Molar Pregnancy

Molar pregnancies are uncommon problems that can occur during pregnancy. They happen when cells called trophoblasts grow abnormally. Trophoblasts are special cells that usually develop into the placenta, the organ that gives a growing baby nourishment.

There are two main types of molar pregnancies: complete and partial. In a complete molar pregnancy, the placenta grows abnormally, forming fluid-filled sacs. Importantly, there's no developing baby (fetus) in this type.

A partial molar pregnancy is different. In this case, the placenta might have a mix of normal and abnormal tissue. Sometimes, a small baby (fetus) might develop, but it's almost always too weak to survive. This usually means the baby will be lost (miscarried) early in the pregnancy.

Molar pregnancies can be risky, and in rare cases, they can lead to cancer. Early diagnosis and treatment are crucial for a good outcome.

In a molar pregnancy, the placenta, which is the organ that nourishes the developing baby, doesn't grow normally. Instead of forming as it should, it often looks like a cluster of cysts. This abnormal growth means the baby either doesn't develop at all, or develops in a way that isn't healthy and can't survive.

At first, a molar pregnancy might seem like a typical pregnancy. However, most molar pregnancies show signs that differ from a healthy pregnancy. Early warning signs, often appearing in the first three months of pregnancy, include:

• Vaginal bleeding: Bleeding from the vagina, ranging in color from dark brown to bright red, can be a key symptom.
• Severe morning sickness: Extreme nausea and vomiting are common.
• Vaginal discharge: Sometimes, grape-like cysts can be passed through the vagina.

Thanks to better ways of checking for pregnancies, doctors often find molar pregnancies during the first three months. If the condition isn't spotted early, other symptoms can appear, which might also be mistaken for other issues. These later signs might include:

• Rapid uterine growth: The uterus (womb) grows much faster than expected, and may feel unusually large for the stage of the pregnancy.
• Ovarian cysts: Cysts can develop on the ovaries.
• Hyperthyroidism (overactive thyroid): The thyroid gland, which regulates many bodily functions, can become overactive.

This overactivity can cause various symptoms, like nervousness, difficulty sleeping, and even weight loss. It's important to remember that these symptoms can also be caused by other conditions, so it's crucial to see a doctor for any concerns about pregnancy.

Molar pregnancies happen when a fertilized egg develops abnormally. Normally, a human cell has 23 pairs of chromosomes. Each pair has one chromosome from the mother and one from the father.

In a complete molar pregnancy, something goes wrong with the egg's chromosomes. Instead of getting one set of chromosomes from the mother and one from the father, the mother's chromosomes are missing or don't work properly. The father's chromosomes are duplicated, meaning there's an extra set. This happens when one or two sperm fertilize the egg.

In a partial or incomplete molar pregnancy, the mother's chromosomes are present, but the father contributes two sets of chromosomes. This leads to an extra set of chromosomes, giving the developing embryo 69 chromosomes instead of the usual 46. This is most often caused by two sperm fertilizing the egg, resulting in extra copies of the father's genes.

Molar pregnancies, where the pregnancy develops abnormally, can be influenced by several factors.

One significant factor is a history of previous molar pregnancies. If you've had a molar pregnancy before, you have a slightly increased chance of having another. This happens in about 1 out of every 100 people who've had a molar pregnancy. This means the risk is still relatively low, but it's important to be aware of this possibility.

Another factor is the mother's age. Molar pregnancies are more common in women older than 43 or younger than 15. This might be because the developing fetus is more likely to have chromosomal abnormalities at these ages, which can contribute to the abnormal growth associated with molar pregnancies.

Sometimes, after a molar pregnancy is treated, some molar tissue remains and keeps growing. This is called persistent gestational trophoblastic neoplasia (GTN). It's more common after a complete molar pregnancy than after a partial one.

A key sign of GTN is a high level of a pregnancy hormone called human chorionic gonadotropin (hCG) in the blood, even after the molar pregnancy is gone. This hormone is made by the developing placenta, and too much of it after the pregnancy ends can be a sign that something isn't right. In some cases, the abnormal tissue that causes the molar pregnancy can grow deeply into the uterine wall. This can lead to vaginal bleeding.

Doctors typically treat persistent GTN with chemotherapy. In some situations, a hysterectomy (removal of the uterus) might be necessary.

Very rarely, a more serious type of GTN called choriocarcinoma can develop. This is a cancer that can spread to other parts of the body. While this is serious, choriocarcinoma is often treated successfully with chemotherapy. This type of cancer is more likely to occur after a complete molar pregnancy than after a partial one.

If you've experienced a molar pregnancy, it's crucial to talk to your doctor or midwife before trying to conceive again. A good rule of thumb is to wait at least six months, and possibly up to a year, before trying to get pregnant again. While the chances of having another molar pregnancy are generally low, having one before increases your risk.

In future pregnancies, your healthcare provider will likely schedule more frequent ultrasounds early on. These ultrasounds will help monitor your pregnancy and ensure the baby is growing and developing normally.

A transvaginal ultrasound uses a special wand (a transducer) inserted into the vagina. You lie on your back on an exam table. The wand sends sound waves that create pictures of your pelvic organs. Doctors use these pictures to look for problems.

If a doctor suspects a molar pregnancy, they'll likely order blood tests and a transvaginal ultrasound. This type of ultrasound is often used early in pregnancy.

A complete molar pregnancy might show certain things on an ultrasound as early as eight or nine weeks of pregnancy. These might include:

• No baby (embryo or fetus): The ultrasound won't show a developing baby.
• No amniotic fluid: The fluid that surrounds and protects the baby is absent.
• A large, filled-up placenta: The placenta, the organ that provides nutrients to the baby, is unusually large and fills most of the uterus.
• Ovarian cysts: Fluid-filled sacs might be present on the ovaries.

A partial molar pregnancy might show some different things on an ultrasound:

• Small baby: The baby might be smaller than expected for the stage of pregnancy.
• Low amniotic fluid: Again, the fluid surrounding the baby is likely to be less than normal.
• Unusual placenta: The placenta might look different than normal.

After finding a molar pregnancy, the doctor might also check for other possible problems, such as:

• Preeclampsia: This is a serious condition involving high blood pressure.
• Hyperthyroidism: This is a condition where the thyroid gland is overactive.
• Anemia: This is a condition where the blood doesn't have enough red blood cells.

It's important to remember that these are just potential findings. The doctor will use the ultrasound results, along with other tests, to make a diagnosis and determine the best course of treatment.