How should I approach the initial investigation and confirmation of a suspected molar pregnancy in primary care?

In primary care, the initial approach to a suspected molar pregnancy primarily involves recognising potential indicators and promptly referring the woman for specialist assessment, as direct confirmation typically occurs in secondary care settings like an Early Pregnancy Assessment Service (EPAU) ¹,²,⁴.

Key considerations for initial investigation and referral:

• Positive Pregnancy Test After 3 Weeks: Be aware that a positive urine pregnancy test taken 3 weeks after a previous pregnancy event (e.g., miscarriage or delivery) should prompt a review to rule out a retained pregnancy, molar pregnancy, or ectopic pregnancy, and to assess the need for further investigations or treatment ¹,⁴.
• Clinical Symptoms and Signs: For women presenting with bleeding or other symptoms and signs of early pregnancy complications, a referral to an EPAU or out-of-hours gynaecology service is necessary if they experience pain, have a pregnancy of 6 weeks' gestation or more, or have a pregnancy of uncertain gestation ¹,²,⁴. The urgency of this referral depends on the clinical situation ¹,²,⁴.
• Immediate Referral for Acute Symptoms: Arrange immediate hospital admission if the woman shows signs of haemodynamic instability (such as pallor, tachycardia, tachypnoea, hypotension, shock, or collapse), or if there is significant concern about the degree of bleeding or pain ²,⁴. Immediate admission to an EPAU or out-of-hours gynaecology service is also required for women with a positive pregnancy test who, on examination, have abdominal pain and tenderness, pelvic tenderness, or cervical motion tenderness ²,⁴.
• Role of hCG Measurements: While serum human chorionic gonadotrophin (hCG) measurements are used in secondary care for assessing trophoblastic proliferation and determining subsequent management of a pregnancy of unknown location, they should not be used in primary care to determine the location of the pregnancy ¹. Clinical symptoms are considered more important than serum hCG results in a pregnancy of unknown location ¹. If serial hCG measurements are taken (typically 48 hours apart), their interpretation guides further management, such as offering a transvaginal ultrasound scan or referral for clinical review ¹.
• Information and Support: For all women referred to an EPAU or out-of-hours gynaecology service, explain the reasons for the referral and what she can expect upon arrival ¹,²,⁴. Provide written information about what to do if symptoms worsen, including how to access emergency care 24 hours a day ¹,⁴.

Upon referral to an EPAU, a transvaginal ultrasound scan is typically offered to identify the location of the pregnancy and whether there is a fetal pole and heartbeat, which is crucial for confirming the diagnosis of a molar pregnancy or other early pregnancy complications ¹,²,⁴.