Middle East Fertility Society Journal, Vol. 10, No. 2, 2005, pp. 113-115
DEBATE
Prevention of multiple pregnancy in ART
Dr. Raja Al-Karaki, M.D.
Assisted Reproduction Technology Unit,
Al-Amal Maternity Hospital
Code Number: mf05021
Comment by:
|
Raja Al-Karaki, M.D.
|
|
Amman, Jordan
|
Introduction
The progress in assisted reproduction technologies over the last 25 years
has led to a tremendous success in obtaining pregnancies and deliveries in
different categories of infertility. The success of these technologies should
not be judged by only achieving a pregnancy but what has to be taken into
consideration is the safe obstetrical and neonatal outcomes with the objective
of the delivery of healthy baby which gives true reflection of a successful
practice.
The main factor in IVF programme increasing obstetrical and perinatal risks
is the high rate of multiple pregnancies. This is due to the widely practiced
policy of transferring more than one or two embryos in order to compensate
for the low implantation rate and achieve higher pregnancy rate (PR) which
may affect negatively the final outcome. It has been approved that multiple
gestation carry several risks for both the fetuses and the mother. Maternal
complications are mainly pregnancy induced hypertension, preterm labor, antepartum
hemorrhage and surgical delivery. Adverse neonatal outcomes involve preterm
birth, low weight and small for gestational age, all are major risk factors
for neurodevelopmental disorders (1).
Considering these unfavorable outcomes more attention has been paid though
out the world for reporting different parameters of IVF programme including
multiple gestations. In European registry the multiple pregnancy rate was
26.4 % (twin 24.4%, high order multiples 2%)(2) while it was 37.8% (twin
30.8%, high order multiples 7%) in USA data (3).In the Middle East, the first
IVF registry for the year 2000 (4) determined that 32.6% of IVF pregnancies
were multiples (twin 27.4%, high order multiples 5.2%). This significant
incidence of multiple gestation directed efforts especially by European countries
towards reducing the number of embryos transferred. The policy of transferring
only two embryos in some reports (5) avoided high order multiple pregnancies
but still having high twin PR. Therefore more trends shifted to elective
single embryo transfer (eSET) which was capable to decrease or eliminate
totally the risk of twinning without affecting the overall PR (6,7). Another
study (8) has shown that PR dropped significantly after SET but this was
the case when only a single embryo was available loosing the advantage of
embryo selection. Other policies tried to avoid multiples through extending
embryo culture to the blastocyst stage. Single blastocyst transfer proved
to be affective in eliminating multiple births while maintaining high PR
in a selected group of women (9).
Concerning the issue of multiple gestation associated with IVF in our area,
real attempts to solve the problem are lacking. This needs a deep insight
to establish new guidelines into clinical practice.
Tackling the problem of multiple gestations: Issues to be considered
Changing the policy of embryo transfer
Reducing the number of transferred embryos forms the main effective strategy
in minimizing multiple pregnancies in IVF. Although SET is becoming an accepted
procedure in certain countries, it maybe difficult to reach agreement in applying
this as a starting strategy due to physician concern to keep the stable PR.
In addition, in countries who adopted this policy, IVF treatment is covered
by the health care system while in the Middle East costs of IVF are paid by
the patients. Therefore, it would appear prudent to start transferring two
embryos to ensure that acceptable implantation and PR can be established before
introducing SET. To have the best effectiveness a proper patient selection
and embryo quality scoring should be considered. Double ET is to be applied
in favorable prognosis groups (Female age < 35 years, first two IVF trials,
previous success with IVF and good quality embryos). However under certain
circumstances, higher number of embryos for transfer is allowed. The ability
to avoid the most risky multiplicity (triplet or more) with maintaining the
PR and the expanded experience with practicing this trend will encourage the
physicians and assure patients, helping to broaden the scale for applying eSET
to eliminate the twinning rate. Another strategy in this regard is extending
embryo culture to blastocyst stage which is effective in identifying the most
viable embryos in a given cohort. The fact that the implantation rate with
use of top-scoring blastocyst is substantially higher than that achieved with
cleavage stage embryos (10) makes the introduction of single blastocyst transfer
a potentially viable solution in eliminating twins and preserving the high
PR. It is worth to notice that the availability of effective cryopreservation
system will offer the patients frozen-thawed embryo transfer opportunity which
increases the overall PR per initiated IVF cycle in single or double ET (11).
Multi fetal pregnancy reduction
Currently, many groups practice multifetal pregnancy reduction in pregnancies
with three or more fetuses in an effort to increase the likelihood of a
successful pregnancy. Embryo reductions, still carry 10% risk of miscarriage
(12) as well as some risks for the new born (13). Moreover this procedure
is psychologically and morally harmful for couples who so wanted children.
In fact, this can be avoided by limiting the number of transferred embryos.
The physician's responsibility
Multiple pregnancies in IVF is iatrogenic and it is the physician's responsibility
to minimize this undesirable outcome. The priority to avoid multiples should
be given over the increase in PRs as well as over multifetal reduction
policy to ensure the best possible outcome.
Patient Counseling
The emotional stress of infertility, the financial burdens and the lack
of knowledge on the risks of multiple gestations make a significant demand
among infertile patients for transferring higher number of embryos with
the sequalae of multiples. In view of these factors, couples often resist
discussion of multiple pregnancy issue during the psychological consultation
because they focus only on the goal of getting pregnant and minimize the
concern about the welfare of the mother and infant. Therefore, offering
guidance towards solving this concern with proper counseling to illustrate
the risk of multiples and their contribution to variant problems is essential.
The association of the policy of reducing embryo number for transfer with
successful outcome as well as its cost effectiveness compared with multiple
pregnancies should be stressed on.
Conclusion