Fetal response to maternal exercise in pregnancies with uteroplacental vascular insufficiency

Abstract

To determine the fetal response to sub-maximal maternal exercise at 22-26 weeks in pregnancies with abnormal uterine artery Doppler. A prospective matched cohort-control study was undertaken. Twelve singleton pregnancies with bilateral uterine artery notching and mean uterine pulsatility index (PI) values >1.45 at 22-26 weeks of gestation were evaluated. Matched controls (n = 23) were clinically normal and had normal uterine artery Doppler. Maternal and fetal cardiovascular responses to 5 minutes of steady state cycling at 10% and at 15% of maximum predicted work rate were evaluated by ultrasound/Doppler. Baseline characteristics were similar between the 2 groups. No differences in either resting or in exercise-induced maternal or fetal cardiac parameters were found between the 2 groups. There was no difference between the basline umbilical artery PI values for cases and controls but the difference became significant post exercise (P = .02 after the 10% load and P = .006 after the 15% load). Of the 12 cases, 6 subsequently developed preeclampsia, 5 had SGA fetuses, 2 of which developed absent end-diastolic flow velocity (AEDF) and early-onset intrauterine growth restriction (IUGR). Mean gestational age at delivery was 33 weeks vs. 40 weeks in the controls (P = .001). 3/12 (25%) cases developed transient (AEDF) in umbilical artery Doppler after the exercise that recovered after cessation of exercise, compared with none of the controls. 2/3 of these subsequently developed AEDF and IUGR. Sub-maximal steady state exercise may have transient deleterious effects in a subset of women with uteroplacental vascular insufficiency. These findings may impact on advice regarding physical activity in this sub-group of women. Dynamic testing such as maternal exercise may be of value in identifying pregnancies that adapt poorly to uteroplacental vascular insufficiency.