Effects on the course of the pregnancy and fetal development:
(1) increased abruption
(2) increased rates of preterm delivery
(3) increased rates of spontaneous abortion
(4) fetal growth retardation with lower birthweights (often 200-400 grams)
(5) an increase in minor fetal malformations
(6) decreased risk of pre-eclampsia
Effects on the placenta:
(1) vasoconstriction with reduced blood flow and hypoxic damage
(2) slightly lower weight
(3) higher rate for infarcts
(4) higher rate of single umbilical artery (two vessel cord)
(5) increased calcifications
(6) reduced villus size
The adverse effects increase with the number of cigarettes smoked per day and are marked when > 20 are smoked per day. Environmental smoke may also contribute to adverse effects.
Differential diagnosis:
(1) other substances of abuse (alcohol, cocaine, etc)
Use of nicotine replacement will have some effect on the pregnancy because of nicotine's vasoactive effects, but there would be less exposure to other toxins.
