Information for Patients with Molar Pregnancies or Choriocarcinoma
Follow-up after a molar pregnancy
Once patients have been registered with the follow-up centre the hCG level will be checked every 2 weeks to see if the level is falling or not. At the Charing Cross centre the measurements are initially performed on both blood and urine tests. You will be sent a kit that allows the samples to be posted back to us. The kit contains full details of when the blood and urine tests should be taken and how the sample should be handled prior to posting.
The results are available 1-2 days after the sample is received. At Charing Cross the pattern of results for each molar pregnancy patient is analysed and you can check your results and any treatment plans by ringing in.
The graphs above in Fig 5 show two examples of the blood hCG levels in women after a molar pregnancy. In the first the levels fall quite quickly reaching normal after 4 weeks, whilst in the second the levels fall more slowly taking 4 months to reach normal. Generally the length of time taken to get back to normal is less than 8 weeks; however some patients have an elevated but falling hCG level for up to 6 months and do not require any additional treatment (approximately 50%).
In the patients where the hCG level falls to normal the tests change to being only urine tests. The duration of monitoring varies depending on the type of molar pregnancy and when the hCG levels reach normal.
For complete hydatidiform mole patients, if the hCG level gets to normal within the 56 days of the evacuation then the monitoring continues for a total of 6 months from the day of the evacuation. In those patients where the hCG level takes more than 56 days to get to normal the monitoring goes on for 6 months from the date of the first normal sample.
For partial hydatidiform mole patients, following confirmation on review at Charing Cross, follow up begins with serum and urine every two weeks until hCG levels are normal. This is followed by one confirmatory normal urine sample after 4 weeks.
In both situations it is advised that a further pregnancy is deferred until the end of the follow-up period, as a new pregnancy may mask the evidence of the relapse of the illness that can happen in a very small number of women.
The risk of developing a future second molar pregnancy is quite small, we would estimate it at approximately a 1 in 100 risk. Even more unusually the surge of hormones in a later pregnancy can cause a relapse of the old molar pregnancy and start any cells still present to grow again and potentially cause problems. Whilst this problem is very rare, we screen for it by testing the urine 6 weeks after delivery and the blood and urine 4 weeks later after this.