Fibroids and polyps: which ones interfere with IVF, and which ones don’t

Fibroids are extremely common: they are found in a large proportion of women over the age of 35. Endometrial polyps are too. The question is therefore not ‘do I have any?’, but ‘does this one cause a problem?’. Here’s how doctors approach the issue.

What is a fibroid?

A fibroid (or myoma) is a benign tumour of the uterine muscle. The international FIGO classification describes them according to their location:

• Submucosal (types 0 to 2): these protrude into the uterine cavity, where the embryo implants.
• Intramural (types 3 to 5): within the muscle layer.
• Subserosal (types 6 and 7): on the outer surface of the uterus.

Their effect on fertility

Submucosal fibroids significantly reduce the chances of implantation and increase the risk of miscarriage. Their removal via hysteroscopy improves outcomes: this is the clearest indication.

Subserosal fibroids have no proven effect on fertility. They are not removed for IVF, unless they are very large or causing symptoms.

Intramural fibroids are a grey area. Meta-analyses suggest a moderate reduction in the chances, particularly if they are larger than 4 to 5 cm or if they distort the uterine cavity. However, myomectomy (often performed via laparoscopy or laparotomy) has not been shown to improve birth rates in these cases, and it comes at a cost: a uterine scar, a healing period, and sometimes a subsequent recommendation for a caesarean section. The decision is made on a case-by-case basis.

Endometrial polyps

These are benign growths on the lining of the uterus, often detected by ultrasound or during a hysteroscopy. Small polyps (less than one centimetre) are unlikely to have much effect; nevertheless, many doctors prefer to remove them before an embryo transfer, as the procedure is straightforward: an operative hysteroscopy lasting a few minutes, often carried out on an outpatient basis, which also allows the polyp to be analysed. An older randomised trial showed more pregnancies after polyps were removed before insemination.

Diagnosis

• Pelvic ultrasound, ideally in 3D, during the first half of the menstrual cycle.
• Hysterosonography: ultrasound following the injection of saline into the uterine cavity; highly accurate for detecting polyps and submucosal fibroids.
• Hysteroscopy: direct visualisation of the uterine cavity, with the option of treatment during the same procedure.
• MRI: to map multiple fibroids prior to surgery.

How long should you wait after surgery?

• After hysteroscopic removal of a polyp: often just one cycle, sometimes even the very next cycle.
• After hysteroscopic resection of a submucosal fibroid: generally one to three months, sometimes with a follow-up hysteroscopy to check for adhesions.
• After abdominal myomectomy: often three to six months, depending on the depth of the scar.

A common strategy for patients who travel: carry out egg retrieval and freeze the embryos, then treat the uterus, and subsequently schedule a frozen embryo transfer. No time is lost as far as egg quality is concerned.

What about drug treatments?

Some medicines temporarily reduce the size of fibroids, but they block ovulation and the fibroids grow back once treatment stops. They are sometimes used to prepare for surgery, but rarely to improve fertility directly. Fibroid embolisation is generally not recommended for women wishing to become pregnant.

What I recommend sending to the clinic

The ultrasound or MRI report, including, for each fibroid, its size, location and FIGO classification, if indicated. With this information, the doctor can often determine remotely whether a procedure will be required before the embryo transfer — and thus estimate the duration and cost of the stay. See endometriosis and adenomyosis for other uterine causes.

Frequently asked questions