Maternal smoking reduces prostacyclin formation in human umbilical arteries. A study on strictly selected pregnancies.

Production of prostacyclin (PGI2)-like activity in umbilical arteries in vitro was evaluated in 38 selected newborn infants. Nineteen of the mothers of these infants were habitual smokers and the remaining 19 were non-smokers. To rule out the possibility of disturbing effects of drugs or other factors, the newborn infants and their mothers fulfilled strict criteria regarding normality and control of drug intake. The infants of habitual smokers (greater than 5 cigarettes/day) (n=19) were compared with a control group (n = 19) with non-smoking mothers. Smokers' babies had lower birth weights than the controls (3,500 +/- 440 vs 3,900 +/- 420 g, p less than 0.001). Production of PGI2-like activity was estimated by a bioassay technique. Umbilical arteries of smokers' infants produced significantly less PGI2-like activity (139 +/- 78 ng/g arterial tissue) than those of the controls (201 +/- 87 ng/g) (p less than 0.05). As expected, the two groups differed highly significantly regarding serum levels of markers for exposure to cigarette smoke, but these levels did not correlate to formation of PGI2. Decreased production of PGI2-like activity in umbilical vessels might have an impact on nutritive blood flow and oxygen transport, especially in situations of asphyxia.