Gamete intrafallopian transfer in older women: effect of limiting number of gametes transferredBMJ 1994; 309 doi: https://doi.org/10.1136/bmj.309.6953.510 (Published 20 August 1994) Cite this as: BMJ 1994;309:510
- C J Redgment,
- T Al-Shawaf,
- J G Grudzinskas,
- I L Craft
- London Gynaecology and Fertility Centre, London W1N 1AF Academic Department of Obstetrics and Gynaecology, Royal London Hospital, London E1 1BB
- Correspondence to: Dr C J Redgment, Panaga Hospital, c/o Brunei Shell Petroleum Sbn Bhd, Seria 7082, Brunei Darussalam, North Borneo.
- Accepted 16 March 1994
The Human Fertilisation and Embryology Authority and its predecessors have restricted the maximum number of oocytes and embryos that can be transferred in gamete intrafallopian transfer and in vitro fertilisation to minimise the risk of multiple pregnancy. The current maximum of three practically eliminates the risk of quadruplet or higher order pregnancies.
Women in their fifth decade have reduced fecundity and an increased risk of miscarriage after spontaneous or assisted conception.1, 2 Because of this and the current restrictions we are concerned that such women might use donor oocytes from young women to overcome infertility, although they might have an acceptable chance of pregnancy if a flexible number of their own oocytes could be used. We therefore retrospectively assessed the effect of the restrictions on the outcome of gamete intrafallopian transfer in older women.
Subjects, methods, and results
We reviewed treatment cycles of gamete intrafallopian transfer of known outcome in women aged 40 or older that had occurred between 1 January 1987 and 31 July 1993. Of these, 151 were performed before 7 October 1987 (group 1) and had a flexible number of oocytes transferred based on age and other factors. After that date, 731 cycles were performed under the restrictions of the licensing authorities (group 2); the maximum number of oocytes transferred was four until 1 August 1991 (625 cycles) and three after that (106 cycles).
The technique and selection of patients for treatment at this unit have not changed,1 and the mean age was 41.4 and 41.9 years in groups 1 and 2 respectively. Cycle management - notably, the introduction of analogues of gonadotrophin releasing hormone and the preparation of sperm - has, however, improved considerably. Pregnancy was defined as a serum β human chorionic gonadotrophin concentration >=25 IU/l within 16 days of the procedure, and its rate was expressed per transfer. Multiple pregnancy was assessed by ultrasonography in the first trimester.
The pregnancy rate fell from 23% in group 1 (flexible policy) to 16% in group 2 (restricted) (table). Twin pregnancies occurred in four out of 34 pregnancies (12%) in group 1 and in 10 out of 113 pregnancies (9%) in group 2. One triplet pregnancy occurred in group 1 (3%), and two such pregnancies occurred in group 2 (2%). There were no quadruplet or higher order pregnancies, regardless of the number of oocytes transferred.
Our results show that the chance of pregnancy after gamete intrafallopian transfer in women over 40 is reduced by restricting the maximum number of oocytes that may be transferred. The restrictions aim at reducing the incidence of multiple pregnancies, which result in higher morbidity and mortality. The risk of multiple pregnancy after gamete intrafallopian transfer is, however, inversely related to age.3 Because of their reduced fertility and the restrictions designed to protect against multiple pregnancy older women may be tempted to use oocytes donated by a young woman to maximise their chances of pregnancy, but, paradoxically, they will be at increased risk of multiple pregnancy. We have already warned of this risk in recipients of oocytes from young donors4 but we are unaware of any quadruplet or higher order pregnancy occurring in a woman aged 40 or older after natural conception or assisted conception in which the woman's own oocytes have been used.
Multiple pregnancy in older women after transfer of a flexible number of oocytes (12% twins and 3% triplets in this study) should be compared with rates accepted after transfer of the present maximum of three embryos in all women having in vitro fertilisation (24.5% twins and 4.6% triplets).5 We believe that more oocytes should be allowed to be transferred in older women having gamete intrafallopian transfer as their risk of having twins or triplets is low, with little risk of higher order pregnancy.
This study was supported by Life-Force Research.