• To identify site(s) of pregnancy, e.g. intrauterine, interstitial or ectopic

• To detect early pregnancy failure

• To predict outcome in the presence of a live embryo

• To assess gestational age

• To determine the number of embryos and assess horionicity and amnionicity

• To diagnose gestational trophoblastic disease

• To diagnose fetal anomalies

The diagnosis of fetal anomalies is limited by the resolution of ultrasound but gross anomalies such as cystic hygromas and large cranial cysts are detected

• To assess associated maternal abnormalities, e.g. ovarian cysts, uterine leiomyomas.