Maternal thromboxane and prostacyclin levels in relation to fetal birth weight.
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.


METHODS
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(1alpha) (6-keto-PGF(1alpha)). 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(1alpha) and the TXB(2)/6-keto-PGF(1alpha) ratio.


RESULTS
Trend analysis showed higher TXB(2) levels and higher TXB(2)/6-keto-PGF(1alpha) ratios in patients with SGA versus AGA newborns. No statistically significant difference in 6-keto-PGF(1alpha) excretion between patients with SGA and AGA newborns was detected.


CONCLUSIONS
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.
de Jong
C L
CL
Department of Obstetrics and Gynecology, University Hospital Vrije Universiteit, Postbus 7057, 1007 MB, Amsterdam, The Netherlands. dejong-speelman@wxs.nl
Paarlberg
K M
KM
van Geijn
H P
HP
van Kamp
G J
GJ
van Dis
H
H
Dekker
G A
GA
D015121:6-Ketoprostaglandin F1 alpha / Q000097:blood*; D000328:Adult; D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D011225:Pre-Eclampsia / Q000097:blood; D011247:Pregnancy; D013929:Thromboxane B2 / Q000097:blood*
D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha