Are women carrying "basketballs" really having boys? Testing pregnancy folklore

Antenatal ascertainment of fetal sex is a common feature of modern pregnancies. Women who opt not to learn fetal sex typically employ a variety of methods to forecast it. This study investigated the validity of prevalent folklore used to identify fetal sex before birth.

One hundred four pregnant women, who did not know the sex of the fetus, were administered a questionnaire to explore their perceptions of fetal sex and the basis for these predictions.

Fetal sex was not systematically related to the shape of the woman's abdomen, prevalence of morning sickness, or comparisons with previous pregnancies. However, women who had more than twelve years of education correctly predicted fetal sex greater than chance (71% correct), in contrast to less educated women (43% correct). Contrary to expectations, women whose forecasts were based on psychological criteria (i.e., dreams or feelings) were more likely to be correct than those employing prevalent folklore criteria (i.e., the way a woman was carrying the pregnancy).

In general, women were not good predictors of fetal sex. The mechanisms that promote maternal accuracy in predicting fetal sex for highly educated women are unknown. It is reasonable to expect that maternal perceptions of fetal sex contribute to the process of fetal attachment.