The presentation of PCM in patients under the age of 40 years old is rare, and more so within pregnancy. There have been 162 4–17
cases of myeloma in pregnancy, 92 4–10
of which were diagnosed while the women were pregnant.
Using OVID (http://www.ovid.com
), we conducted a Medline search restricted to the English language and with the key words ‘Multiple Myeloma’ and ‘Pregnancy’. A total of 17 papers were retrieved.
Of the 16 pregnant women, 7 had been diagnosed and given treatment before becoming pregnant. Of the women diagnosed in pregnancy the presentation was either due to development of bony pain or made due to identification of a biochemical abnormality. Three of the nine patients diagnosed as having PCM in pregnancy had bone pain. Two described spinal cord compression2 4
and the other a pathological fracture of the neck of humerus.6
Of the other six patients, one was diagnosed at 15 weeks after being admitted for hyperemesis. On admission she was found to be anaemic, in renal failure and hypercalcaemic. This pregnancy was terminated at 19 weeks to enable treatment to begin.5
The other cases describe women that were anaemic but generally well and on further investigation were found to have PCM.
The literature search also revealed a paper that describes a woman, known to have PCM, having repeated positive pregnancy tests despite not being pregnant. The article described that through immunohistological stains it was revealed that the myeloma cells expressed immunoactive human chorionic gonadotrophin (hCG) and therefore PCM can cause positive pregnancy test results in a non-gravid woman.18
Throughout the pregnancy, fetal growth and development has been described as normal provided maternal health was maintained. Of the patients already diagnosed as having PCM and on treatment at time on conception, there were no fetal abnormalities described. The majority of cases were allowed to deliver at term by normal vaginal delivery. One case, as previously described, underwent a termination at 19 weeks, and one pregnancy was delivered at 34 weeks by caesarean section due to disease progression (multiple lytic lesions) and the need to start treatment urgently.
One of the cardinal signs of PCM is proteinuria. This, in regards to pregnancy, is a risk factor and sign of pre-eclampsia. There are no reports in the literature first of the risk to a patient with PCM developing pre-eclampsia or second, how it would be diagnosed and treated. Due to the known connection of pre-eclampsia with renal impairment, regular blood pressure readings were performed. In this case enoxaparin was given due to the risk of thromboembolism, due to the known prothrombotic nature of PCM.
Tavani et al
performed a case-control study in 1997 assessing reproductive factors and the risks of developing lymphoma and myeloma. The study concluded that the immunological changes that occur in early pregnancy are likely mechanisms for the protection of patients from the risk of developing Hodgkin's lymphoma but did not protect against PCM or non-Hodgkin's lymphoma.19
In the postpartum period complications of PCM appeared in the women, but all of the neonates appeared to do well. The papers describe that the monoclonal band produced by the mother with PCM freely crosses the placenta with one report noting concentrations of 2000 mg/litre in the cord blood of the fetus; however this does not appear to have an adverse effect on the fetus. Follow-up to 28 months of the baby revealed no problems and chromosomal studies of the cord blood revealed a normal karotype of the baby.14
One case report observed that a neonate, delivered by uncomplicated, planned caesarean section at 34 weeks for maternal reasons, had seizures that were due to abnormal calcium regulation. The neonate's urine had no abnormal proteins, and serum protein electrophoresis revealed negative findings. After discharge on day 10 of life the baby had no further fits or complications.6
Although several pregnancies were conceived while being treated for PCM, including cyclophosphamide,14
and α-interferon treatment,12
no fetal abnormalities are reported. One case was delivered early, as was our case, due to disease progression and the urgent need to begin treatment. The postpartum complications of PCM described that lead to death are renal failure, haemorrhage and sepsis. One woman who was described as having monoclonal gammopathy of undetermined significance (MGUS). The pregnancy was uneventful, but trace amounts of Bence Jones protein were detected. This was put down to progression of MGUS rather than PCM. In the postnatal period the patient progressed to PCM with lethargy and bone pain. The woman was admitted once renal failure was detected and she became profoundly septic. A CT scan revealed extradural plasmacytoma, which eventually caused an intracranial haemorrhage.11
Another case describes a woman being admitted post partum due to recurrent rib fractures and haemorrhage requiring blood transfusions. The patient died soon after.17
- Plasma cell myeloma (PCM) is an incurable disease with an estimated median survival of 5 years for the mother.
- It is rare in patients under 40 years old, but with an increasing maternal age it is likely that the incidence of diagnosis within pregnancy will increase.
- PCM within pregnancy appears to have little effect on the fetus as long as maternal well-being is maintained.