The success rates following tubal surgery will depend on the severity of the disease. Careful pre-operative assessment, including semen analysis and often hysterosalpingography and laparoscopy, is required.
The commonest site of tubal damage is at the fimbrial end (opening near the ovaries –Figure 9.1), with birth rates after surgery in the order of 25 per cent. Surgery for proximal tubal occlusion (the blockage is close to the uterus) is more successful, with live birth rates of 50% and ectopic rates of 10%. Just over a half of intrauterine pregnancies following tubal surgery may occur more than one year after surgery. Reversal of sterilisation, with removal of clips and re-anastomosis (reconnection), carries a relatively high success rate of up to 80%.
Tubal microsurgery involves the use of magnification as well as the adoption of a set of techniques including the use of special instruments, minimal handling of the Fallopian tubes and fine non-reactive suture material. There have been no controlled trials to prove conclusively an advantage over conventional surgical techniques but several surgical teams have reported improved success rates. It is technically possible to transplant Fallopian tubes and large numbers of these organs would undoubtedly be donated by women undergoing sterilisation or hysterectomy
(hysterectomy). Research interest in this area seems to have diminished following the development of IVF (Q10.24).
IVF
Introducing IVF - In Vitro Fertilisation (USA
Fertilization)
IVF literally means fertilisation outside
the body. IVF was initially developed for women who had severe tubal disease or who had their Fallopian tubes removed but this treatment has also proved successful for unexplained
infertility and male factor infertility.
IVF is a major treatment in infertility
when other methods of assisted reproductive
technology have failed.A typical IVF treatment cycle is outlined in (Figure 10.3). Originally, eggs were collected laparoscopically (laparoscopy) but we now collect the eggs by ultrasound guidance usually through the vagina.
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Egg Donation and Egg Sharing
Some women are unable to produce healthy eggs either because they have reached their menopause early, they are approaching their menopause (Figure 10.7) or because their eggs carry abnormal genes. The only realistic chance of a successful pregnancy in these circumstances is if another woman donates some of her eggs. There are some remarkable women who, for altruistic reasons, come forward voluntarily and go through the regimen for IVF egg collection and donation. Egg donors should usually be aged 35 years or less.
The demand for egg donation greatly exceeds supplies. There are many women who have healthy eggs and need IVF but for economic reasons IVF is beyond them. The combined requirements of funding for IVF for the less privileged and of others for egg donors has led to the development of eggs sharing. If a woman requiring egg donation will fund the two treatments, she may receive perhaps half the eggs provided by the woman who hasQuality eggs but cannot afford the treatment.
Tubal Surgery and IVF Compared
Information about success rates is essential for couples to make informed decisions. In vitro fertilization (IVF) provides an alternative to tubal surgery. For mild tubal disease and previous sterilisation, tubal surgery is probably the treatment of first choice. With severe tubal disease, IVF carries the better success rate. For intermediate disease, the optimum method in terms of success is less certain. IVF is becoming increasingly successful (Figure 10.5) and appropriately more popular (Figure 10.6).
The merits of tubal surgery and assisted reproduction (Assisted Reproductive Technology ART) need careful comparison. In-vitro fertilisation is becoming more readily available with a corresponding reduction in the use of tubal surgery.
IVF is associated with a higher incidence of multiple pregnancy. Perinatal mortality rates following assisted conception procedures are treble that of spontaneous conception although most of the increase is related to multiple pregnancy. There is a five-fold increase in perinatal mortality (stillbirths and first week losses) with triplets compared with singletons. The predicted costs associated with delivery of each baby for a singleton pregnancy in the USA in 1991 was $9,845, for a twin pregnancy $18,974 and for triplets $36,588. Between 1986 and 1991, assisted reproduction techniques were found to be responsible for 35% of twins and 77% of higher order pregnancies.
In the NHS only about 25% of purchasing authorities are currently supporting IVF treatment and the number is falling. There can be little doubt, that from a purely economic point of view, a greater number of pregnancies could be achieved with a given amount of funding using low tech treatments. Many couples would prefer tubal surgery in the first instance and the opportunity to conceive naturally, only resorting to IVF if this fails.