our present findings , together with data obtained from animal models , suggest that cigarette smoking during pregnancy induces fetal hypoxia through two independent but additive pathways : ( 1 ) an acute effect is caused by nicotine activation of adrenergic discharge , resulting in vasoconstriction , a decreased uterine perfusion , and a consequent transient fetal tachycardia , and ( 2 ) a delayed but prolonged increase in hbco may cause a sustained reduction of fetal oxygenation .
C0032961
pregnancy
C0028040
nicotine