At one time, infertility due to female factors was thought to be the reason behind all fertility problems. Today, experts recognize that female infertility accounts for about 40% of all infertility cases, while male infertility accounts for 40% to 50% of cases, with the most common reasons being tubal blockages, ovulation problems and endometriosis. Unfortunately, around 15% to 20% of cases have no obvious cause associated with them, leading to a diagnosis of unexplained infertility.
Blockage of the fallopian tubes can be suggested on a hysterosalpingogram (HSG), but it is important to do a laparoscopy to confirm whether this is the case or not. Sometimes inadequate pressure when inserting the dye during a HSG can lead to a suggestion of blockage when one doesn’t exist. Laparoscopy also gives the opportunity of taking a close look at the tubes to decide on the usefulness of tubal surgery to open them.
The most common cause of blocked tubes is infection, and the most common infection implicated is chlamydia. About 70% of women who have blocked tubes have had a chlamydia infection, though half the time it will have been silent and they will not have even been aware of it.
Where the tubes look otherwise quite normal and the block is close to the uterus, or where scar tissue adhesions are causing a distinct blockage, it is possible to do tubal surgery to open them up. Adhesions can sometimes be broken down through the laparoscope laparoscopic adhesiolysis. Other times or where a small segment of blocked tube needs to be removed, an open operation is needed. The tube may be swollen and full of fluid (hydrosalpinx) or the damage may be more severe and close to the finger-like fimbrial end of the tube where the egg first enters. In these situations tubal surgery is much more unlikely to be successful and in-vitro fertilisation (IVF) will often be suggested in the first instance. In any case, if pregnancy hasn’t happened within 12 months following tubal surgery, IVF should be considered as the chance of success after this time is much lower.
Reversal of sterilisation is successful about 50-70% of the time, but is only rarely available on the NHS.
It is ovulation and the hormone changes that subsequently follow which leads to the normal menstrual cycle. Thus, irregular periods strongly suggest that an egg is not being released each month.
Sometimes women still cycle but ovulation does not happen every month. The test for ovulation is the day 21 progesterone (for a 28 day cycle), and the term anovulation means that ovulation is not taking place.
Sometimes women don’t ovulate because of an overactive pituitary gland, leading to high levels of the hormone prolactin. Bromocriptine is a drug that is used to suppress this excess and it also leads to the return of ovulation in most cases.
Polycystic Ovary Syndrome (PCOS)
Another cause of anovulation is PCOS. Hormonal problems are sometimes found and on scan the ovary has lots of small cysts around the edge. These are not harmful in themselves, just a sign that eggs have started to develop, but never got released.
Clomifene Citrate (Clomid)
Commonly used to start the ovaries ovulating again. Clomid is taken on days 2-6 of a cycle and it ‘kick-starts’ the ovary into making and releasing an egg.
A day 21 progesterone level in the first cycle will check that it has worked, but some women need a higher dose. It is a safe drug but, as with most ovulation treatments, it increases the risk of a multiple pregnancy, such as twins. This happens in about 1 in 20 women treated with clomiphene.
A treatment that is used in PCOS where clomiphene is unsuccessful. Several small holes are made in the ovary during a laparoscopy, and this reverses the hormone problems associated with the disease.
The success rate depends on many factors, but typically around 50% of women fall pregnant within 1-2 years of treatment and by 3 years about 75% are successful.
A more intensive treatment, which uses injections of hormones on a daily basis and close ultrasound monitoring of the ovary’s response. The aim is to produce several good quality eggs and time their release with intercourse.
Side effects include multiple pregnancy (10-20%), an increased risk of ectopic pregnancy and a condition called ovarian hyperstimulation syndrome, where an unexpectedly excessive response occurs and large ovarian cysts develop.
The success rates vary greatly depending on the individual situation, but 40-85% after 6 treatment cycles is typical. Success after 6 cycles is less likely, though not impossible, and IVF is usually advised if this is unsuccessful.
In vitro fertilisation involves a stimulation cycle with ultrasound monitoring, similar to that described above. The eggs are retrieved, usually by ultrasound-guidance and conception takes place in the laboratory.
About 72-80 hours later, the embryos are replaced into the uterus, through the cervix. The success of IVF depends very much upon the age of the woman and the duration of infertility so far, but average success rates of 16-25% per cycle are usual.
Side effects are similar to those of ovarian stimulation and the risk of multiple pregnancies depends upon the number of embryos replaced.
Endometriosis is a condition where spots of the lining of the uterus (endometrium) are found inside the pelvis on the ovaries, the back of the uterus and the ligament supports of the uterus.
Although extensive endometriosis involving the tubes and distorting the ovary are clearly likely to interfere with egg transport and ovulation, it is less clear how mild to moderate endometriosis exerts an effect on fertility.
The aim of treatment is to remove all the endometriosis by either cutting it out or burning it away with diathermy or laser, break down any associated adhesions and leave as much normal ovary tissue as possible.
Mild to moderate endometriosis can usually be managed laparoscopically, but more severe cases require open surgery. Drug treatment may be useful after surgery, but as a primary treatment for infertility, it only delays pregnancy further.
Apart from being terribly frustrating, unexplained infertility means that treatment is not directed at any known cause. Approximately 60% of couples with unexplained infertility of less than 3 years duration will fall pregnant in the next 3 years without any treatment at all. Recent analysis of all the studies of clomiphene has not found it to be beneficial.
One useful treatment option is ovarian stimulation combined with a direct insemination of prepared and ‘optimised’ sperms from the partner. This involves the usual monitoring of ovarian stimulation and insemination around the time of ovulation, which is achieved by passing a speculum, as during a smear test, and injecting the sample into the uterus.
Pregnancy rates are typically 15% per cycle. If this is unsuccessful after 6 cycles, then IVF is usually advised.
For more information on female infertility check out our pregnancy videos.