Nitric oxide donors: effects on fetoplacental blood flow.
OBJECTIVE
To investigate fetal and uteroplacental blood flow after transdermal administration of glyceroltrinitrate (GTN) in pregnancies at risk for preterm delivery.


METHODS
Twenty-five pregnant women who received GTN patches (Nitroderm TTS 10) with a dosage of 0.8 mg/h, because of risk for preterm delivery, were included in the prospective study. Doppler measurements (resistance index, RI) of the umbilical artery (UA), the middle cerebral artery (MCA) and the uterine arteries of the placental (UTA-P) and the non-placental (UTA-NP) side, with calculation of the mean-RI (UTA-mean), were performed before and after 24, 48 and 72 h of the 1st GTN application. Wilcoxon test and Holm correction were used for statistical analysis.


RESULTS
The initial RI values were in the normal range. Significant decreases of the RI of UTA-NP ( P = 0.02 ) and UTA-mean ( P = 0.03) were observed 24h after GTN application. The other RI values did not show significant changes.


CONCLUSIONS
Transdermal nitroglycerine used for the treatment of preterm labour does only reduce uterine vascular impedance at the non-placental side with primary higher resistance. It does not affect fetal perfusion and uterine perfusion at the placental side with normal blood flow resistance.
Kähler
Chistiane
C
Department of Obstetrics and Gynaecology, Friedrich Schiller University Jena, Bachstr. 18, 07740 Jena, Germany. chistiane.kaehler@med.uni-jena.de
Schleussner
Ekkehard
E
Möller
Arne
A
Seewald
Hans-Joachim
HJ
D001158:Arteries / Q000187:drug effects / Q000502:physiology; D005260:Female; D005333:Fetus / Q000098:blood supply; D005865:Gestational Age; D006801:Humans; D020030:Nitric Oxide Donors / Q000009:adverse effects*; D005996:Nitroglycerin / Q000009:adverse effects*; D007752:Obstetric Labor, Premature / Q000188:drug therapy; D021041:Placental Circulation / Q000187:drug effects*; D011247:Pregnancy; D011446:Prospective Studies; D015149:Tocolytic Agents / Q000009:adverse effects*; D014599:Uterus / Q000098:blood supply; D014655:Vascular Resistance / Q000187:drug effects
D020030:Nitric Oxide Donors; D015149:Tocolytic Agents; D005996:Nitroglycerin