Imagine finding out that you have an ovarian cyst while pregnant.

That happened to my patient, Madam Sim (not her real name), who came to see me at week 12 of her second pregnancy two years ago.

Ovarian cysts are not uncommon and most are benign, but not all are.

From the ultrasound scan, Madam Sim, 30, had a cyst on her right ovary.

Simple cysts smaller than 5cm are usually benign; many will disappear. However, she had a 10cm cyst with solid nodules and increased blood flow, which are features linked to cancer.

Moreover, a suspicious looking cyst detected in early pregnancy creates a dilemma.

One can only tell if such a cyst is cancerous after it has been surgically removed. Features seen on scans are speculative at best.

So, should she undergo cyst removal - a major operation - while she is pregnant with an unborn life at stake? Waiting seven months to operate - that is, after the pregnancy - may allow what might well be an early stage cancer to spread and worsen.

If the cyst was cancerous, something highly curative (at its early stage) might end up in an advanced terminal stage.
If a provisional assessment finds a cancerous cyst while the patient is still on the operating table, doctors will have to decide on the spot if more organs - such as the womb and ovaries - have to be removed.

That means the foetus will have to be aborted.

Madam Sim listened as I explained these scenarios.

Finally, she chose to remove the cyst first to determine if it was cancerous and, if so, to proceed with chemotherapy.

The best time to remove an ovarian cyst during pregnancy is between weeks 13 and 16. The pregnancy would have stabilised while the womb size is not so big as to obstruct the procedure.

Madam Sim underwent the surgery at week 14.

The cyst was removed and immediately frozen, sliced and studied under the microscope - while she was still on the operating table.

The next course of action hinged on the provisional diagnosis. If the cyst was determined to be clearly benign, the operation would end with the removal of the ovarian cyst.

If it was assessed to be cancerous, and the cancer had spread, both ovaries and the womb if necessary would need to be removed.

Also, there is a 5 per cent risk of misdiagnosis. A confirmatory diagnosis by conventional histology (study of tissue under the microscope) must always be done but the results may take days.

Madam Sim’s “frozen section” showed a type of ovarian cancer that is highly suitable for chemotherapy.

So for young women wanting to preserve fertility, removal of the affected ovary would suffice.

Madam Sim and her unborn child withstood the operation well. The plan was that chemotherapy would start one month after the operation.

But that 5 per cent chance of error was to dog her. A week later, the confirmatory diagnosis found a much more aggressive cancer type. It meant that more of her organs needed to be removed prior to chemotherapy.

So, at week 16 of her pregnancy, she had her appendix, omentum (fat within the abdominal cavity) and lymph nodes removed.

Three weeks after this second operation, she commenced chemotherapy. As was likely to happen, her hair fell out and she grew weaker.

However, the foetus did not succumb to the possible chemotherapy effects, such as intrauterine growth restriction - where the baby may not grow as well - during the second half of the pregnancy.

In fact, her foetus grew so well it was slightly bigger than average.

Madam Sim completed six cycles of chemotherapy.

She opted for a Caesarean delivery as she had decided to have her womb and her remaining ovary removed following delivery.

Her baby was perfectly formed and when I saw mother and child six months ago, both were doing very well.

Dr Chee, medical director of The Obstetrics & Gynaecology Centre, the Singapore Medical Group, has been treating obstetrics and gynaecology patients for 12 years. She sub-specialises in maternal foetal medicine
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By Dr Chee Jing Jye
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