Ectopic pregnancy and bleeding in early pregnancy

Essentials

1
Approximately 25% of all clinically diagnosed pregnancies are associated with bleeding in the first 12 weeks, of which approximately 50% of cases will be due to a failed pregnancy.
2
Ectopic pregnancy occurs at a rate of around 11:1000 diagnosed pregnancies.
3
The management of ectopic pregnancy and failed pregnancy may be surgical, medical or conservative.

Introduction

Bleeding in early pregnancy is a common problem affecting approximately 25% of all clinically diagnosed pregnancies, and, of these, approximately 50% will have bleeding due to a failed pregnancy. Other causes of bleeding include ectopic pregnancy and molar pregnancy; however, most bleeding is incidental or physiological and has no bearing on the outcome of the pregnancy.

Terminology

The terminology used to describe early pregnancy bleeding conditions is defined as follows.

Miscarriage

A miscarriage is defined as pregnancy loss occurring before 20 completed weeks’ gestation or a foetus less than 400 g weight, if the gestation is unknown.

Threatened miscarriage

A threatened miscarriage is any vaginal bleeding other than spotting before 20 weeks’ gestation.

Inevitable miscarriage

Inevitable miscarriage is a miscarriage that is imminent or in the process of happening.

Complete miscarriage

A complete miscarriage is when all products of conception have been expelled.

Failed pregnancy

A failed pregnancy is defined on ultrasound criteria. These include the finding of a crown rump length (CRL) greater than 6 to 10 mm with no cardiac activity or a gestational sac equal to or greater than 20 to 25 mm with no foetal pole (previously referred to as an anembryonic pregnancy or a blighted ovum).

A failed pregnancy may then remain in the uterus (previously termed a missed abortion) or may progress to either an incomplete or complete miscarriage, as defined by the presence or absence of pregnancy-related tissue in the uterus.

Pregnancy of unknown location

A pregnancy of unknown location refers to the situation where the beta subunit of human chorionic gonadotrophin (β-hCG) is elevated, but no pregnancy can be identified on ultrasound.