First Trimester Bleeding & Ectopic Pregnancy

Differential Diagnoses

• Pregnancy-related causes including miscarriage (threatened, incomplete or missed), ectopic pregnancy and gestational trophoblastic disease

• Cervical causes such as cervical polyps, cervical ectropion and cervical cancer

• Infections including pelvic inflammatory disease and cervicitis or vaginitis (eg chlamydia, gonorrhoea)

• Other causes such as implantation bleeding occurring 10–14 days post-conception

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Assessment

• Evaluate haemodynamic stability and assess the degree of pain and blood loss

• Perform a detailed history to determine gestational age, symptom duration and associated features such as syncope, chest pain or shoulder tip pain

• Ensure a qualitative urinary pregnancy test is undertaken in all women of reproductive age with unexplained abdominal pain

• Recognise that significant blood loss may occur before overt signs of instability emerge

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Investigations

• Transvaginal ultrasound to assess pregnancy location, viability and to identify adnexal masses or free fluid

• Serial serum β-hCG measurements with an expected doubling every 48–72 hours in a normal intrauterine pregnancy; plateaued or suboptimal rise suggests ectopic or non-viable pregnancy

• Qualitative urinary hCG testing as a rapid and cost-effective screening tool

• Complete blood count to evaluate for anaemia or infection

• Blood group and antibody screen to determine Rh status and the need for anti-D immunoglobulin

• Pelvic examination including speculum and bimanual exam to assess cervical dilation, lesions or the source of bleeding

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Risk Factors for Ectopic Pregnancy

• Previous ectopic pregnancy or tubal surgery (eg ligation, reversal)

• Prior pelvic inflammatory disease or history of sexually transmissible infections

• Assisted reproductive techniques (eg IVF) and conception despite an intrauterine device in situ

• Smoking, age over 35 and endometriosis

• Note that up to one-third to one-half of ectopic pregnancies occur without recognised risk factors

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Management

• Immediate transfer to hospital for haemodynamically unstable patients or those with signs of rupture

• For ectopic pregnancy in stable patients, consider medical management with methotrexate when criteria are met (eg hCG <5000 IU/L, adnexal mass <3.5 cm without fetal cardiac activity)

• Surgical management via laparoscopy is indicated for unstable patients, suspected rupture, failed medical management or contraindications to methotrexate, with salpingectomy or salpingostomy as appropriate

• Management of miscarriage depends on clinical scenario (threatened, inevitable, incomplete or missed) and may involve expectant, medical or surgical approaches with appropriate follow-up to confirm complete resolution

• Administer Rh D immunoglobulin for Rh-negative patients within 72 hours of a sensitising event

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Notes

• Early pregnancy bleeding affects 20–40% of pregnant women, with miscarriage and ectopic pregnancy being the most common causes

• The discriminatory zone for hCG (typically 1500–2000 IU/L) is useful; absence of an intrauterine gestational sac above this level strongly suggests ectopic pregnancy

• A pregnancy of unknown location necessitates close follow-up with repeat hCG measurements and ultrasound examinations

• All women of reproductive age presenting with abdominal pain should be presumed to have an ectopic pregnancy until proven otherwise

• Early pregnancy assessment units facilitate prompt, accurate diagnosis and management, reducing unnecessary admissions and improving patient outcomes