A 26-year-old woman, G1P0, at 14 weeks’ gestation comes to the physician for her first prenatal visit. Her past medical history is significant for unexplained bruisability that has occurred once or twice a year since childhood. Physical examination shows a uterus consistent with 14 weeks’ gestation. Laboratory studies show:
Bleeding time: 8 minutes
Prothrombin time: 14 seconds
Partial thromboplastin time: 34 seconds
This patient’s fetus is at greatest risk for which of the following?