Charlotte Iacobaeus

Longitudinal study of vascular structure and function during normal pregnancy

To examine alterations in maternal vascular structure and function during normal pregnancy.

Fetal growth is associated with first‐trimester maternal vascular function

To investigate the relationship between maternal endothelial function in the first trimester, assessed in both the brachial artery and the forearm skin microcirculation, and fetal growth.

Pregnancy‐associated plasma protein‐A is positively correlated with first‐trimester skin microvascular reactivity

To investigate the relationship between levels of circulating maternal pregnancy‐associated plasma protein‐A (PAPP‐A) and first‐trimester maternal vascular function.

A2. A longitudinal study of endothelial function during normal pregnancy

Abstract Aim: This study aimed to examine alterations in maternal endothelial function during normal pregnancy. Methods: We assessed endothelial function in the brachial artery (by post-ischemic hyperemia-induced flow-mediated vasodilation and glyceryl nitrate) and in the forearm skin microcirculation (by laser Doppler perfusion imaging and iontophoretic administration of acetylcholine (Ach) and sodium nitroprusside (SNP)) in 53 healthy primiparous women at 14, 24 and 34 weeks of gestation, and nine months post-partum (non-pregnant state). Results: Flow-mediated vasodilation in the brachial artery (FMD) increased during early pregnancy, whereas nonspecific vasodilatation by glyceryl trinitrate (GTN) decreased, indicating improved endothelial function. Consistent with this, endothelium-dependent skin microvascular reactivity to Ach also increased. Discussion: Normal pregnancy is associated with increased endothelial function assessed both in the brachial artery and in the forearm skin microcirculation.

PP001. The vascular tree during pregnancy and at follow-up – A longitudinal study of maternal vascular function

INTRODUCTION Normal maternal vascular function and optimal cardiovascular adaptation to the increasing demands of pregnancy is a prerequisite for a successful outcome of pregnancy. How different levels of the vascular tree react and interact during pregnancy has not been fully investigated previously but may be determined by genetic as well as maternal, fetal and environmental factors. OBJECTIVE To investigate how different levels of vascular function change during the course of pregnancy and relate these levels to each other. METHODS Healthy non smoking women with singleton pregnancies and a viable embryo recorded at the ultrasound departments of UltraGyn Stockholm, Sweden were recruited. The following cardiovascular examinations were performed: examination of structural changes of the heart: Echocardiography of the heart with Doppler examination and tissue Doppler. Examination of macrocirculation, vessel structure and function plus endothelial function: Intima-media thickness of the common carotid artery, pulse wave velocity, central blood pressure and flow mediated vasodilation. Examination of microvascular function in the skin and endothelial function: total circulation of the skin and capillary flow in nails. The microcirculation before, during and after iontophoresis with nitroprussid and acetylcholine. The investigations were performed in gestational week 11-14, 22-24, 36 and 9 months post partum. RESULTS In total 35 participants had a normal course of pregnancy. Curves of the development of the various cardiovascular variables will be presented according to gestational age and their place in the vascular tree. CONCLUSIONS These curves will be used to investigate how various determinants such as blood pressure, fetal growth and body mass index, as well as fetal sex affects and are affected by cardiovascular function in pregnancy.

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

INTRODUCTION 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. OBJECTIVES Our hypotheses was that women with a family history of CVD fail to have an adequate cardiovascular adaptation during pregnancy. METHODS 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). RESULTS 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. CONCLUSION 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.

OS083. Fetal growth and maternal vascular function in early pregnancy

INTRODUCTION Increasing evidence indicates that the rate of fetal growth is partly determined already in the first half of pregnancy. A number of authors have reported that if the fetus is smaller than expected at dating, the risk for a small for gestational age fetus increases. OBJECTIVES To investigate if maternal vascular function in early pregnancy reflects fetal growth in the first trimester. METHODS Fifty healthy women with singleton viable pregnancies were included in the study that were recorded the ultrasound department of UltraGyn Stockholm, Sweden for ultrasound dating in gestational week 11-14 . Of these, 25 women had their estimated date of delivery postponed ⩾ 7 days at ultrasound dating compared to last menstrual period in gestational week 11-14. As controls 25 women were fetal size were in accordance with the last menstrual period (defined as expected date of delivery moved less than six days) were recruited. The dating examinations were performed by specially trained midwives. To assess gestational age, biparietal diameter was used. Exclusion criteria were the use of oral contraceptives within three months before conception, uncertain date of the last menstrual period, irregular menstrual periods, fetuses that were ⩾ 21 days larger or smaller than expected, and fetal anomalies. Women that smoked were also excluded. Blood pressure was measured in the upper arm in a conventional way. The central blood pressure was calculated with a validated algorithm. Changes in skin microcirculation were measured using laser Doppler fluxmetri (LDF). Both endothelial dependent dilatation using assessment of acetylcholine (Ach) and local warming of skin to 44C for maximum micro vascular hyperaemia (MMH) and non endothelial dilatation using assessment of sodium nitroprusside (SNP) was examined. RESULTS Fetuses that were smaller than expected at ultrasound dating compared to last menstrual period at gestational week 11-14, had an increased change in maximum micro vascular hyperaemia (p=0.034). There was no significant correlation between ACh-response (p=0.59) and SNP-response (p=0.23). No differences were seen in blood pressure. CONCLUSION In the first trimester, changes in vascular function might reflect important adaptations that are required to facilitate normal fetal growth. This was highlighted by the findings of a positive correlation between fetal growth at 11-14 weeks gestation and changes in endothelial dependent microcirculation. Vascular function of these women will be followed longitudinally during pregnancy and related to obstetric outcome. If changes in microcirculation in the first trimester correlates to an increased risk for complications such as hypertensive disorders during pregnancy or intrauterine growth restriction this gives new insights into the early phase of these complications.