A molar pregnancy is a rare complication in which abnormal tissue grows in the uterus instead of a healthy pregnancy. It is also called a hydatidiform mole and cannot develop into a baby.
Doctors describe two types. A complete molar pregnancy has abnormal cells growing in the uterus and no sign of a baby. A partial molar pregnancy may show early signs of a baby, but it cannot fully develop or survive. A molar pregnancy happens by chance and is not caused by anything either parent did.
Some people have no symptoms, and the condition is found at an early ultrasound scan or after a miscarriage. Possible signs include vaginal bleeding or dark discharge, severe sickness, and a bump that seems larger than expected. Anyone with these symptoms in pregnancy should contact a midwife or doctor.
A molar pregnancy may end on its own. If it does not, a procedure to remove the tissue is usually needed, sometimes medicine. Afterwards, regular blood and urine tests check that the pregnancy hormone hCG returns to normal, because in rare cases abnormal cells can remain and need further treatment.
Recovery can take time, both physically and emotionally. The specialist team can explain the follow-up plan and point to support services, and pregnancy loss charities offer information and someone to talk to. Time off and flexibility for follow-up tests can make the months after treatment easier.
Sources: NHS, MedlinePlus.