Pre-pregnant Prediction of Recurrent Preeclampsia in Normotensive Thrombophilic Formerly Preeclamptic Women Receiving Prophylactic Antithrombotic Medication

Abstract

Background

Both hemodynamic abnormalities and thrombophilia predispose to pregnancy-associated vascular complications such as fetal growth restriction, stillbirth, preeclampsia, and placental abruption. Antithrombotic treatment may reduce the risk for these events. In this study we tested the hypothesis that in normotensive thrombophilic formerly preeclamptic women certain alterations in hemodynamic function as measured under nonpregnant conditions predict the development of hypertensive disorders and / or fetal growth restriction in the subsequent pregnancy.

Methods

In 350 nondiabetic formerly preeclamptic women, we measured in the follicular phase of the menstrual cycle at least 5 months postpartum central hemodynamic, metabolic, and hemostatic variables. In the subsequent ongoing pregnancy we determined fetal outcome variables and the incidence of maternal vascular complications. In addition to a normotensive thrombophilic profile, inclusion for final analysis required a subsequent singleton pregnancy, established within 1 year following the pre-pregnant evaluation and ongoing beyond 16 weeks’ gestation. As a consequence, 47 normotensive thrombophilic formerly preeclamptic women could be included for final analysis. All formerly preeclamptic participants received aspirin throughout pregnancy. Additionally, those with thrombophilia or hyperhomocysteinemia were treated with low molecular weight heparin and with pyridoxine and folic acid supplementation, respectively.

Results

Among 350 formerly preeclamptic women, 266 (76%) were normotensive and 84 (24%) hypertensive. About half (140/2 66) of normotensive formerly preeclamptic participants were thrombophilic. One hundred eighteen formerly preeclamptic participants succeeded in establishing an ongoing pregnancy within 1 year. From this subset of formerly preeclamptic women, 47 were normotensive thrombophilic; 23 remained normotensive (THROMB), whereas 24 developed at least gestational hypertension (COMPLITHROMB). Participants in the latter subgroup were more obese than those remaining normotensive. In addition, this former subset of women had a higher vascular resistance index, and a lower plasma volume and cardiac index. With respect to fetal outcome, COMPLITHROMB gave birth to an infant with a lower birth weight relative to THROMB. Preeclampsia with or without the hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome recurred in 26% of the participants in the whole thrombophilic group, in which a low pre-pregnant plasma volume and a raised vascular resistance predisposed for recurrent hypertensive disorders.

Conclusion

Pre-pregnant hemodynamic, metabolic, and clotting variables in formerly preeclamptic women can predict hypertension in the subsequent pregnancy.