Early pregnancy assessment

Background
Approximately 1:300 pregnancies (1:100 in inner city areas) are outside the womb (extra uterine), the vast majority in the fallopian tube. The ampulla or isthmus of the tube (See Gynaesurgeon.co.uk - Anatomy & Physiology) is the most common site, typically resulting in a woman presenting with pain and bleeding (>95%) between 6 and 8 weeks gestation (dated from the first day of her last period). If the pregnancy is in the cornua of the fallopian tube, it may enlarge and present around 11 -13 weeks gestation. Where the ectopic has ruptured there will be signs of peritonism (blood in the abdomen causing irritation) or haemodynamic collapse, but the majority of women present before such catastrophic events take place.

Investigation
A positive urinary pregnancy test confirms that the patient has conceived. A careful history and examination remains an essential first step in the assessment of early pregnancy problems. Ultrasound and HCG values must always be evaluated in light of the clinical evidence, otherwise mistakes are made and unnecessary interventions or discharges take place.

Ultrasound
The nearer an ultrasound beam is to the organ to be investigated, the better the resolution of the images obtained. (Continued next page)