Serial changes in pulmonary haemodynamics during human pregnancy: a non-invasive study using Doppler echocardiography.
1. Serial pulmonary haemodynamic investigations were performed in 13 women before conception, at monthly intervals throughout pregnancy, and then at 6 months after delivery. 2. Mean pulmonary artery pressure was calculated from pulsed Doppler pulmonary velocities. Pulmonary flow was measured by Doppler and cross-sectional echocardiography. These two measurements were used to calculate pulmonary vascular resistance. 3. Mean non-pregnant pulmonary artery pressure was 13.8 mmHg and no significant change was demonstrated during pregnancy. 4. Pulmonary flow increased from 4.88 to 7.19 litres/min during pregnancy. 5. Pulmonary vascular resistance decreased from 2.85 resistance units before pregnancy to 2.17 resistance units at 8 weeks gestation. Thereafter there was no further significant change, values returning to pre-pregnant levels by 6 months after delivery.
Robson
S C
SC
Department of Obstetrics, University of Newcastle Upon Tyne, U.K.
Hunter
S
S
Boys
R J
RJ
Dunlop
W
W
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D049590:Postpartum Period / Q000502:physiology; D011247:Pregnancy / Q000502:physiology*; D011651:Pulmonary Artery / Q000502:physiology*; D011652:Pulmonary Circulation / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D014655:Vascular Resistance / Q000502:physiology