title: Hemodynamic changes during twin pregnancy. A Doppler and M-mode echocardiographic study.
abstract: Serial hemodynamic investigations were performed in 10 women with twin pregnancies at 20, 24, 28, 32, and 36 weeks' gestation and at 6 months after delivery. Cardiac output was measured by Doppler and cross-sectional echocardiography at the aortic, pulmonary, and mitral valves. Cardiac chamber size and ventricular function were investigated by M-mode echocardiography. The hemodynamic results were compared with those of 13 women with singleton pregnancies. Mean Doppler cardiac output was increased at 20 weeks of twin pregnancy (7.63 L/min) and showed no significant change during the remainder of pregnancy, but fell to 5.07 L/min after delivery. This increase was significantly greater than that recorded during singleton pregnancy, because of a relatively greater increase in heart rate. Twin pregnancy was associated with a significantly greater increase in left atrial dimension, but the increases in left ventricular dimensions, wall thickness, and function were comparable to those recorded in singleton pregnancy.
authors.affiliation: Department of Obstetrics, University of Newcastle Upon Tyne, England.
authors.forename: S C
authors.initials: SC
authors.lastname: Robson
authors.forename: S
authors.initials: S
authors.lastname: Hunter
authors.forename: R J
authors.initials: RJ
authors.lastname: Boys
authors.forename: W
authors.initials: W
authors.lastname: Dunlop
mesh_terms: D002302:Cardiac Output; D004452:Echocardiography / Q000379:methods*; D015150:Echocardiography, Doppler; D005260:Female; D005865:Gestational Age; D006321:Heart / Q000033:anatomy & histology / Q000502:physiology; D006352:Heart Ventricles; D006439:Hemodynamics; D006801:Humans; D011247:Pregnancy; D011272:Pregnancy, Multiple / Q000502:physiology*; D014427:Twins