Early identification of an abnormal pregnancy is important. The diagnosis o
f ectopic pregnancy before tubal rupture can prevent life-threatening hemor
rhage. This article provides a review of the normal development in early pr
egnancy and correlates this with ultrasound findings, followed by a structu
red approach to the ultrasound examination. The specific findings in early
pregnancy are reviewed, and the predictive value of these findings in ident
ifying either a normal or abnormal intrauterine pregnancy or an ectopic pre
gnancy are discussed.