PONTIAC (WWJ) -The Oakland County Medical Examiner’s office says a 28-year-old Pontiac woman died of an enlarged heart.

Officials say they were called to a home where the woman, who was pregnant with twins, was unresponsive.

Paramedics performed CPR on her, and took her to a local hospital, where she, along with her two fetuses, were pronounced dead.

The woman did not have a medical history. But the Medical Examiner’s office says an enlarged heart occurs in the last two months of pregnancy for women having twins.