There are many different factors that influence fertility. This discussion is limited to uterine factors that affect fertility and treatment options.
The anatomy of the uterus is made up of the fundus, body and the cervix. The endometrial cavity lies within the body of the uterus and is lined by the endometrium, and is surrounded by a muscular layer called the myometrium. The fallopian tube or uterine tubes are connected to the endometrial cavity at its proximal end (corned end) and at its distal end being very close to the ovary (fimbrial end). Some anatomists consider the fallopian tube as part of the uterus.
Do fibroids affect fertility?
Fibroids are a heterogeneous group of benign tumours of the uterine muscle. It’s a common occurrence in woman in their reproductive age. They may be small, large, single or multiple and can lie in any position. The relationship between fibroids and infertility has long been a concern. In clinical pregnancy, implantation and ongoing pregnancy rates were found to be significantly lower in inpatients with fibroids (Pritts et al. F&S 2008).
Fibroids can cause distortion of the cavity, abnormal endometrial receptivity, and can impair gamete transport.
Fibroids are classified according to position.
The question to answer is:
- Which fibroids affect fertility?
- And does removal improve fertility?
Subserosal – No effect
Submucosal & Intracavitary – Affects fertility. Removal will significantly improve fertility
Intramural – Affects fertility , but removal usually does not improve outcome, except if the cavity is distorted or size greater than 5cm
This condition causes diffuse enlargement of the uterus, with distortion of the normal anatomy. The patient presents with heavy bleeding and or period pains. Adenomyosis is caused by the endometrial tissue invading into the myometrium. Adenomyosis is also associated with an increased incidence of infertility, this is mainly due to disturbed peristalsis, defective implantation and abnormal endometrial growth. (Campo et al 2012. Repro bio med J)
Treatment however is limited and there is no evidence as yet that treatment improves fertility outcome. Treatment is either by surgery or the use of GnRH analogues.
Congenital Uterine Anomalies
Congenital Uterine Anomalies results when there is incomplete fusion of the mullerian ducts.
The most common anomalies are septate, arcuate and bicornuate uterus. Their presence also influences infertility and can cause abortions.
Diagnosis is by either an HSG or Hysteroscopy. In the presence of a septate or arcuate uterus- treatment improves the outcome. Treatment is by hysteroscopic resection.
In the presence of more complex anomalies, a conservative approach is better and surgery to be delayed.
Synaechia / Adhesions
Synaechia or Intrauterine adhesions can also cause infertility and or abortions. These may occur in patients that may have had previous TB, endometritis or repeated D&C’s. These patients present with amenorrhoea (no menstrual bleeding) or oligo amenorrhoea (very little, minimal menstrual flow). Diagnosis is also by either an HSG or hysteroscopy. Treatment improves outcome and is done by Hysteroscopic resection of adhesions.
Fallopian tube damage
We will discuss fallopian tube damage as some would consider the tube as an extension of the uterus. The most common cause of fallopian tube damage is PID (Pelvic inflammatory disease). It’s a common cause of infertility especially in developing countries. Proximal tubal occlusions are very difficult to rectify and patients often require IVF. Peri-tubular adhesions can be treated surgically.
For Distal Tubular occlusions – if the fallopian tube is not badly damaged- Tuboplasty (opening of the blocked fallopian tube surgically) can be attempted. If badly damaged will require IVF. In patients who have distal obstruction and hydrosalpinx (water in the fallopian tubes) and who are undergoing IVF, there is a 50% reduction in the success rates of IVF. Therefore the treatment of the hydrosalpinx first before IVF is mandatory to improve success rates. The fluid in the tube can be toxic to the embryos.
Drainage of hydrosalpinx is often not the best treatment as reoccurrence of fluid collection is high. Removal of fallopian tubes (salpingectomy) can be done (but may compromise ovarian reserve in some patients).
The best treatment at present is proximal occlusion of the fallopian tube either by laparoscopy or hysteroscopy.
– with thanks to Dr Dasoo a Fertility Specialist from BioART fertility clinic