Archived: WMA Statement on Ethical Aspects of Embryonic Reduction

Adopted by the 47th WMA General Assembly Bali, Indonesia, September 1995
and rescinded at the WMA General Assembly, Pilanesberg, South Africa, 2006


The implementation of assisted reproduction (AR) techniques has resulted in a noticeable increase in the frequency of multiple birth pregnancies.

We recognize that in pregnancies involving more than 3 fetuses, problems of fetal mortality and retarded growth development linked to brain infirmity occur in more than 50% of the cases. We must also recognize the highly harmful effects of multiple births on the physical health of the mother and the possible psychological and practical consequences for both parents.

Concerning the in vitro fertilization techniques, it is desirable that preferably two and no more than three embryos be implanted at a time.

In cases involving medical stimulation of ovulation but not resorting to IVF techniques, the risk of multiple birth pregnancies exists and every effort must be made to minimize this risk by careful monitoring of the treatment, including the use of ultrasound and hormone determination.

In some cases, oocyte reductions can be indicated and should be strongly encouraged when they are medically possible.

If a pregnancy involving more than three fetuses should occur despite the above-mentioned precautions having been taken, the prognosis for the fetuses is so unfavorable that in order to improve the survival of the remaining embryos, procedures of a selective abortion of embryos might be considered. Such a possibility should be included in pre-treatment counselling.

However, because of the risk of complications that may arise and because it is indeed the elimination of a potential human being, the physician should avoid using this type of procedure simply to comply with the request of the parents who prefer for example only one child rather than two children from the pregnancy.


The WMA recommends:

  1. that whenever possible physicians take measures designed to prevent high multiple birth pregnancies; and
  2. that the parents be clearly informed of the reasons for embryonic reduction procedures and of the possible risks involved, and that the procedures not be done without their consent;
Embryonic Reduction