ABSTRACT
Bleeding in the first trimester of pregnancy may occur in one-fifth of all pregnancies, of which nearly half miscarry. The incidence of spontaneous abortion/miscarriage is estimated at 15–22 per cent of all pregnancies. It is thus a commonly encountered problem due to a variety of causes, which can be classified as obstetric or non-obstetric. The site of implantation occurs in the fundus or body of the uterus in the majority of pregnancies. However, sometimes it may implant in the lower segment and, as the lower uterine segment stretches to accommodate the growing sac, there may be bleeding. In patients with early pregnancy bleeding there may be ultrasound evidence of retrochorionic collection of blood. This is analogous to abruptio placentae in late pregnancy. This bleeding may vary in amount but may resolve spontaneously in many instances, allowing the pregnancy proceed normally thereafter.
