When it comes to pregnancy and race things might get a little complicated according to a new study published in the American Journal of Obstetrics and Gynecology.

The study by researchers at the Lucile Packard Children’s Hospital and Stanford University School of Medicine found that rates of cesarean deliveries, gestational diabetes and other pregnancy risks differ among Asian, Caucasian and interracial Asian-Caucasian couples.

For the study, the researchers analyzed data from white, Asian and Asian-white couples who delivered at the Johnson Center for Pregnancy and Newborn Services at Packard Children’s from 2000 through 2005 – 5,575 white, 3,226 Asian and 868 Asian-white couples.

It found that white mother/Asian father couples had the lowest Caesarean rate of 23 percent, while Asian mother/white father couples had the highest rate at 33.2 percent. This might be related to the fact that the average Asian woman’s pelvis may be smaller than the average white women’s and less able to accommodate babies of a certain size.

When it comes to gestational diabetes, Asian-Caucasian couples were 2.4 and 2.6-times more likely to be affected by the disease compared to Caucasian couple, depending on whether the mother was Caucasian or Asian. Gestational diabetes is a known risk factor for Asian-Asian couples.

Looking at birth weights, the researchers found that they were lowest for Asian couples (7.07 lb), highest for Caucasian couples (7.49 lb) and intermediate for mixed couples (7.40 lb for Asian-mother/white father and 7.32 lb for white-mother/Asian-father).

“Our study demonstrates that interracial Asian-Caucasian couples represent a population with distinct perinatal risks, with differing risks depending upon which parent is of Asian race,” the study concluded.