Effect of maternal age on cardiac adaptation in pregnancy

Objective To compare longitudinal maternal hemodynamic changes throughout gestation between different age groups. Methods This was a prospective longitudinal study assessing maternal hemodynamics using a bioreactance technique at 11+ 0 to 13+ 6, 19+ 0 to 24+ 0, 30+ 0 to 34+ 0 and 35+ 0 to 37+ 0weeks' gestation. Women were divided into four groups according to maternal age at the first visit at 11+ 0 to 13+ 6weeks: Group 1, < 25.0 years; Group 2, 25.0- 30.0 years; Group 3, 30.1-34.9 years; and Group 4, = 35.0 years. A multilevel linear mixed-effects model was performed to compare the repeat measurements of hemodynamic variables, correcting for demographics, medical and obstetric history, pregnancy complications, maternal age and gestational-age window. Results The study population included 254 women in Group 1, 442 in Group 2, 618 in Group 3 and 475 in Group 4. Younger women (Group 1) had the highest cardiac output (CO) and lowest peripheral vascular resistance (PVR), and older women (Group 4) had the lowest CO and highest PVR throughout pregnancy. The higher CO seen in younger women was achieved through an increase in heart rate alone and not with a concomitant rise in stroke volume. Although the youngest age group demonstrated an apparently more favorable hemodynamic profile, it had the highest incidence of a small-for-gestational-age neonate. There was no significant difference between the groups in the incidence of pre-eclampsia. Conclusion Age-specific differences in maternal hemodynamic adaptation do not explain the differences in the incidence of a small-for-gestational-age neonate between age groups. (C) 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Automated summary

The study found that younger women have higher cardiac output and lower peripheral vascular resistance during pregnancy, while older women have lower cardiac output and higher peripheral vascular resistance. Although younger women exhibited a more favorable hemodynamic profile, they also had a higher incidence of small-for-gestational-age neonates.