Excretion of prostacyclin and thromboxane metabolites before, during, and after pregnancy-induced hypertension

Abstract

The aim of the present study was to assess whether changes in prostacyclin (PGI 2) and thromboxane (TXA 2) generation precede the manifestation of pregnancy-induced hypertension (PH). The metabolites 6-oxo-PGF 1α and TXB 2 were measured in the urine of 69 randomly selected pregnant women from 16–20 weeks of gestation (wg) until delivery and more than 6 weeks postpartum. Between 16–20 and 21–24 wg 6-oxo-PGF 1α excretion did not change in patients who later developed PIH ( n = 6) but increased significantly in the control group ( n = 63). In contrast, a marked rise in TXB 2 excretion was found in the PIH group but not in controls. Thereafter significant differences between both groups persisted from 25 wg until delivery. The 6- oxo- PGF 1α TXB 2 ratio was below the 10th percentile from 21–24 wg until delivery in patients with developing PIH. The excretion of both metabolites was substantially lower in the non-pregnant state without any difference between patient groups. These results show an altered urinary excretion of both 6-oxo-PGF 1α and TXB 2 preceding the onset of the disease. A pathophysiological role of PGI 2 deficiency and increased TXA 2 formation in PIH appears substantiated.