The feasibility of prospectively studying maternal cardiovascular changes from before conception

There is compelling evidence that factors before pregnancy and around implantation may have a bearing on maternal cardiovascular adaptation to pregnancy and subsequent pregnancy outcome. Prospective studies from before pregnancy are associated with difficulties in recruitment, low conception rates, early pregnancy loss and low retention of participants during pregnancy and postpartum follow-up. The objective of this study was to establish the feasibility of recruiting to; conducting and completing a prospective cohort study from before pregnancy to the postpartum period. One-hundred and forty-three women planning to conceive were recruited. They underwent detailed cardiovascular measurements including brachial and central blood pressures, cardiac output, aortic stiffness and pulse wave reflection, metabolic function and platelet aggregation. Once pregnant, the cardiovascular assessments were repeated at intervals throughout pregnancy and postpartum. Of 143 women, 101 women conceived within 18 months. Seventy-one had viable pregnancies at 10-14 weeks. Among the 70 live-births, three women developed preeclampsia (PE) and two had intrauterine growth restriction. Two were lost to follow-up. It is feasible to recruit women who are planning to conceive, conduct prepregnancy cardiovascular assessments and follow them up during pregnancy. Based on the current data, approximately half the women recruited will have healthy ongoing pregnancies. This information would allow the design of a study, powered for pregnancy complications such as PE, to enable investigation of the 'cause and effect' relationship between abnormal cardiovascular function and pregnancy complications.