Severe Morning Sickness Could Indicate 'It's Girl'
February 7, 2000
Throughout history, expectant mothers have attempted to predict the sex of their babies. While today's modern technology has replaced the fortuneteller, a woman may be able to predict her baby's sex just by the way she's feeling. Swedish researchers have found that severe nausea and vomiting in the first trimester of pregnancy, known in medical terms as hyperemesis gravidarum, may be indicative of a female baby.
Hyperemesis gravidarum is associated with higher levels of a hormone called human chorionic gonadotropin (hCG). Since the levels of hCG increase at the time of birth of a female fetus, Swedish researchers from Stockholm's Karolinska Institute hypothesized that there may be a link between morning sickness and baby's sex.
The researchers examined the records of all Swedish births between 1987 and 1995. Of more than one million infants born during that period, 51 percent were girls and 49 percent boys. They compared those figures to the records of women who were hospitalized for hyperemesis gravidarum during the first trimester of their pregnancy and found that the ratio had changed. Fifty-six percent of these women gave birth to girls, while only 44 percent delivered boys. The change in ratio accounted only for women suffering from hyperemesis gravidarum in the first trimester. For women hospitalized during the second or third trimesters, the girl/boy ratio reflected the national average.
Reporting the results of their study in the December 11, 1999, issue of The Lancet, the researchers write that their findings are compatible with sex-related differences in hormone concentrations. However, since the hormone levels of the hospitalized pregnant women were not measured, they cannot claim to have proven their hypothesis. So until there is more conclusive data, don't prepare for a girl based solely on the presence of severe morning sickness.
"Even among the women with hyperemesis gravidarum," says Johan Askling, M.D., the study's lead investigator, "the magnitude of the altered sex ratio in the offspring is so small that in an individual case, one may just as well toss a coin."