Risk Estimation and Prediction of Preeclampsia, IUGR, and Thrombosis in Pregnancy

The aim of this thesis was to improve background knowledge for making a reliable medical evaluation at the first visit of a woman in her 13th gestational week, to the antenatal clinic. We have focused on the prediction and the risk estimation of preeclampsia, intra-uterine growth restriction (IUGR), and thrombosis.

The thesis was based on five studies, in which we have evaluated biochemical analyzes, genetic tests, anamnestic information, and statistical information (based on the data from medical files and from the Swedish Medical Birth and Hospital Discharge Registers).

High maternal urine human chorionic gonadotropin level in early pregnancy was associated with a 3-fold increased risk of preeclampsia, vis-à-vis low values, while low epidermal growth factor levels were associated with IUGR pregnancies.

Maternal smoking was associated with an increased risk of thrombosis (Odds ratio (OR)=1.24; 95% Confidence interval (CI) 1.02-1.51), which was consumption dependent. Moderate smoking was associated with lower incidence of preeclampsia associated with preterm birth in both study series (OR=0.1; CI 0.01-0.7, and OR=0.6; CI 0.5-0.8, respectively).

Apart from an 1.1% risk of thrombosis, APC resistance was not associated with preeclampsia, IUGR, or spontaneous abortion. However, the carriers of APC resistance had fewer profuse hemorrhages at delivery (3.7% vs. 7.9%), which might have given them an evolutionary advantage, explaining the high prevalence (10.7%). The incidence of pregnancy-associated thrombosis in Sweden was 13/10000, evenly distributed in the ante- and postpartum periods. APC resistance was associated with an 8-fold increased risk of thrombosis. Overweight, heredity of thrombosis, and cesarean delivery were all associated with a roughly 5-fold increased risk of thrombosis. Preeclampsia was associated with a 3-fold increased risk of thrombosis in the postpartum period.