Heartbeat at 6 weeks how likely is a miscarriage?

Pregnancy: With a fetal heart rate at 6 weeks the chances of miscarriage are reduced significantly: to around 3 to 5%. Factors which increase the risk of miscarriage include prior obstetric history (like if the patient has had recurrent miscarriage), any systemic medical illnesses. And advanced maternal age. Good prenatal care is important to improve the chances of a successful pregnnacy.