Endometrial or uterine polyps are soft, fingerlike growths which develop in the lining of the uterus (the endometrium). They develop because of excessive multiplication of the endometrial cells, and are hormonally dependent, so that they increase in size depending upon the estrogen level. They can usually be detected on an ultrasound scan if this is done mid-cycle, when estrogen levels are maximal, but are easily missed if the scan is not done at the right time of the menstrual cycle. Polyps are usually asymptomatic and do not cause any problems. They are usually found on a routine vaginal ultrasound scan. It’s easy to miss the polyp if the scan is done at the wrong time of the menstrual cycle. The best way to pick up a polyp is by doing the scan on Day 10- 12 (when the endometrial thickness is maximal, because of high estrogen levels). A sono-salpingogram is a very effective way of diagnosing a polyp. While they can sometimes be seen on a HSG as a constant filling defect within the cavity, they can often be missed as well, because they are small. The definitive technique to diagnose a polyp is a hysteroscopy. Hysteroscopy is a procedure that allows your doctor to look inside your uterus in order to diagnose and treat causes of abnormal bleeding. Hysteroscopy is done using a hysteroscope, a thin, lighted tube that is inserted into the vagina to examine the cervix and inside of the uterus. Hysteroscopy can be either diagnostic or operative.
In the past, polyps were often removed by doing a D&C (and this may have been the reason some women with “unexplained infertility” got pregnant after a D&C – not because the D&C “cleaned the uterus”, but However, it’s still fairly controversial as to whether small polyps affect fertility. Many doctors will leave a small polyp alone, as they do not think it affect fertility at all. However, others will routinely remove them – especially prior to doing IVF. This is one of those gray zone areas of medicine where it’s always very hard to make a definite decision because different doctors have different opinions as to what needs to be done. Most doctors would take the approach that anything inside the uterine cavity needs to be removed before putting an embryo inside the uterus; and they would automatically and reflexively suggest an operative hysteroscopy to remove the polyp before doing the IVF cycle. This is standard medical advice and is perfectly reasonable. However, there are other doctors who feel this is unnecessarily aggressive, because there is no proof that a small polyp can affect embryo implantation. This is a vexed issue which is very controversial because there aren’t enough studies to be able to come to a definitive conclusion. This is hardly surprising. Most IVF specialists will see only infertile women, so any time they see someone with a polyp, they will assume that the polyp is the cause for the infertility and will advise removal.
Hysteroscopic removal of polyps in women with unexplained infertility may increase their chances of becoming pregnant, concludes an intervention review conducted by the Cochrane Menstrual Disorders and Subfertility Group. Abnormalities in the uterine cavity, such as endometrial polyps, submucous fibroids, uterine septum, and intrauterine adhesions, may disrupt the process of implantation of a fertilized egg into the inner layer of the cavity of the uterus. In subfertile women with a uterine cavity abnormality, removal of these abnormalities using hysteroscopy may be recommended to help increase the odds of pregnancy.
Although the practice is theoretically sound, it is unknown whether hysteroscopic removal of uterine cavity abnormalities results in a definitive increase in pregnancy and live birth rates. To better understand the effects of hysteroscopic removal of uterine cavity abnormalities in women with otherwise unexplained subfertility or before commencing assisted reproductive technology, such as intrauterine insemination (IUI), in vitro fertilization, or intracytoplasmic sperm injection, researchers reviewed and analyzed available relevant studies. Live birth and hysteroscopy complications were primary outcomes, and pregnancy and miscarriage were secondary outcomes. The second study involved 204 women with various fertility problems who also had polyps. The results of the analysis showed that hysteroscopic removal of polyps before IUI, compared with diagnostic hysteroscopy and biopsy, significantly increased the odds of clinical pregnancy. The researchers deemed the quality of this study to be high. Although this analysis showed an important increase in pregnancy rates, additional studies are needed to confirm the results. The real clinical value of hysteroscopic removal of uterine cavity abnormalities to increase fertility rates in subfertile women remains unknown. The limited evidence shows that hysteroscopy may improve the odds of a clinical pregnancy. However, more studies are needed before hysteroscopy can be recommended as a fertility-enhancing procedure, concluded the researchers.
Removing polyps and other uterine cavity abnormalities via hysteroscopy in women with unexplained infertility may increase their chances of becoming pregnant. Also, the analysis shows the practice is associated with important increases in pregnancy rates or at least a benefit trending toward increased fertility, but the evidence is limited and additional, larger studies are needed.