Parameters of fetal pulmonary vascular health: baseline trends and response to maternal hyperoxia in the second and third trimesters

• Published in: Ultrasound in obstetrics & gynecology Vol. 50; no. 5; pp. 618 - 623
• Main Authors: Yamamoto, Y., Hirose, A., Howley, L., Savard, W., Jain, V., Hornberger, L. K.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.11.2017; Wiley Subscription Services, Inc
• Subjects: Adult; Digital divide; Doppler; Echocardiography; Echocardiography, Doppler - methods; Ejection; Female; Fetus - embryology; Fetus - physiopathology; Fetuses; Gestation; Gestational Age; Healthy Volunteers; Humans; Hyperoxia; Hyperoxia - diagnostic imaging; Hyperoxia - embryology; Hyperoxia - physiopathology; Hypoplasia; lung growth; Lungs; maternal hyperoxia; Pregnancy; Pregnancy Complications, Cardiovascular - diagnostic imaging; Pregnancy Complications, Cardiovascular - etiology; Pregnancy Complications, Cardiovascular - physiopathology; Pregnancy Trimester, Second - physiology; Pregnancy Trimester, Third - physiology; Prospective Studies; Pulmonary arteries; Pulmonary artery; Pulmonary Artery - diagnostic imaging; Pulmonary Artery - embryology; Pulmonary Artery - physiopathology; Reversed flow; Ultrasonography, Prenatal - methods; Variability; Vascular Resistance - physiology; pulmonary artery; Doppler; maternal hyperoxia; lung growth
• ISSN: 0960-7692; 1469-0705
• DOI: 10.1002/uog.17383

ABSTRACT Objectives Several parameters, including branch pulmonary artery (PA) diameter and Doppler‐derived PA acceleration‐to‐ejection time ratio (AT/ET), peak late‐systolic/early‐diastolic reversed flow (PEDRF) and pulsatility index (PI) response to maternal hyperoxia, have been used to investigate fetal pulmonary health. Lower AT/ET, increased PEDRF and lack of PI response to hyperoxia have been observed in fetuses with severe lung hypoplasia and are considered markers of pulmonary vascular resistance. We sought to further define the evolution of PA diameter and Doppler parameters and their response to maternal hyperoxia in healthy fetuses. Methods Fifty‐four prospectively recruited women with healthy pregnancy underwent fetal echocardiography from 18–36 weeks of gestation. After baseline branch PA diameter and Doppler assessment, oxygen (8–10 L/min) was administered by non‐reservoir facemask for 10 min and PA Doppler parameters were reassessed. Results Branch PA diameters and AT/ET increased linearly with gestational age, while PEDRF increased quadratically (P < 0.001 for all) and PA‐PI did not change. In response to maternal hyperoxia, although most fetuses demonstrated a significant decrease in PI for both branch PAs (right PA, P = 0.025; left PA, P = 0.040) ≥ 30 weeks, significant variability was observed in PI response with 31% of cases demonstrating either no response or a slight decrease. No other parameter demonstrated a measurable change in response to maternal hyperoxia. Conclusions From the mid‐trimester, fetal branch PA diameters and AT/ET increase linearly and PEDRF increases quadratically, whereas PI remains unchanged. Although maternal hyperoxia triggers a significant decrease in PA‐PI after 30 weeks, variability in this response may reduce its utility in clinical practice. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.