THE BELIEF: Morning sickness means a baby girl is more likely.
THE FACTS: Old wives' tales about predicting a baby's sex -- relying on clues like the way the woman carries and the fetal heart rate -- are usually more fantasy than fact.
But the notion that morning sickness can sometimes indicate that a girl is on the way may be an exception. A number of large studies in various countries have examined the claim, and almost all have found it to be true, with caveats. Specifically, studies have found that it applies to women with morning sickness in the first trimester, and with symptoms so severe that it leads to hospitalization, a condition known as hyperemesis gravidarum.
One of the most recent studies was conducted by epidemiologists at the University of Washington. The scientists compared 2,110 pregnant women who were hospitalized with morning sickness in their first trimester and a control group of 9,783 women who did not get severely ill. They found that the women in the first group were more likely to deliver a girl, and that those who were the sickest -- hospitalized for three days or more -- had the greatest odds: an increase of 80 percent compared with the control women.
Other studies in The Lancet and the journal Epidemiology, among others, have repeated the findings. It is thought that certain hormones produced by female fetuses may be the culprit.
THE BOTTOM LINE: Severe morning sickness may indicate a higher likelihood that the baby will be a girl.
-- The New York Times