Maternal thromboxane and prostacyclin levels in relation to fetal birth weight

Abstract

Objective: To analyse whether pregnancies resulting in a small for gestational age neonate are preceded by a prostacyclin deficiency or an imbalance between thromboxane and prostacyclin. Study design: At five fixed time points during pregnancy, 24-h urine samples were collected for the measurement of thromboxane and prostacyclin metabolites thromboxane-B 2 (TXB 2) and 6-keto-prostaglandin F 1α (6-keto-PGF 1α). In order to study trend differences between pregnancies with appropriate (AGA; n=26) and small for gestational age neonates (SGA; n=17), trend analysis with simple contrasts were accomplished for TXB 2, 6-keto-PGF 1α and the TXB 2/6-keto-PGF 1α ratio. Results: Trend analysis showed higher TXB 2 levels and higher TXB 2/6-keto-PGF 1α ratios in patients with SGA versus AGA newborns. No statistically significant difference in 6-keto-PGF 1α excretion between patients with SGA and AGA newborns was detected. Conclusion: The birth of an SGA neonate is not preceded by prostacyclin deficiency. With ongoing pregnancy an imbalance between thromboxane and prostacyclin becomes more obvious in pregnancies with SGA newborns.