Colorectal cancer has an incidence in pregnancy of approximately 0.002%.1
Symptoms and signs include nausea, vomiting, abdominal pain, rectal bleeding and altered bowel movements, abdominal distension, palpable mass and anaemia. Diagnosis of colorectal pathology during pregnancy is often challenging as many of the above indicators can be attributed to the physiological and gastrointestinal changes of pregnancy. This often leads to delay in referral and investigation which allows opportunity for advancement of disease with a worsened prognosis.
Optimum evaluation for suspected colorectal cancer should include endoscopy and biopsy and abdominal radiology which are often delayed or avoided because of the potential effects on the unborn fetus.2
Once the diagnostic challenges are overcome, the gestation of the pregnancy and potential viability of the fetus may limit the treatment of the pregnant woman. Management of colorectal cancer ultimately should comprise therapy to the mother and delivery of the fetus at earliest agreed opportunity.
Treatment of colorectal cancers should be individualised to each patient. Surgery is usually recommended with or without the use of adjuvant therapy. For those cancers diagnosed within the first half of the pregnancy, a full discussion of the options available to the woman should take place. This may include recommendation to terminate the pregnancy in order to optimise surgical resection and in consideration of potential compromise to fetal development that is associated with adjuvant therapy. If diagnosis is made later in the pregnancy, treatment may be delayed until delivery of the infant at an agreed gestation, although the mother will be at risk of disease progression.
In this case, the antenatal symptoms of constipation and anaemia were not investigated further as they were attributed to common benign symptoms of pregnancy by the community midwife. The history of rectal bleeding was not disclosed by the patient antenatally and was only obtained retrospectively after delivery. As the anaemia had showed some response to haematinics, the patient therefore remained under midwife-led care throughout her pregnancy and was not referred for medical opinion.
During routine antenatal scans the rectal tumour was not identified. This could be a result of several factors, including (a) the tumour size at the time of ultrasound not being large enough to be seen, (b) during routine antenatal ultrasound the primary focus of the sonographer is the uterus and the fetus, (c) midwife sonographers may not be sufficiently experienced in colorectal pathology during routine antenatal ultrasound.
Colorectal tumours are one of the many rare causes for labour dystocia. These rarer causes that first presented in labour have been described in the literature. A large retroperitoneal tumour of unknown origin caused obstructed first stage of labour in a multiparous woman, and emergency caesarean was performed.3
Retroperitoneal sarcomas were diagnosed in late pregnancy in two women with large pelvic tumours that prevented engagement of the presenting part at term and elective caesarean was planned in both cases.4
Other rare maternal causes for obstructed labour include vesical calculus and pelvic kidney.5–8
In another case, tumour praevia presented in a term pregnancy and was later confirmed as papillary adenocarcinoma.9
A report of two cases of obstructed labour at full dilatation caused by presacral tumours have previously been described.10
In the first case, a retroperitoneal simple cyst was found to have caused second-stage delay and delivery was made using Barton's forceps. In the second case, a malignant haemangioendothelioma prevented the engagement of the fetal head at full dilatation and caesarean delivery was performed.
The mode of delivery in cases of known colorectal cancer with no evidence of obstructed labour remains controversial. A case of prolapsed rectal cancer through the anus during vaginal delivery has been described.11
The decision regarding mode and timing of delivery should be assessed on an individual basis by a multi-disciplinary team.
- We aim to heighten clinical suspicion and recognition of colorectal pathology as a rare cause for obstructed labour.
- Clinicians need to be alert to the warning signs of colorectal cancer, and if signs and symptoms cannot be differentiated from pregnancy-attributed symptoms, the woman should be appropriately referred for further investigation. Early investigation of bowel symptoms can optimise labour management and both maternal and fetal outcome can be improved.
- The symptom of rectal bleeding should be actively sought during history taking in patients with other gastrointestinal symptoms.
- There is need for multidisciplinary approach to care of the pregnant woman with colorectal cancer and should involve experts within the fields of obstetrics, neonatology, surgery and oncology at the earliest opportunity.