Avoiding multiple pregnancies: sailing uncharted seas

E.R. Hernandez

Clinica de Reproduccion Asistida `FIV-Madrid', C/Alvarez de Baena 4, 28006 Madrid, Spain. E-mail: ehernandezm{at}meditex.es

Abstract

Single embryo transfer is being proposed as the solution to avoid multiple pregnancies in IVF. Nevertheless, in my opinion, although this is the right solution, it is still not the correct one at the present time. Mainly, it is unfair to the majority of infertile couples and it will also severely limit the physician's capacity to resolve unfavourable IVF cases. Furthermore, current IVF technology is far from perfect and the impact of single embryo transfer needs to be evaluated in patients over 38 years of age, poor responders, and also in regard to blastocyst transfer and the development of pre-implantation genetic diagnosis.

All caring professionals share with their patients the pain and inconvenience caused by any secondary effects of medical practices. One of these medical practices is the decision to transfer >2–3 embryos in IVF as a means of increasing pregnancy rates. Approximately 30% of the patients will have multiple gestation (Scholz et al., 1999; Gerris and Van Royen, 2000Go). The serious complications of multiple pregnancies for the mother and baby have been clearly stated in this debate (Scholz et al., 1999; Hazekamp et al., 2000Go; Olivennes, 2000Go) and should be a reminder to all the physicians involved in assisted reproductive transfer of our obligation to follow the guidelines set by the scientific societies in this regard (ASRM, RCOG; Templeton, 2000).

A simple solution to multiple IVF pregnancy is that of limiting the number of embryos transferred to one, which has been agreed as `the way to go' by many practitioners (Gerris and Van Royen, 2000Go; Hazekamp et al., 2000Go; Pennings, 2000Go; Templeton, 2000Go). Nevertheless, in my opinion, although this is the right solution, it is still not the correct one at the present time: mainly, it is unfair to the majority of infertile couples, but it will also severely limit the physician's capacity to resolve unfavourable IVF cases—and current IVF technology is far from perfect. Furthermore, it seems to me that before we encourage the health authorities (Templeton, 2000Go; Pennings, 2000Go) to adopt the single embryo transfer policy, the impact of such a restrictive regulation needs to be evaluated in patients over 38, in poor responders, etc., and also in regard to blastocyst transfer and the development of pre-implantation genetic diagnosis.

I am not questioning the prescribed solution (transfer one embryo), but the generalization of the rationale to all types of infertilities and to all infertile couples. For example, when two good embryos are transferred (to avoid triplets) the pregnancy rates will be approximately 30–40%, but if one embryo is transferred the rates decrease significantly to 14% (Edwards et al., 1996Go; Gerris and Van Royen, 2000Go). Given that of all IVF-derived pregnancies, ~30% will result in a twin gestation, it is unfair for the other 70% of couples to have their expectation of pregnancy decreased dramatically (from 30 to 14%) if one embryo is placed at a time (not to mention the dramatic consequences for a woman over 38). Furthermore, this strategy (single embryo transfer) will not only decrease the woman's probability of pregnancy but will generate a substantial increase in the final cost of IVF. For example, if in any given gonadotrophin-stimulated cycle (in a patient <35 years), one single embryo is transferred and 7–9 embryos remain frozen, it is easy to estimate the number of times (at least four or five) the couple will need to visit the clinic (for ultrasound, blood tests, laboratory work, etc.) to control endometrium proliferation and only have a single embryo with a <14% possibility of implantation. Thus, not only will the bills grow but also the stress, depression, anger, frustration, shame, etc. that can even lead to divorce (Mcnaugton-Cassill et al., 2000) that every unsuccessful thaw procedure and menstruation generates. When a couple is looking to their physician for answers, on what grounds can the policy of `one at the time' be sustained when our actual understanding of most of the steps of IVF (freezing, culture media, embryo development, to mention only a few) is so limited? It seems to me that our patients will never share our idea that solving one problem, multiple pregnancy, while generating another, is best.

However, if the whole idea is to avoid multiple gestation by transferring one embryo at a time, why not do it in a natural cycle? At least (and at the present time with similar pregnancy rates, 14%) the couple will save on medication and freezing procedures and the endometrium will (theoretically) be more receptive (Daya et al., 1995Go; Edwards et al., 1996Go; Rongieres-Bertrand et al., 1999Go).

Unfortunately, the bases for a successful SET (let's say pregnancy rates >20%) are not presently on our side, although some have already been written in the history of IVF. Many of us will remember the day the press announced the first human conceived by IVF as long as we live. As in most relevant advances for the human race, years of silent research and work were needed until finally the right embryo and a receptive endometrium coincided. This trinity holds the clues to avoid multiple pregnancy and the universalization of single embryo transfer. Years of research to improve current IVF technology, time to decipher which blastocyst will develop properly and to understand the nature of endometrial receptivity may one day lead to the ideal situation: one follicle, one embryo, one baby born. While we chart the course to this ideal situation, the best interest of the mother and her child will be protected by following society's guidelines and reaching a consensus with our patients.

References

Edwards, R.G., Lobo, R. and Bouchard, P. (1996) Time to revolutionize ovarian stimulation. Hum. Reprod., 11, 917–919 .[ISI][Medline]

Daya, S., Gunby, J., Hughes, E.G. et al. (1995) Natural cycles for IVF: cost effectiveness analysis and factors influencing outcome. Hum. Reprod., 10, 1719–1724.[Abstract]

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Hazekamp, J., Bergh, C., Wennerholm, U-B. et al. (2000) Avoiding multiple pregnancies: consideration of new strategies. Hum. Reprod., 15, 1217–1219.[Abstract/Free Full Text]

Mcnaughton-Cassill, M.E., Bostwick, M., Vanscoy, S.E. et al. (2000) Development of brief stress management support groups for couples undergoing IVF treatment. Fertil. Steril., 74, 87–93.[ISI][Medline]

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Pennings, G. (2000) Multiple pregnancies: a test case for the moral quality of medically assisted reproduction. Hum. Reprod., 15, 2466–2469.[Abstract/Free Full Text]

Rongieres-Bertrand, C., Olivennes, F., Righini, C. et al. (1999). Revival of the natural cycles in IVF with the use of a new GnRH antagonist (Cetrorelix): a pilot study with minimal stimulation. Hum. Reprod., 14, 683–688.[Abstract/Free Full Text]

Scholtz, T., Bartholomaus, S., Grimmer I. et al. (1999) Problems of multiple births after ART: medical, psychological, social and financial aspects. Hum. Reprod., 14, 2932–2937.[Free Full Text]

Templeton, A. (2000) Replace as many embryos as you like – one at a time. Hum. Reprod., 15, 1662.[Free Full Text]





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