GAINESVILLE---When a number of studies appeared during the 1980s and 1990s showing that cigarette smoking decreased a woman's risk of certain diseases, scientists were stunned.
"The possibility that smoking could have a protective effect on pre-eclampsia, a sometimes life-threatening condition in pregnancy, was the exact opposite of what you would predict," said Kathleen Shiverick a professor of pharmacology and therapeutics at the University of Florida College of Medicine. "And other studies had shown a surprising decrease in the rates of uterine cancer and endometriosis, which sometimes causes infertility."
Those results prompted Shiverick and Dr. Carolyn Salafia, a professor of pathology and pediatrics at Columbia University College of Physicians and Surgeons, to undertake a comprehensive review of the medical literature. In articles to be published next month in the journal Placenta, they have concluded that the protective effects are more mirage than reality.
Pre-eclampsia, a sometimes fatal condition for mother and baby whose symptoms include high blood pressure, is less common among smokers because many of their troubled pregnancies are redirected into miscarriages, according to Salafia and Shiverick.
When pregnancies do continue past the first trimester, there still can be problems.
"Smoking damages blood vessels," Salafia said. "The vessels get so beaten up that they may not be able to respond to a damaged placenta with the high blood pressure characteristic of pre-eclampsia. This may 'protect' the mother. But the baby is still at risk because the placenta is damaged, and there is increased risk of pre-term birth and abruption, both of which can be lethal to the baby."
And while endometriosis and uterine cancer may be less common among
smokers, the reproductive system in such women is far from normal, leading
to such problems as decreased production of eggs, difficulties becoming
Contact: Victoria White
University of Florida