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Effective Health Care Reviews: Management of Subfertility

The third Effective Health Care bulletin from the University of Leeds published in 1992 covered this interesting and important topic. This is a thorough but highly readable document that richly repays an hour in an armchair.

The size of the problem

A health authority with a population of 250,000 will have 46,000 women aged 20-44 years, with about 230 (0.5%) new consultant referrals each year. The proportion of women of childbearing age experiencing subfertility is 9-14%. A useful definition of subfertility is failure to conceive after two years during which there has been intercourse and no use of contraception. After one year 80-90% of couples attempting to conceive are successful, rising to about 95% after two years.

Causes of subfertility

There is no explanation for infertility in 30% of couples. In about 19% there is a male factor (azoospermia for instance), in 27% there is ovulatory failure in the woman, in 14% tubal damage exists, and endometriosis or other causes make up about 5% each.

Does treatment work?

To some extent this depends on how the question is framed. Firstly, patients (couples) undergoing treatment may experience spontaneous pregnancies; measures of effectiveness should take this into account. Again, in determining a reproductive outcome there are several criteria which have been used as measures; these include biochemical evidence of pregnancy, a clinical pregnancy, an ongoing pregnancy, births, and maternities. In general, the numbers fall as one proceeds along this list; maternities, that is the proportion of couples who have a child, is probably the hardest outcome measure.

The Effectiveness bulletin does an excellent job of introducing the reader to the complexities involved in evaluating effectiveness. In addition, it has a number of appendices listing many reports, studies, reviews and RCTs of different methods of treatment with main outcomes. It makes sobering reading to realise that the number of successful maternities is really quite low for many techniques (although the latest data reported are from about 1990/1).

Individual sections on male subfertility, and female problems of tubal factors, ovulatory dysfunction and endometriosis, as well as unexplained subfertility are all reviewed as to the results of studies, and the methods which are most effective (if that is known).

Assisted conception methods

The most commonly practised technique is IVF-ET (In-vitro fertilisation with embryo transfer). Eggs and sperm are collected, mixed in the laboratory and incubated for 2-3 days until fertilisation is achieved, and when achieved, the fertilised eggs injected into the uterus.

The bulletin gives a number of tables comparing pregnancy and maternity rates for IVF-ET and other techniques and for different causes of subfertility, but the success rate of 14% of couples having a child seems to be typical.

The average reproductive experience of all UK patients receiving IVF-ET in 1990 was followed, and the results have been collated for the 'national experience'.

And their problems
  • Between 1978 and 1987 24% of births after IVF-ET were preterm, compared with 6% for natural conceptions.
  • Some 26% of births were multiple births (22% twins, 4% triplets), compared with the natural rate of 1%.
  • Low birth weight is a problem: 32% weighed less than 2500g, and 7% weighed less than 1500g. This compares with 7% and 1% respectively for all births.
  • There was a higher rate of perinatal mortality of 19/1000 pregnancies and 26/1000 live births with assisted conception, compared with 8/1000 pregnancies and 16/1000 live births for natural conceptions.
  • Congenital malformations are not a problem.
Cost effective purchasing There is a really good discussion about the issues involved with cost-effective purchasing. Based on a hypothetical district health authority with a population of 250,000, it costs out the typical programme of subfertility treatments expected. The costing also adds in other charges, to come up with an overall figure of £880,000 (1992/3 prices), though the bulletin goes on to explain why funding a comprehensive service should be less costly at about £750,000. There are, in addition, a number of helpful and considered guidelines on organisation and management of services.




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