Molar Pregnancy, Complete or Partial
What is a Molar Pregnancy?
Molar pregnancies are doubly sad for women. Not only do they lose their ‘baby’, depending on the type of molar pregnancy they have, they could be at increased risk of cancer.
With a molar pregnancy, women have all the signs and symptoms of normal pregnancy including nausea, breast tenderness and lack of periods.
The two types of molar pregnancies are:
1. Complete molar pregnancy
2. Partial molar pregnancy
A complete molar pregnancy, clinically known as an Hydatiform Mole, is when the fertilised egg contains only the father’s genetic material and none from the mother. There can be no human growth but instead the placental tissue goes berserk and duplicates itself over and over until the uterus is filled with its grape-like formation.
In a partial molar pregnancy, the egg gets fertilised by two sperm and the resulting embryo is incompatible with life, having 69 chromosomes, instead of the normal 46. Again the placental tissue is abnormal, and continues to grow even though there is every chance the foetus has died.
In very rare cases, there is another type of partial mole pregnancy, where a second normal fertilised egg is produced, but it gets consumed by the crazy growth of the abnormal placental tissue of its twin.
Diagram of an untreated molar pregnancy
Signs and Symptoms of a Molar Pregnancy (hydatiform mole)
Doctor may suspect a a molar pregnancy if
- · the woman’s uterus is large for her gestation period
- · she has severe vomiting in early pregnancy
- · she complains of passing of spots of bright red blood
- · she shows signs, symptoms, and has a positive blood test results for an over-active thyroid gland. (thyrotoxicosis). – Rare.
- · has no abdominal pain – unless her body is starting to abort the pregnancy
Generally around the 10th week of pregnancy, the woman may experience
- · bleeding which is dark brown in colour
- · severe nausea and vomiting
- · high blood pressure
- · abdominal cramps
Blood tests will reveal extremely high levels of the pregnancy hormone HCG(human chorionic gonadotrophin)in the case of a complete mole, and lower than normal levels in a partial mole. A uterine ultrasound scan will confirm the diagnosis.
Molar Pregnancy Informational Books
Molar Pregnancy Treatment
An immediate suction and curettage procedure must be carried out under general anaesthetic in a theatre, to rid the body completely of these cells.
It's very difficult to remove ALL of this tissue because it's nature is to embed deeply into the lining of the womb.
If the woman does not plan to have any more children, a complete hysterectomy may be recommended.
Left untreated, hydatiform moles can spread to other organs in the body. In a small percentage of these cases, they can turn cancerous (choriocarcinoma). Early treatment is vital and that includes complete removal of all cells and perhaps follow-up chemotherapy to kill off any remaining cells.
The woman then needs her blood levels of HCG monitored for up to a year afterwards, as high levels indicate that the cells have not been cleared and are still growing somewhere in her body. A woman who still has high levels of HCG in her body six months after the removal procedure is strongly advised to consider hysterectomy at this point, as she is likely to develop choriocarcinoma.
Follow-up observation is vital because even after the uterus is emptied of this tissue, about 20% of women with a complete molar pregnancy will find that the cells have continued to re-grow despite removal, and 2% of those with a partial molar pregnancy.
This is then called persistent gestational trophoblastic disease (GTD).
For this reason, it is strongly advised that women do not become pregnant again until given the all-clear by their doctors.
Ultrasound Scan of a Molar Pregnancy
Causes of Molar Pregnancies
The causes are not fully understood. Either the egg or the sperm may have been faulty, and a school of thought suggest they are caused entirely by a faulty sperm.
However, there does seem to be certain groups at higher risk of suffering one, and those are
- · Woman from Mexico, S Asia and the Philippines
- · Women over 40 years of age
- · Women who have previously suffered from a molar pregnancy
- · Women who have previously suffered more than one miscarriage
Chances of a future healthy pregnancy
Women who have suffered from a molar pregnancy have only a 1 or 2% chance of having another in the future, and most go on to give birth to healthy children.
The incidence of molar pregnancies in the general population is 1 : 1000, although for an unknown reason this figure is much higher in S Asia, the Philippines and Mexico where the incidence is 1 : 100.
Women who have suffered a molar pregnancy will be in need of grief counselling the same as women who have suffered a miscarriage or stillbirth. They will feel the loss acutely, and have the double blow of finding their health in danger with the risk of either developing cancer or having to have a hysterectomy, thus losing their chances of having children in the future.