PP037. Family history of cardiovascular disease and maternal vascular function during early pregnancy

Women with a family history of cardiovascular disease (CVD) have an increased risk of hypertensive disorders during pregnancy. Pregnancy is associated with increased physical demands on the cardiovascular system and hemodynamic changes. Cardiac output increases by about 40-50%, blood volume by 10-20% and vascular resistance decreases.

Our hypotheses was that women with a family history of CVD fail to have an adequate cardiovascular adaptation during pregnancy.

Fifty healthy women with singleton viable pregnancies were included in the study who were recorded in the Ultrasound Department of UltraGyn Stockholm, Sweden for ultrasound dating in gestational week of 11-14. Of these, 25 women had a family history of CVD which was defined as having at least one first degree relative with the diagnosis of premature hypertension, myocardial infarct or stroke before the age of 55 (men) or 65 (women). Twenty five healthy women without a family history were included as controls. Smokers were excluded. Blood pressure was measured in the upper left arm in a conventional way. The pulse wave was registered in the radial artery (SphygmoCor Px and Vx, PWV Medical). The central blood pressure was calculated with a validated algorithm. The pulse wave was then registered in the femoral artery, the velocity was calculated and the arterial stiffness estimated. Flow mediated vasodilation was studied in the radial artery through measurement with ultrasound of diameter changes and blood flow before and after ischemia (Vivid 7, GE, 10MHz transducer).

Systolic blood pressure in the upper left arm was significantly higher in women with a family history of CVD (median 109.5mmHg versus 105mmHg, p=0.04). Diastolic blood pressure did not differ. Aortic blood pressure also differed significantly in women with a family history of CVD, both systolic (median 95mmHg versus 86.3mmHg, p=0.0005) and diastolic (median 66mmHg versus 59.3mmHg, p=0.0024). No other results were significantly different. All values refer to examinations at gestational weeks 11-14.

Changes in vascular function during the first trimester reflect important adaptations that are necessary for a normal pregnancy. Women with a family history of CVD had a significantly higher blood pressure at 11-14weeks of gestation although the values were within normal range. The pregnancy related decrease of vascular resistance may be less pronounced in women with a family history of CVD. Vascular function will be followed longitudinally during pregnancy and related to obstetric outcome in this group.