Spontaneous preterm birth with placental maternal vascular malperfusion is associated with cardiovascular risk in the fifth decade of life.

Women with a history of spontaneous preterm birth (SPTB) have a mildly elevated cardiovascular risk (CVR) later in life and women with a history of preeclampsia have a highly elevated CVR. In placentas of women with preeclampsia pathological signs of maternal vascular malperfusion (MVM) are often seen. These signs of MVM are also seen in a substantial part of the placentas of women with SPTB. We therefore hypothesize that in women with a history of SPTB, the subgroup with placental MVM has an elevated CVR. This study is a secondary analysis of a cohort study including women 9-16 years after a SPTB. Women with pregnancy complications known to be associated with CVR were excluded. The primary outcome was hypertension defined as blood pressure ≥ 130/80 mmHg and/or treatment with antihypertensive medication. Secondary outcomes were mean blood pressure, anthropometrics, blood measurements including cholesterol and HbA1c, and creatinine in urine. Placental histology was available in 210 (60.0%) women. MVM was found in 91 (43.3%) of the placentas, most often diagnosed by the presence of accelerated villous maturation. Hypertension was diagnosed in 44 (48.4%) women with MVM and in 42 (35.3%) women without MVM (aOR 1.76, 95% CI 0.98 - 3.16). Women with a SPTB and placental MVM showed significantly higher mean diastolic blood pressure, mean arterial pressure and HbA1c approximately 13 years after delivery, compared to women with a SPTB without placental MVM. We therefore conclude that placental malperfusion in women with a SPTB might differentiate in CVR later in life.