In many cases, a couple cannot achieve a pregnancy or they have had failed IVF cycles or recurrent miscarriage despite the fact that everything looks fine: there are no hormonal problems or male infertility. In many clinical studies, it has been confirmed that women with multiple failures after IVF or with multiple miscarriages have anatomical uterine abnormalities. These can easily be corrected with hysteroscopy.
Uterine abnormalities are innate in some women, who do not know about it until they start trying for a pregnancy, because uterine abnormalities cause miscarriages or premature delivery. Until then, they usually cause no problem at all. Uterine abnormalities are quite common (6.7% in the general population) and their correlation with recurrent miscarriage (16-25% in women with recurrent miscarriage) and infertility (difficulty to achieve a pregnancy) is well established.
The most common uterine abnormalities are:
• Septate – it divides the cavity of the uterus in two
• Arcuate uterus – a formation like a small septate distorts the cavity of the uterus
• Unicornuate – only one half of the uterus has developed (the uterus normally consists of 2 parts that develop and form together the uterus)
• Bicornuate – the uterus has 2 cavities instead of 1, because of abnormal growth
When a uterus has such abnormalities, it is difficult to sustain a pregnancy, which increases the risk of miscarriage. However, women with uterine abnormalities may perfectly carry a baby to full term with no problems.
All the above abnormalities are also causes of infertility. In recent studies concerning women with a septate, which is the most common uterine abnormality, it has been shown that:
• The risk of miscarriage or premature delivery is significantly reduced when the septate is surgically corrected (removed)
• A septate is more common among women with infertility, which indicates a correlation. Subfertile women with a uterine septate and no other cause of infertility (as diagnosed by laparoscopy) have a significantly higher chance of achieving a pregnancy following the surgical removal of the septate.
It is thought that even a small septate may affect embryo implantation and early pregnancy. The septate structure is different compared to the normal endometrium and cannot sustain implantation.
An arcuate uterus is quite common in women with recurrent miscarriage.
Most uterine abnormalities can be diagnosed by means of hysteroscopy, which helps the doctor examine the uterine cavity. Hysteroscopy offers the advantage that the patient can be diagnosed and treated (removal of the septate) at the same time, but its disadvantage is that it consists a surgical procedure.
Hysteroscopy is the preferred surgical method in 90% of the cases of uterine abnormalities. Laparoscopy is necessary only in case of very large formations. Hysteroscopy, when performed by an experienced doctor, offers excellent clinical results and involves a low risk of complications.
Recent clinical studies:
‘Hysteroscopic resection of the septum improves the pregnancy rate of women with unexplained infertility: a prospective controlled trial’
Mollo A. et al 2009 Fertility and Sterility Vol. 91, No. 6, p. 2628-2631
‘Prevalence and diagnosis of congenital uterine anomalies in women with reproductive failure: a critical appraisal’
Saravelos S. et al 2008 Human Reproduction Update Vol. 14, No. 5, p. 415-429