From the Guidelines
A molar pregnancy is an abnormal growth of tissue in the uterus that develops instead of a normal pregnancy, occurring when there are problems with fertilization, resulting in abnormal development of placental tissue, and is considered a premalignant disease. This condition is also known as gestational trophoblastic disease (GTD) and can be benign or malignant. The most common form of GTD is hydatidiform mole (HM), also known as molar pregnancy, which encompasses about 80% of all GTD cases 1.
Types of Molar Pregnancy
There are two main types of molar pregnancies: complete and partial. Complete molar pregnancies occur when no fetal tissue develops, while partial molar pregnancies occur when some abnormal fetal tissue may be present. Symptoms of molar pregnancy typically include vaginal bleeding, severe nausea and vomiting, high blood pressure, and the uterus growing larger than expected.
Diagnosis and Treatment
Diagnosis of molar pregnancy is often made based on ultrasound findings in combination with clinical symptoms and human chorionic gonadotropin (hCG) levels 1. Treatment usually involves surgical removal of the abnormal tissue through a procedure called dilation and curettage (D&C). After removal, patients need regular blood tests to monitor hCG levels for 6-12 months to ensure all molar tissue is gone and hasn't developed into a more serious condition called gestational trophoblastic neoplasia (GTN) 1.
Monitoring and Follow-up
Monitoring of hCG levels is crucial because approximately 15-20% of complete molar pregnancies and 1-5% of partial molar pregnancies can develop into GTN, a potentially cancerous condition 1. Patients are typically advised to avoid pregnancy during the monitoring period to prevent confusion in hCG level interpretation. The NCCN Panel recommends workup of patients with HM to include history and physical, pelvic ultrasound, quantitative hCG assay, complete blood count with platelets, liver, renal, and thyroid function tests, and blood type and screen 1.
Key Points
- Molar pregnancy is an abnormal growth of tissue in the uterus that develops instead of a normal pregnancy.
- There are two main types: complete and partial molar pregnancies.
- Symptoms include vaginal bleeding, severe nausea and vomiting, high blood pressure, and the uterus growing larger than expected.
- Treatment involves surgical removal of the abnormal tissue through D&C.
- Regular blood tests to monitor hCG levels for 6-12 months are necessary to ensure all molar tissue is gone and hasn't developed into GTN.
- Patients should avoid pregnancy during the monitoring period to prevent confusion in hCG level interpretation.
From the Research
Definition of Molar Pregnancy
- A molar pregnancy, also known as gestational trophoblastic disease, is a type of abnormal pregnancy where a non-viable fertilized egg implants in the uterus and will fail to come to term 2, 3, 4.
- It is characterized by the abnormal proliferation of trophoblast cells, which can range from benign to malignant 2, 3, 5, 6.
Types of Molar Pregnancy
- Molar pregnancy can be categorized as complete or partial, based on gross and microscopic histopathologic and karyotypic findings 2.
- Complete moles have a characteristic appearance of a "bunch of grapes" and are usually diploid, while partial moles have a mixture of normal and abnormal cells and are usually triploid 4.
Diagnosis and Management
- Early detection of molar pregnancy is crucial, and ultrasound plays a central role in the diagnosis 3.
- After uterine evacuation, serial human chorionic gonadotropin (hCG) levels are evaluated to detect persistent gestational trophoblastic tumor (GTT) 2, 5.
- Treatment for molar pregnancy depends on the type and stage of the disease, and may include chemotherapy, surgery, or a combination of both 2, 5, 6.
Complications and Outcomes
- Molar pregnancy can lead to serious complications, such as persistent GTT, gestational trophoblastic neoplasia (GTN), and metastatic disease 2, 3, 5, 6.
- With proper management, the prognosis for molar pregnancy is generally good, and most women can expect normal reproductive functioning after treatment 2, 6.