Bizarre blip: Cases of fetuses with flipped organs quadrupled in China

Enlarge / A nurse is on night shift at the emergency clinic of the International Peace Maternity & Child Health Hospital of China welfare institute in Shanghai, April 1, 2022. (credit: Getty | Yuan Quan)

Doctors in China are reporting a startling and unexplained spike in fetuses with situs inversus, a rare congenital condition in which the organs in the chest and abdomen are arranged in a mirror image of their normal positions.

In the first seven months of 2023, the rate of fetuses identified with the condition quadrupled compared with historic rates, according to a brief report appearing in the New England Journal of Medicine Thursday.

For the report, doctors from two big obstetric centers in the cities of Shanghai and Changsha combined their centers' clinical records from January 2014 through July 2023. The doctors found that from 2014 to 2022, the yearly total of situs inversus cases was typically about five to six per 10,000 pregnant people undergoing ultrasounds. But, in 2023, the rate jumped to nearly 24 cases per 10,000 ultrasound screenings.