recommended 
levels (Aim 1). We will also use the state-of-the-art technique of microneurography to measure 
resting sympathetic activity and sympathetic neural responses to physiological stimulations during 
early and late (32-34 wks.) pregnancy, and postpartum (6-10 wks. post) in obese women with and 
without OSA and nonobese women without OSA (Aim 2). Finally, venous blood samples will be taken in 
women enrolled in Aim 2 for measurements of serum corin content and pregnancy-specific angiogenic 
factors. The relationships between corin, pregnancy-specific angiogenic factors, sympathetic 
activity, and BP will be explored (Aim 3). Information gained will increase our understan...

## Key facts

- **NIH application ID:** 10213820
- **Project number:** 5R01HL142605-04
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **Principal Investigator:** QI FU
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $687,584
- **Award type:** 5
- **Project period:** 2018-09-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10213820

## Citation

> US National Institutes of Health, RePORTER application 10213820, Obesity and Sleep Apnea in Pregnancy (5R01HL142605-04). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10213820. Licensed CC0.

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