SCAG (04/03) - Human Fertilisation & Embryology Authority

SCAG (04/03)03
HUMAN FERTILISATION & EMBRYOLOGY AUTHORITY
THE SCIENTIFIC AND CLINICAL ADVANCES GROUP
Multiple Births Leaflet
1. At the 2003 February Authority meeting there was enthusiasm for producing a leaflet that
highlighted the risks of multiple births to women undergoing IVF. Subsequently, Jane Denton
suggested that the HFEA could adapt the multiple births foundation leaflet with an
acknowledgement that the leaflet was produced with the help of the MBF.
Issues to consider
2. Members are asked to consider the leaflet produced by the Multiple Births Foundation with a
view to adapting this leaflet for HFEA use SCAG (04/03)03.
3. Members are asked to suggest any amendments.
4. Relevant papers attached:
Ozturk O and & Templeton A., In-vitro fertilization and risk of multiple pregnancy. Lancet Jan 19;359 (9302):232.
Koivurova S et al., Neonatal outcome and congenital malformations in children born after in-vitro fertilization. Human
Reprodcution Vol 17 No. 5 pp. 1391-1398, 2002.
Ericson et al., Hospital care utilisation of infants born after IVF. Human Reproduction Vol. 17, No. 4 pp 929-932, 2002
The Eshre Capri Workshop Group. Multiple gestation pregnancy. Human Repoduction Vol 15. no. 7 pp. 1856-1864,
2000.
Garel M et al., Psychologocal consequences of having triplets: a 4 year follow- up study. Fertility and Sterility 67, No. 6
June 1997.
Dunn A & Macfarlane A., Recent trends in the incidence of multiple births and associated mortality in England and
Wales. Archives of Disease in Childhood 75, F10-F19, 1996. (to follow).
HFEA Executive
April 2003
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Multiple Pregnancy
& Multiple Birth
Information for couples considering treatments for infertility which may
result in a multiple pregnancy
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Multiple Pregnancy & Multiple Birth
The possibility of having more than one baby at the same time is something every patient and her
partner should think about before undergoing fertility treatment. Patients should discuss with their
doctors both their chances of having a twin or triplet pregnancy and what the implications would be.
This leaflet aims to help couples with this discussion.
What is a multiple pregnancy?
A pregnancy where two or more fetuses develop at one time in the uterus is called a multiple
pregnancy. The diagnosis can be made from an ultrasound scan which can be performed as early as
six weeks after the woman's last period. After in vitro fertilisation (IVF) procedures, it is usual to have a
scan as soon as the pregnancy is confirmed. When drugs alone are used to stimulate the ovaries, an
early scan may not be offered routinely. If this is the case it is advisable for the woman to talk to her
doctor and request a scan as soon as possible.
What is a multiple birth?
A multiple birth is the term used when a multiple pregnancy actually results in the birth of two (or more)
babies.
How does a multiple pregnancy occur?
• A woman can naturally release more than one egg from her ovaries during her menstrual
cycle. If these eggs are fertilised they may all implant in the woman's uterus and thus result
in a multiple pregnancy with non-identical twins, otherwise known as dizygotic or fraternal
twins.
• A single fertilised egg can divide into two identical halves. This would result in identical
twins - or monozygotic twins, being derived from one fertilised egg or zygote.
• Higher order births (triplets or more) arise in similar ways and may all be non-identical, all
identical or a combination of both types.
Many multiple pregnancies nowadays are the result of the drugs used to stimulate the ovaries to
release several eggs. When such drugs are used, there is a greater risk of a multiple pregnancy
because more eggs become available to be fertilised.
Fertility treatment is widely available in the UK and twins, triplets and quads have become much more
common. Now approximately two-thirds of triplets and nearly all higher order births - quadruplets,
quintuplets etc - result from fertility treatment.
What is the likelihood of having a multiple pregnancy following fertility treatment?
The probability of having a multiple pregnancy is much greater when drugs are used to stimulate the
ovaries to produce more than one egg in a cycle. There is also a greater probability if more than one
embryo is transferred to the womb in IVF, if more than one egg is replaced in gamete intrafallopian
transfer (GIFT), or if drugs to stimulate the ovaries have been given before donor insemination (DI).
• National guidelines allow fertility clinics to replace a maximum of three embryos (as in IVF)
or three eggs (GIFT) and some have a policy of replacing only two embryos.
• Some patients ask for fewer than three embryos (or eggs) to be replaced so as to reduce
the chances of triplets.
• Remember that even a single embryo sometimes divides to give an identical pair in a set of
twins or triplets.
In 1994, for every 100 pregnancies after IVF treatment, 26 pregnancies had more than one fetus. For
all DI treatments this figure was almost 8 pregnancies out of every 100.
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In comparison, the spontaneous conception rate for multiple pregnancies, that is in couples who are not
receiving any infertility treatments, is less than one per hundred.
A doctor should always provide some estimates of the likelihood of a multiple pregnancy for his/her
particular patient. But it is also important to realise that not all multiple pregnancies actually result in
more than one baby as some embryos fail to grow even if they implant.
What problems are likely to arise in a multiple pregnancy?
Multiple pregnancy places a much greater physical strain on the mother than a pregnancy with a single
baby.
• The risk of a miscarriage is greater.
• Sometimes one fetus dies early in the pregnancy and is reabsorbed (the vanishing twin
syndrome).
• Complications (such as bleeding, or raised blood pressure) are more likely to occur
than in a single pregnancy and can arise earlier in the pregnancy.
