Lead exposure and association with angiogenic factors and hypertensive disorders of pregnancy.

Abstract

Lead exposure has been associated with hypertensive disorders of pregnancy. Angiogenic factors, including soluble fms-like tyrosine kinase 1 (sFlt1) and placental growth factor (PlGF), are aberrant in preeclampsia, but have not been correlated with lead levels. We evaluated the association of lead exposure with angiogenic factors. This cross sectional study utilized a convenience sample of singleton pregnancies ≥34weeks' gestation. Blood lead and angiogenic factors were measured before delivery; bone lead was measured postpartum. We dichotomized bone and blood lead into the top tertile versus the bottom tertiles and used log-binomial regression to assess the association between lead and a high angiogenic ratio. The outcomes were high sFlt1 to PlGF ratio and development of a hypertensive disorder of pregnancy. We enrolled 102 participants, of whom 98 had at least one lead measurement and an angiogenic factor result. Median bone lead was 3.8 ug/g (2.0 - 6.6) and median blood lead was 0.2 ug/dL (0.2 - 0.4). Incidence of hypertensive disorders of pregnancy was 31%. When comparing the highest tertile of bone lead to the bottom two tertiles, there was no association with a high sFlt1/PlGF ratio or hypertensive disorders of pregnancy. Similar results were observed for the exposure of blood lead. Lead exposure was not an important contributor to an elevated angiogenic factor ratio or hypertensive disorders of pregnancy in our U.S. However, lead exposure was modest in our population and we cannot exclude a relationship with hypertensive disorders of pregnancy.