*4.1. Participants*

The study sample included 35 women with a history of preeclampsia (PE), 38 women with uncomplicated pregnancies (UP), and 51 age-matched women without gestation during the last three years (CO). Women with preceding pregnancy (PE and UP groups) were asked to participate in the study 13–15 weeks postpartum and were tested 15–17 weeks after delivery.

For twenty-one women with an uncomplicated pregnancy (UP), it was their first child (while in PE, *n* = 22); for 14, it was their second child (in PE, *n* = 10); for two, it was their third child (in PE, *n* = 3); and for one woman, it was her fourth child. Parity did not differ between women with uncomplicated pregnancies and women with a history of preeclampsia (χ<sup>2</sup> = 1.9, *p* = 0.59). Of the 35 PE pregnancies, 19 were diagnosed with mild PE and 16 had symptoms of severe PE. In 6 PE pregnancies, gestation was terminated before 34 weeks (early PE), between weeks 34 and 37 (preterm preeclampsia) in 14 PE pregnancies, and 15 children were delivered after 37 weeks (term PE). One woman with a history of preeclampsia, two women with uncomplicated pregnancies, and 15 women without gestation were smokers. All women were of Caucasian ethnicity. Characteristics of the study sample are presented in Table 5.


**Table 5.** Characteristics of the participants (mean ± SD, range), and statistical differences.

**1,2,3** Denotes a significant difference between PE (1), UP (2), and CO (3) based on Bonferroni-corrected post-hoc tests. BMI: body mass idex.

Preeclampsia was confirmed using the recommendations of the American College of Obstetricians and Gynecologists Task Force on Hypertension in Pregnancy (2013) [74]. Inclusion criteria were: Systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg, presenting at ≥20 weeks gestation and returning to normotensive values within 12 weeks postpartum, blood pressure measured twice and at least 4 h apart. Proteinuria: either protein ≥300 mg per 24 h urine collection, or protein/creatinine ratio ≥0.3, or protein ≥30 mg/dL or 1+ on urine dipstick. Severe preeclampsia was confirmed in the same way as preeclampsia, as defined above, except one of the following had to be present and proteinuria was not required: (1) systolic blood pressure ≥160 mmHg, measured twice at least 15 min apart; (2) diastolic blood pressure ≥110 mmHg, measured twice at least 15 min apart; (3) thrombocytopenia: platelet count <100,000/microliter; (4) impaired liver function: AST or ALT

≥70 units/L or twice the normal concentration; (5) renal insu fficiency: serum creatinine ≥1.1 mg/dL or doubled from baseline values; (6) pulmonary edema; or (7) symptoms indicating possible cerebral or neurologic involvement: headache or visual changes (e.g., flashing, blurring, visual loss, blindness). Participants with uncomplicated pregnancies had singleton pregnancies with term delivery. Exclusion criteria in both groups with preceding pregnancy and the age-matched women without gestation were: diabetes mellitus, renal disease, chronic hypertension, antiphospholipid antibody syndrome, kidney transplant, hypothyroidism, thyroid antibodies, pre-existing cardiovascular problems, and seizures. Women with multiple gestations or substance abuse (alcohol, tobacco, illegal drugs) were also excluded.

Written informed consent was provided for all participants included in the study. The study was approved by the authorized ethics committee, Medical University Graz, Austria (No. 27-515 ex 14/15, *Pregnancy complications: challenge and*/*or chance for further cardiovascular risk in later life?*, date of approval: 14 September 2015) and the Ethics committee Carinthia, Austria (No. A16/15, *Pregnancy complications: challenge and*/*or chance for further cardiovascular risk in later life?*, date of approval: 10 September 2015)
