Hydatidiform Mole - Molar pregnancy

- a personal account by Mum2Joshua

In 2002 I had a molar pregnancy. I discovered I was pregnant after I was admitted to hospital with severe abdominal pain and chronic sickness. An emergency scan showed that everything seemed normal and I was in the very early stages of pregnancy, just 3 weeks pregnant and yet I was showing signs of being nearer 7-8 weeks pregnant. I had a follow up scan weeks later, and although the pain had gone I was still very sick, unable to keep any solid food down. The scan showed that everything seemed ok and I was given advice on helping with the extreme sickness. By the time I was 7 weeks+ I was struggling to hold fluids down and I became very weak and tired. My doctor prescribed me some medication to help with the sickness, which seemed to help a little bit, enough to prevent me becoming dehydrated. At 9 weeks all my sickness vanished, but my doctor reassured me that it was normal and I should enjoy my sick free pregnancy.

I went for my routine 12 week scan, but the news was not good. The sonographer called in a doctor, who confirmed that they could not find a heart beat, and I was measuring at 9 weeks. I was told I had had a missed miscarriage, and the only explanation I was offered was, these things sometimes just happen. I needed a D&C as I showed no sign of bleeding.

A couple of weeks later I received a letter from my doctor stating that there were signs of abnormalities and I should make an appointment to see him straight away. This is when I was first told I had had a molar pregnancy, but my doctor was unable to give me any details. He said it was very rare, and then attempted to share his understanding of the condition to me, which turned out to be very wrong. I saw my consultant in my home town, who said I needed referring to a specialist centre in Sheffield and that they would explain more about the condition to me. I still did not receive any information or understanding about what had happened. At this stage all I had understood is possible infertility, and risk of cancer. It became a very scary time for me and my family.

I quickly heard from the specialist centre, and I was sent a lot of leaflets and telephone numbers. Everything seemed so contradicting to what I had already been told. I rang the centre and spoke to one of the nurses who talked to me for a long time and was very supportive. For the first time things were explained to me in a way that I understood, and they no longer seemed so scary.

I was told that a molar pregnancy occurs when there is a complication of the paternal chromosomes. A normal pregnancy has 23 maternal chromosomes, and 23 paternal chromosomes. In a molar pregnancy there are double the number of paternal chromosomes, this could be due to it duplicating or 2 sperms fertilising the same egg. A molar pregnancy comes in 2 forms. A complete mole is where the paternal chromosomes have duplicated but there are no maternal chromosomes. This basically means the egg was empty. In this case there is no placenta, sac or embryo. It forms as a cluster of cells and is detected by an ultrasound scan. It appears like a bunch of grapes in the uterus. The second form is a partial mole, the more common of the two. This is where the egg is normal, but the paternal chromosomes are duplicated. The pregnancy seems to progress as normal, the placenta forms as does the sac. It is also possible for the embryo to start to form, but part of the placenta forms clusters of molar cells. The forming embryo has no chance of survival, from the moment of fertilisation it has too many chromosomes, and the miscarriage usually occurs within the first 12 weeks. It is not always possible to detect a partial mole by ultrasound alone.

Molar pregnancies are rare, affecting about 1 in 1500 pregnancies in the UK. They usually require no treatment at all, although screening of the pregnancy hormone hCG is required afterwards to ensure that the levels return to normal. A molar pregnancy results in higher levels of this hormone, and this is thought to be the reason why the levels of sickness is increased, as well as having a bigger ‘bump’ for dates. The hormone levels usually return to normal soon after the D&C but in some cases it can take up to a year.

In very rare cases a molar pregnancy can begin to spread like a cancer, but it is not a cancer just persistent benign tumours left after the D&C (the hydatidiform mole or clusters of molar cells are benign tumours). This requires treatment, and sometimes a second D&C to remove any molar cells left in the uterus (15% of complete moles and 1% of partial moles). In even rarer cases of a complete molar pregnancy (1 in 30,000) these benign tumours can become cancerous but even then the treatment is very efficient and it is quickly identified due to the regular screening from the specialist centres.

Although it is recommended that you wait for 6 months to a year after having a molar pregnancy before trying for another baby, it is not thought to affect your long term fertility. There is only a 1-2% risk of having a second molar pregnancy, and this risk is reduced if it is a different father. Even if the molar pregnancy progresses into one of the rarer forms, there is no evidence to suggest that fertility is affected and it is very likely that you can go on to have perfectly healthy pregnancies once you have been given the all clear. Any pregnancies after the molar pregnancy are likely to be monitored for the short term by your specialist centre just to make sure the hormone levels return to normal.