There have been continuing improvements in the treatment of malignancies affecting children and young adults, and in the management of the reduced fertility that commonly follows such treatment. Thus, there are increasing numbers of women with treated (but not necessarily cured) malignant disease who become pregnant. In addition, malignant disease may occasionally present for the first time during pregnancy, and it may also be related to the pregnancy itself. Cancer prevalence rates in pregnancy are increasing (approximately 1 per 1000 pregnancies), primarily owing to older maternal age and the use of detection modalities that are now considered safe in pregnancy. The most common cancers seen are breast cancer, cervical cancer, haematological malignancies and melanoma.
Problems and special considerations
General problems of malignancy
These may be local (compression effects, local invasion, scarring, etc.), metastatic (liver involvement, etc.) or general (malaise, anaemia, endocrine effects, weight loss and cachexia). There may also be problems relating to treatment, such as side effects of cytotoxic drugs and steroids, and fibrotic effects of radiotherapy. There may be coagulation abnormalities or increased risk of deep-vein thrombosis necessitating anticoagulant therapy. Electrolyte disturbances (e.g. hypercalcaemia) may be a feature of the malignancy or its treatment.
Problems during pregnancy
Malignancies may be affected by the changing hormonal profile of pregnancy and its effects on the tissues; this may make certain tumours more aggressive (e.g. breast cancer, melanoma). Diagnoses may be delayed because of the overlap of symptoms with those of the pregnancy. Some maternal malignancies may metastasise to the fetus or placenta (e.g. melanoma), although in general this is rare. Women who have had childhood cancer may be at increased risk of complications in pregnancy, including gestational diabetes, hypertensive disorders and anaemia; an increased level of antenatal input may therefore be warranted.
The risks and benefits to the mother, the fetus and future fertility of administering or withholding treatment need careful consideration. The patient’s medication may need altering, especially in early pregnancy, since many cytotoxic drugs are harmful to the fetus; systemic chemotherapy is associated with prematurity, congenital malformations, neurocognitive dysfunction, cancer and fertility problems in the fetus. There will be concerns about the use of radiotherapy to treat malignancy during pregnancy; the rapidly growing fetus is particularly radio-sensitive, and effects will depend on gestational age and the exposure dose. Concerns related to surgical intervention are the same as those for other surgical procedures in pregnancy (see Chapter 8, Incidental surgery in the pregnant patient).
In addition, the normal psychological stresses of pregnancy and delivery are especially intense if the mother has (or has had) cancer. The physiological demands of normal pregnancy may stress the more susceptible systems in the mother with malignant disease; for example, anaemia may become more pronounced, and mild cytotoxic-induced cardiomyopathy may become more severe. Finally, there may be direct effects of the malignancy or its treatment on the uterus and birth canal, such as scarring from cervical or perineal surgery, or abdominal adhesions.
A particular form of malignant disease affecting pregnancy is that arising from the placenta itself (gestational trophoblastic neoplasia), comprising hydatidiform mole, invasive mole, choriocarcinoma and placental site trophoblastic tumour. The incidence is 1 in 714 live births, and it is more common at the extremes of reproductive age, in east and southeast Asia, and if previous pregnancies have been affected. The pregnancy itself is non-viable, and concerns about the fetus do not apply. These tumours generally respond well to chemotherapy, even if metastatic spread has occurred, with a mortality below 1%. Molar pregnancy may be associated with hyperemesis, hypertensive disease, anaemia, ovarian cysts and, rarely, hyperthyroidism. Surgical evacuation may be associated with excessive bleeding, and may be followed by pulmonary oedema or acute lung injury, possibly related to trophoblastic pulmonary embolism.
Management options
General care is directed towards the particular organs or systems affected by the malignancy itself and its treatment. Thus all mothers who have or have had a malignancy require careful antenatal assessment, paying particular attention to haematological and major organ function, with decisions concerning anaesthetic management made accordingly. Some mothers may knowingly have put their lives at risk in order to give the fetus the best chance of survival, and this must be respected when managing their analgesia and anaesthesia.
In trophoblastic neoplastic disease, uterine evacuation may be adequate surgical management, but hysterectomy may be required in more invasive disease, especially in older women. Surgery may also be required for torsion of, or haemorrhage into, ovarian cysts. Chemotherapy may be required if human chorionic gonadotrophin levels remain elevated or in metastatic disease.
In terms of anaesthetic management, the above considerations should be taken into account and appropriate measures taken regarding investigation (including liver and thyroid function blood tests and chest radiography), monitoring and management. General anaesthesia is usually recommended, since uterine bleeding may be rapid and severe, and blood should be cross-matched and ready before surgery.
Key points
• Malignancies may be present before pregnancy, may develop or be diagnosed during pregnancy, or may arise from the pregnancy itself.
• Problems may be related to general effects of malignancies or those related to the interaction between malignancy, its treatment and pregnancy.
• Gestational trophoblastic neoplasia represents a particular form of malignancy.
Further reading
Basta P, Bak A, Roszkowski K. Cancer treatment in pregnant women. Contemp Oncol (Pozn) 2015; 19: 354-60.
Morice P, Uzan C, Gouy S. Gynaecological cancers in pregnancy. Lancet 2012; 379: 558-69.
Salani R, Billingsley C, Crafton SM. Cancer and pregnancy: an overview for obstetricians and gynecologists. Am J Obstet Gynecol 2014; 211: 7-14.