Molar Pregnancy

• Consider in any early pregnancy with:
  • Disproportionately large uterus for gestational age, or
  • Very high β-hCG, severe hyperemesis, early-onset hypertension, or thyroid symptoms.
• Stabilise if bleeding or haemodynamically compromised.
• Arrange urgent gynae assessment for uterine evacuation and follow-up planning.

• Complete hydatidiform mole (CHM):
  • Usually 46,XX paternal-only genetic material (empty ovum fertilised and duplicated).
  • No fetus; diffuse hydropic swelling of chorionic villi with marked trophoblastic proliferation.
  • Higher risk of progression to gestational trophoblastic neoplasia (GTN).
• Partial hydatidiform mole (PHM):
  • Triploid conceptus (e.g. 69,XXX/XXY) due to fertilisation of a normal ovum by two sperm.
  • Abnormal placenta with some normal villi; may have some fetal tissue or sac present.
  • Lower but still present risk of GTN.
• Risk factors include extremes of maternal age (very young or > 35–40 years) and previous molar pregnancy.

• Vaginal bleeding in the first or early second trimester (often painless but may be heavy or recurrent).
• Excessive nausea and vomiting (hyperemesis gravidarum) due to very high β-hCG.
• Uterus larger than dates, pelvic pressure or discomfort.
• Absence of fetal heart tones when they should be expected.
• Passage of vesicular tissue per vagina (grape-like clusters) – classic but not always seen.
• Early-onset pre-eclampsia (before 20 weeks) – strongly consider molar pregnancy.
• Shortness of breath or respiratory distress if trophoblastic emboli or pulmonary oedema occur (rare but serious).

• β-hCG: often markedly elevated for gestational age; may be >100,000 IU/L.
• Ultrasound:
  • Classic appearance for complete mole: “snowstorm” or “cluster of grapes” – diffuse echogenic mass with multiple small cystic spaces, no fetus.
  • Partial mole: may show abnormal placenta with cystic spaces and a growth-restricted or abnormal fetus.
  • Ovarian theca lutein cysts may be seen (due to high β-hCG) and can be large or bilateral.
• Baseline bloods:
  • FBC (anaemia, infection).
  • U&E and LFTs.
  • Clotting profile if heavy bleeding.
• Rh status and group & save/crossmatch if bleeding significantly or evacuation anticipated.
• Definitive diagnosis is by histopathological examination of evacuated tissue.

• Heavy uterine bleeding ± haemodynamic compromise.
• Early pre-eclampsia, hyperthyroidism, and high-output cardiac strain (due to very high β-hCG levels).
• Respiratory compromise from trophoblastic embolisation or pulmonary oedema.
• Progression to gestational trophoblastic neoplasia (GTN), including:
  • Invasive mole (locally invasive).
  • Choriocarcinoma (highly malignant, can metastasise early, especially to lungs and brain).

• Assess ABC; treat shock if present:
  • Secure IV access, take bloods (including group & save/crossmatch).
  • Start IV fluids cautiously; transfuse if needed as per local protocol.
• Control heavy vaginal bleeding with uterine massage and urgent obstetric review.
• Check vitals repeatedly; monitor for hypoxia or respiratory distress.
• Administer antiemetics for severe nausea/vomiting.
• Analgesia as required (paracetamol ± opioids as appropriate).
• Arrange urgent gynae admission or review for:
  • Planned uterine evacuation (suction curettage/D&C) in a controlled theatre environment.
  • Baseline staging and planning of follow-up.
• Anti-D immunoglobulin if indicated for Rhesus-negative patients with bleeding or planned uterine instrumentation (follow local policy).

• Serial quantitative β-hCG levels (e.g. weekly until normal, then monthly for a defined period – as per local GTD protocol).
• Failure of β-hCG to fall appropriately, plateauing, or secondary rise suggests GTN → oncology/GTD centre referral.
• Treatment for GTN may include chemotherapy (often highly effective), rarely surgery or radiotherapy.
• Contraception:
  • Effective contraception is recommended during follow-up to avoid confusing new pregnancy with GTN recurrence.
  • Hormonal methods are generally acceptable once β-hCG is falling; check local guidance.

• Explain that a molar pregnancy is an abnormal pregnancy where the placenta tissue has grown abnormally and cannot result in a viable baby.
• Reassure that:
  • Most women do well with appropriate treatment and follow-up.
  • Future normal pregnancies are often possible once surveillance is complete.
• Stress the importance of:
  • Attending all follow-up appointments for β-hCG monitoring.
  • Using reliable contraception until the team confirms it is safe to conceive again.
• Acknowledge the emotional impact of pregnancy loss and the anxiety about malignancy; offer psychological support where available.

• Obstetricians/gynaecologists – diagnosis, evacuation, and initial follow-up.
• Pathologists – confirm type of mole and assess risk features.
• Oncology or GTD specialist centre – manage GTN if it develops.
• Primary care / family planning – assist with contraception and long-term support.

For juniors in ED, a clear handover to gynae and accurate documentation of findings, β-hCG, and ultrasound impressions are key safety steps.