Fetal hemodynamic response to maternal intravenous nicotine administration.
OBJECTIVE
Our study was designed to test the hypothesis that maternally administered nicotine has significant effects on fetal hemodynamics and umbilical systolic/diastolic ratios.


METHODS
Nine pregnant ewes received maternal intravenous infusions of 10, 20, and 30 micrograms/kg/min of nicotine. Maternal and fetal blood pressure, heart rate, and uterine and umbilical blood flow were recorded.


RESULTS
Maternal intravenous administration of nicotine (10, 20, and 30 micrograms/kg/min of maternal body weight) produced significant (p < 0.05) increases in fetal blood pressure (2%, 11%, and 25%, respectively), decreases in fetal heart rate (0%, 8%, and 12%), and decreases in umbilical blood flow (0%, 0%, and 19%). Umbilical systolic/diastolic ratios increased slightly at the 30 micrograms/kg/min dose of nicotine, but these changes did not reach significance. Maternal blood pressure increased (10%, 25%, and 53%), and uterine vascular resistance increased (5%, 64%, and 344%) significantly (p < 0.05); uterine blood flow increased at the 10 micrograms/kg/min dose (+5%) and decreased by 23% and 42% at the highest two doses of nicotine.


CONCLUSIONS
Maternal nicotine administration in late-term pregnant sheep produced significant increases in fetal arterial blood pressure and umbilical vascular resistance, decreased fetal heart rate, and umbilical blood flow but did not significantly alter systolic/diastolic ratios.
Clark
K E
KE
Department of Obstetrics and Gynecology, University of Cincinnati College of Medicine, OH 45267-0526.
Irion
G L
GL
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D005333:Fetus / Q000187:drug effects* / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects*; D007275:Injections, Intravenous; D008431:Maternal-Fetal Exchange; D009538:Nicotine / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000097:blood* / Q000502:physiology; D012039:Regional Blood Flow / Q000187:drug effects; D012756:Sheep; D014470:Umbilical Cord / Q000098:blood supply; D014599:Uterus / Q000098:blood supply; D014655:Vascular Resistance / Q000187:drug effects
D009538:Nicotine