Maternal cardiovascular function at 35–37 weeks' gestation: relation to maternal characteristics

Objective To examine the possible effects of maternal characteristics and obstetric and medical history on maternal cardiovascular parameters at 35–37 weeks' gestation. Methods In 3013 singleton pregnancies at 35–37 weeks, maternal characteristics and medical history were recorded; uterine artery pulsatility index, mean arterial pressure (MAP) and maternal cardiovascular parameters were measured. Multivariable regression analysis was used to determine significant predictors of the cardiovascular parameters among gestational age (GA), maternal characteristics and medical history. Results Multivariable regression analysis demonstrated that significant independent prediction of log 10 cardiac output and log 10 cardiac power was provided by GA, maternal age, weight, weight gain from the first trimester, height, racial origin, smoking, assisted conception and previous neonatal birth‐weight Z ‐score in parous women. For log 10 total peripheral resistance, significant prediction was provided by GA, maternal age, height, racial origin, chronic hypertension, diabetes mellitus, assisted conception, previous neonatal birth‐weight Z ‐score and prior pre‐eclampsia (PE) in parous women. For log 10 stroke volume, significant prediction was provided by maternal age, height, racial origin, smoking, chronic hypertension and diabetes mellitus. For heart rate, significant prediction was provided by GA, weight, weight gain, height, racial origin, chronic hypertension, previous neonatal birth‐weight Z ‐score and prior PE in parous women. For log 10 MAP, significant prediction was provided by maternal weight, racial origin, family history of PE, chronic hypertension and diabetes mellitus. For log 10 thoracic fluid capacity, significant prediction was provided by GA, maternal age, weight, height, racial origin and systemic lupus erythematosus or antiphospholipid syndrome. For log 10 ventricular ejection time, significant prediction was provided by GA, weight, height and racial origin. Conclusion Maternal cardiovascular parameters are affected by maternal characteristics and medical and obstetric history, and they should therefore be converted into multiples of the normal median adjusted for significant independent predictors before their inclusion in combined screening for PE.