2.3 Molar pregnancy (hydatidiform mole)


Pathological pregnancy due to cystic degeneration of the placenta (abnormal proliferation of the chorionic villi). The mole presents in the form of translucent vesicles, 1 to 2 cm in diameter, connected by filaments like a cluster of grapes. In most cases there is neither foetus nor amniotic sac.

2.3.1 Diagnosis

Signs and symptoms

– Spontaneous bleeding of variable severity.
– Uterus larger and softer than expected for gestational age.
– No foetal heart tone, movements, or poles at five months.
– Nausea and vomiting that is more frequent and lasts longer than in a normal pregnancy.
Occasionally:
– Oedema, proteinuria, or hypertension if the pregnancy is advanced;
– Enlarged ovaries, weight loss, mild jaundice;
– Slow, fragmentary, incomplete abortion, occasionally accompanied by heavy bleeding with expulsion of vesicles.

Additional investigations

– The pregnancy test is always positive.
– Ultrasound shows a heterogeneous, vesicular placenta filling the entire uterine cavity.

2.3.2 Management

– Refer to a CEmONC facility: risk of bleeding and complicated uterine evacuation.
– Insert an IV line (16-18G catheter) and administer Ringer lactate.
– Closely monitor: heart rate, blood pressure and bleeding.
– Prepare for a possible transfusion, determine the patient’s blood type, select potential donors or ensure that blood is available. If transfusion is necessary, only use blood that has been screened (HIV-1, HIV-2, hepatitis B, hepatitis C, syphilis, and malaria in endemic areas).
– Evacuate the mole using aspiration, or if not available, digital curettage or careful instrumental curettage (Chapter 9). The evacuation should be done under oxytocin, 20 IU in 1 litre of Ringer lactate or 0.9% sodium chloride administered over 2 hours (160 drops/minute) to prevent bleeding and reduce the risk of perforation (the uterine wall is thin and weakened). No debris should remain after uterine evacuation. If possible, perform an ultrasound to make sure the uterus is empty.
Provide effective contraception for at least one year, or perform tubal ligation if desired.

2.3.3 Follow-up

In approximately 10 to 15% of patients, the mole develops into persistent trophoblastic disease or choriocarcinoma.

Two weeks after the evacuation, perform an ultrasound if possible to be sure the uterus is empty. If ultrasound is not available and bleeding persists, consider a second aspiration (even when done correctly, retention of molar debris is not uncommon).

Eight weeks after the evacuation, perform the first follow-up pregnancy test. The test does not become negative immediately after the evacuation, but it should be negative within 8 weeks.
• If the test is negative, perform a pregnancy test every 4 to 8 weeks for 1 year.
• If the test is positive after 8 weeks or becomes positive during subsequent follow-up despite effective contraception, refer the patient to rule out or treat persistent trophoblastic disease or choriocarcinoma.