Molar Pregnancy

Molar pregnancy, also known as hydatidiform mole, is an uncommon pregnancy complication. It is typically the abnormal growth or development of trophoblasts (the cells that usually develop into the placenta).

Molar pregnancy is of two types, which include partial molar pregnancy and complete molar pregnancy. A partial molar is characterized by a normal placental tissue alongside an abnormally developing placental tissue.

Development of the fetal tissues occurs, but it usually leads to an early miscarriage because the fetus cannot survive. The complete molar is characterized by an abnormal placental tissue that’s swollen and seemingly forming cysts with fluid. It prevents the development of fetal tissue.

Molar pregnancy is imbued with grave complications, which include a highly uncommon form of cancer. It requires early diagnosis and treatment. In the course of a healthy pregnancy, the placenta develops inside the uterus. It feeds the baby via the umbilical cord.

However, in molar pregnancy, the uterine tissue becomes an abnormal mass or tumor rather than a placenta. This pregnancy complication can trigger health complications for the mom as well in severe cases.

Indications of molar pregnancy

It looks like a normal pregnancy, but then almost all molar pregnancies come with certain indications. They include the following:

  • During the first three months, the vaginal bleeding ranges from bright red to dark brown
  • An intense feeling of nausea and vomiting
  • From time to time, cysts looking like grapes coming out from the vagina
  • An unpleasant sensation in the pelvic region
  • Fertility or conception problems
  • Previous loss of pregnancy

Your doctor or pregnancy care consultant or provider should be the first port of call if you notice any indication(s) of molar pregnancy. Your doctor will likely notice other signs that you missed.

Other symptoms of molar pregnancy that your doctor may notice includes:

  • The rapid development of the uterine region; the uterus becomes too big for that stage of pregnancy
  • High blood pressure
  • Preeclampsia — a condition that triggers high blood pressure and the presence of protein in the urine after about five months of pregnancy
  • Ovarian cysts
  • Anemia (triggered by a low level of iron)
  • Overactive thyroid (hyperthyroidism)

Causes of molar pregnancy

No one can control the occurrence of molar pregnancy. Any particular activity does not trigger it, and it can happen to women of all ethnicities, ages, and backgrounds. Sometimes, it occurs because of a mix-up at the genetic (DNA) level.

Almost all women carry hundreds of thousands of eggs. Some of these eggs may not develop properly. They’re usually assimilated by the body and put out of commission or rendered dormant. A molar pregnancy can be triggered by an egg that was abnormally fertilized. Human cells usually carry 23 pairs of chromosomes.

A chromosome in every pair comes from the father while the other comes from the mother. In a complete molar pregnancy, fertilization occurs when one or two sperm makes contact with an empty egg. The entirety of the genetic information is inherited from the father.

Risk factors of molar pregnancy

These are pre-existing conditions that can make a person prone or more likely to have a molar pregnancy. Molar pregnancy is not common, and its occurrence rate is 0.1 percent.  This means it happens in roughly 1 out of 1000 pregnancies.

The different risk factors affiliated with molar pregnancy include:

  • Maternal age: A molar pregnancy has a greater chance of manifesting in females above 35 and below 20.
  • The previous occurrence of molar pregnancy: If you have experienced at least one molar pregnancy incident, you’re more likely to have a recurrence. A recurring molar pregnancy takes place in approximately 1 out of every 100 females.

Complications associated with molar pregnancy

After removing a molar pregnancy, the molar tissue may still be present and continue to develop. This situation is referred to as persistent gestational trophoblastic neoplasia (GTN).

This situation happens in an estimated 15 to 20 percent of complete molar pregnancies and approximately 5 percent of partial molar pregnancies.

An indication of persistent GTN is a strong presence of human chorionic gonadotropin (HCG). This is a pregnancy hormone that still exists after the molar pregnancy has been removed. In many instances, an intruding hydatidiform mole permeates deep into the uterine wall’s middle layer, triggering vaginal bleeding.

Occasionally, a cancerous type of GTN  called choriocarcinoma grows and spreads to other organs. Choriocarcinoma is usually treated with several cancer drugs, which yields successful results. 

It is imperative to know that a complete molar pregnancy is more prone to this complication than a partial molar pregnancy.

How to prevent molar pregnancy

If you’ve experienced molar pregnancy before, you must talk to your doctor or pregnancy care provider before conception.

The doctor may advise waiting for a period ranging from six months to one year before becoming pregnant. Although the risk of molar pregnancy recurring is low, it is higher than the risk for females with no molar pregnancy experience.

During any more pregnancies, your doctor or care provider may carry out ultrasounds in the early stages. This is to watch your condition and offer an assurance of normal pregnancy development. They may also discuss genetic testing in the prenatal stage.

A pelvis ultrasound of a molar pregnancy will usually show a grape-like, closely-packed bunch of blood vessels and tissue. Your doctor may also recommend other imaging technologies like MRI and CT scans to verify the diagnosis.

The surest or best way to avoid a molar pregnancy situation is not to get pregnant at all.

Treatment options for molecular pregnancy

Dilation & Curettage

Your doctor may opt for a treatment procedure known as dilation and curettage (D&C), and most times, this is the treatment used for pregnancy loss. While this procedure is ongoing, the doctor opens your cervix with special tools.

Then he takes out the molar tissue from your uterus. This is the best treatment option for you if you want to get pregnant again. After a D&C, your doctor will carry out multiple blood tests over the next few months. They will check to see whether your HCG levels are getting back to normal.


Persistent GTN can virtually always be treated successfully, especially with the use of chemotherapy.


An alternative treatment method is the removal of the uterus itself (hysterectomy). This treatment option will not only prevent a future occurrence of molar pregnancy but also prevent normal pregnancy too.

It should be opted for as a last option. You will be induced into a full state of unconsciousness for the duration of this procedure. A hysterectomy is an uncommon treatment for a molar pregnancy.


If your blood is Rh-negative, you will receive a drug called RhoGAM as part of your treatment procedure. This inhibits some complications affiliated with growing antibodies. Verify and inform your doctor if you have: A-, O-, B-, or AB- blood types.


After the removal of your molar pregnancy, you will require further blood tests and monitoring. You must ensure no remnant molar tissue was left behind in your womb. In uncommon cases, molar tissue can redevelop and trigger some types of cancers.

Your doctor will monitor your hCG levels and schedule periodic scans for up to a year after treatment.