Objective: Most women with a pregnancy complicated by preeclampsia have either hypertension or a disorder with a thrombophilic phenotype or both of these. In this study we evaluated whether hemodynamic variables and volume homeostasis in a subgroup of normotensive women with a history of preeclampsia with normal clotting function (defined as the symptom-free subgroup) were comparable with those in a healthy parous control group.
Study design: In a group of 58 subjects with a history of preeclampsia and a group of 11 healthy parous control subjects we measured the following variables > or = 5 months post partum at day 5 +/- 2 of the menstrual cycle: body weight and length, mean arterial pressure, heart rate, cardiac output, plasma volume, glomerular filtration rate, effective renal plasma flow, and plasma concentrations of volume regulatory hormones, clotting factors, antiphospholipid antibodies, and homocysteine before and after a methionine load. From the measured data we calculated body mass index, body surface area, cardiac index, left ventricular work, total peripheral and renal vascular resistances, effective renal blood flow, and renal filtration fraction.
Results: Among women with a history of preeclampsia 26 were normotensive with thrombophilia (45%), 14 had hypertension (24%), and 18 were normotensive without thrombophilia (31%). These last symptom-free subjects with a history of preeclampsia were more obese than were control subjects. They also had higher cardiac output and left ventricular work and a lower plasma volume than the healthy parous control subjects. Thus they resemble the second subgroup of subjects (subjects with hypertension and a history of preeclampsia) rather than the control subjects. The hemodynamic and renal functions in the subgroup of subjects with a history of preeclampsia with normotension and thrombophilia were similar to those in healthy parous control subjects.
Conclusion: On the basis of this study we conclude that hemodynamic parameters and volume homeostasis in the symptom-free subgroup of women with a history of preeclampsia are different from those in healthy parous control subjects. Hemodynamic parameters and volume homeostasis in this subgroup resemble those of women with hypertension and a history of preeclampsia. We therefore propose the classification of these symptom-free subjects with a history of preeclampsia as having "latent" hypertension.