WASHINGTON, D.C., March 31, 2008: Having sons is important to many Asian cultures, and now American families from those groups seem to be asserting the same preference. A new analysis of the 2000 Census shows that among U.S. born children of Chinese, Korean and Asian Indian parents the odds of having a boy increase if the family already has a girl or two. The findings “suggest that in a sub-population with a traditional son preference, the technologies are being used to generate male births when preceding births are female,” co-authors Douglas Almond and Lena Edlund said of their findings, appearing in Tuesday’s edition of Proceedings of the National Academy of Sciences.
Edlund and Almond said they do not know what method is being used for sex selection, but they speculated that the most common is fetal ultrasound to determine the sex of the baby followed by disproportionate abortion of females. Ultrasound has improved in recent years and is being given earlier, they noted.
“Between 1989 and 1999, prenatal ultrasound use among non-Japanese Asian mothers rose from around 38 percent to 64 percent of pregnancies,” they said, citing data from the U.S. National Center for Health Statistics. The normal sex ratio at birth is 1.05 boys to 1 girl and that holds for first children of these families, the researchers found. But if the first baby is a girl, the odds of a boy coming next rise to 1.17-to-1, and after two sisters the likelihood of having a son jumps to 1.51-to-1.
The American College of Obstetricians and Gynecologists and the American Society of Reproductive Medicine say assisting patients in choosing the sex of their offspring to avoid serious sex-linked genetic disorders is ethical, but they discourage sex selection for personal and family reasons, such as family balancing. Nevertheless, while many countries prohibit sex selection techniques without a medical purpose, the United States does not.