Are the babies likely to be born early?
Most multiple pregnancies are delivered before full term, that is before 40 weeks gestation (and about
one third of twins will be delivered pre-term, that is before 37 weeks).
• The average length of pregnancy is 37 weeks for twins, 34 weeks for triplets and 32.5 weeks
for quads 1 .
• The majority of triplets and higher order pregnancies are delivered by caesarean section.
For twins the rate is also much higher than in single pregnancies.
What will the babies weigh?
The birthweight of twins and triplets is generally lower than that of singletons who have an average
weight of 3.5kg (about 7lbs). The average birthweight of a twin infant is 2.5kg (about 5lbs) and of a
triplet 1.8kg (about 3lbs) 1 .
Are these babies more likely to die?
Any preterm baby is more likely to die than one who is born at full-term, so twins and triplets are at a
much greater risk than singletons. In 1993 the Office for National Statistics recorded that triplets were
about 6 times (twins 3 times) more likely to be stillborn and 12 times (twins 5 times) more likely to die
than single babies in the first year of their life. The perinatal mortality rate (that is deaths before birth
and in the first week) in 1993 of twins was 36.7 (per 1000 live and still births) and 72.6 for triplets
compared with 8.1 for single babies 2 .
Are these babies more likely to have disabilities or other health problems?
Babies who are born very prematurely are also more likely to have complications which can lead to long
term problems in the functioning of their lungs or heart and, in particular, their brain. A recent study
showed that triplet pregnancies produced a child with cerebral palsy 47 times more often than a
singleton pregnancy. The rate for cerebral palsy in twins was 7.4 per 1000 births and for triplets 26.7
compared with 1.6 for singletons 3 .
What are the implications for a couple having a multiple birth?
The problems of caring for more than one baby can be considerable and include emotional as well as
practical and financial aspects.
• There are no additional state benefits for multiple births in the UK, yet the everyday costs of
bringing up twins (even more so, triplets and quads) are much greater not least because
clothes and equipment cannot be 'handed down'.
• The cost of nursery equipment, clothes, food and childcare is inevitably substantial.
• Many mothers who had hoped to return to work after the birth have found that the cost of
childcare for twins or more makes this financially unviable 4 .
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Many parents' own physical and sometimes mental health suffers as a result of caring for twins.
Depression is more common in mothers of twins and this, like other problems, can affect their
relationships with each other, the wider family or friends. This in turn can make caring for their children
even more difficult.
It is important that all these and other implications of a multiple pregnancy are given careful
consideration before embarking on infertility treatment. Although twins and triplets undoubtedly can
bring many joys, both parents need to be realistically prepared first for the possibility and then, if a
multiple pregnancy results, with adequate prenatal advice.
Fetal reduction
Where there is a multiple pregnancy usually of triplets or more, the doctor may suggest that patients
consider a fetal reduction, sometimes called selective or embryo (reduction). This entails the reduction
of one or more embryos in the early weeks of pregnancy so that two (or occasionally one) embryos are
left to develop normally. This procedure is done in order to give the remaining embryo(s) a better
chance to develop into healthy babies.
Fetal reduction is a difficult option both emotionally and ethically and couples will wish to discuss it
carefully with their consultant and others with appropriate experience. Couples may contact the
Multiple Births Foundation for a leaflet on the subject. Some members of staff are also ready to discuss
the options to help a couple come to the decision that seems right for them and to provide advice and
support for as long as requested.
References
1. Bryan EM, Twins and Higher Order Births. A Guide to their Nature and Nurture. Edward Arnold, 1992.
2. Office for National Statistics, Mortality Statistics: Childhood, Infant and Perinatal Series PH3 No27. Stationery
office, London 1996.
3. Petterson B, Nelson K, Henderson D, Watson L, et al (1993). Cerebral Palsy in births in Western Australia in
the 1980's, BMJ 307, 1239-43.
4. Botting B, Macfarlane AJ, Price FV, eds. Three, four and more: A study of triplet and higher order births,
London HMSO 1990.
Useful Sources of information and advice
Multiple Births Foundation
Hammersmith House, Level 4
Queen Charlotte's and Chelsea Hospital
Du Cane Road, London W12 0HS
Tel 0208 383 3519 Fax 0208 383 3041
Email mbf@hhnt.nhs.uk www.multiplebirths.org.uk
Twins and Multiple Births Association (Tamba)
2 The Willows, Gardner Road, Guildford, Surrey GU1 4PG
Tel 0870 770 3305 Fax 0870 770 3303
Email enquiries@tamba.org.uk www.tamba.org.uk
ISSUE (National Fertility Association)
509 Aldridge Road, Great Barr, Birmingham B44 8NA
Tel 0121 344 4414
CHILD
Charter House, 43 St Leonards Road, Bexhill-on-Sea, East Sussex TN40 1JA
Tel 01424 732361
Human Fertilisation and Embryology Authority
Paxton House, 30 Artillery Lane, London E1 7LS
Tel 0207 377 5077
Further Reading
Booklet: 'The Prospect of Triplets or Quads' by Dr Frances Price. Available from the Multiple Births Foundation.
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Book: 'Infertility: New Choices, New Dilemmas' by Elizabeth Bryan and Ronald Higgins. Penguin 1995.
Book: 'Three, four and more: A study of Triplet and Higher Order Births' by Beverley Botting, Alison Macfarlane
and Frances Price. HMSO 1990.
The MBF is grateful to Manchester Fertility Services Research and Educational Trust for its financial support.
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