GYNAECOLOGICAL CAUSES OF ACUTE ABDOMINAL PAIN378 Obstetric and Gynaecological Emergencies
9 Request an ultrasound scan:
(i) Transabdominal (TA) ultrasound scan can demonstrate a
gestational sac within the uterus, which should be reliably
identified by 6 weeks. It may also show free intraperitoneal fluid
in free rupture
(a) absence of a gestational sac is suggestive of an ectopic
pregnancy
(b) the only exception to this rule is the rare heterotopic
pregnancy, with an intrauterine plus an ectopic pregnancy
(c) this occurs particularly in women undergoing assisted
reproductive technology treatment such as in vitro
fertilization (IVF).
(ii) Transvaginal (TV) ultrasound scan is more sensitive, and should
be able to show a gestational sac if the -hCG is >1000 IU,
or if the pregnancy is around 5 weeks, when the pregnancy is
intrauterine
(a) again, absence of a gestational sac is suggestive of an ectopic
pregnancy
(b) in addition, it should be able to identify most signs of the
extrauterine pregnancy itself.
(iii) Thus, ultrasound features suggesting an ectopic pregnancy
include an empty uterus, intrauterine pseudosac, a tubal ring,
adnexal mass and fluid in the pouch of Douglas.MANAGEMENT
1 Haemodynamically unstable ectopic pregnancy:
(i) Give high-flow oxygen by face mask and organize urgent cross-
match of 4 units of blood.
(ii) Commence an infusion of crystalloid such as normal saline or
Hartmann’s then blood, and refer the patient immediately to the
gynaecology team
(a) inform theatre and the duty anaesthetist.
2 Haemodynamically stable ectopic pregnancy:
(i) Stratify these patients on the basis of the ultrasound and -hCG
findings
(a) admit patients with a positive pregnancy test, empty uterus
on TV ultrasound examination and clinical signs of an
ectopic for a laparoscopyTip: a patient presenting with a positive pregnancy test, abdominal
pain, scanty vaginal bleeding and absence of intrauterine pregnancy on
ultrasound scan has an ectopic pregnancy until proven otherwise.✓