TWINS AND MULTIPLE PREGNANCY

Buxton U3A 16th May 2014

Ann Clark and Marion Overton

Frequency of Births in England and Wales 2011

• MATERNITIES 716,040

• TWINS 11,330 1/63

• TRIPLETS 1721/4163 Almost 1/63² (1/3969)

• QUADRUPLETS OR MORE 31/238,680Almost

1/63³ (1/250,047)

Multiple Births statistics in the UK for 2012

•    England and Wales

Scotland Northern Ireland

UK Total

Total

Maternities 729,674 (excluding stillbirths)

57,419 25,269 812,362

All multiples

1,441 (including stillbirths

8741 377 12,692

Twins 11,228 876 371 12,466 1/65

Triplets 208 7 6 1/3508

( 1/65²

1/4225)

Quads and above+

5 Not listed Not listed 5 1/145935

Length of pregnancy Average birth weight

40 weeksSingletons 3.5kg

37 weeks Twins 2.5kg

34 weeks Triplets 1.8kg

32 weeks Quads 1.4kg

Mortality Rates England and Wales 2007 (deaths per 1000 births)

Stillbirth Perinatal (first week)

Infant (1 week to 1 year old)

All 5.2 7.7 4.7

Twins 11.2 23.3 19.9

Triplets 19.7 49.3 50.3

• Identical twins have a higher mortality rate because ⅔ share the same placenta and blood circulation

Signs of Multiple Pregnancy

• Pregnancy test

• Morning sickness

• Uterine size

• Ultrasound scan

• Palpation of foetal parts

• Heartbeat

Who has twins or more?

• Older Mums

• Fertility treatment –particularly In Vitro Fertilisation (IVF)

• Positive Family History (for Hyperovulation)

Are they identical?

• Identical –from one egg (monozygous or uniovular)

• Fraternal –from 2 eggs fertilised at the same time (polyzygous or binovular)

• This is the zygosity of multiple births, and still holds true, but

NICE Guidelines

• 2011 National Institute for Clinical Excellence published guidelines for Antenatal Care:

• Risks ..determined by chorionicity and not by zygosity

Chorion includes the placenta

Amnion is the gestational membrane (sac) round the baby

Triplets

• Trichorionic, triamniotic

• Dichorionic, triamniotic

• Dichorionic, diamniotic

• Monochorionic, triamniotic

• Monochorionic, diamniotic

• Monochorionic monoamniotic

Is sharing a placenta BAD news?

It may be:

1. Chromosomal/congenital abnormalities

2. Foetofoetal transfusions

3. Discordance in size

NICE Guidelines

• Refer to a Regional centre:– Major foetal abnormality– Shared placenta (monochorionic)– Foetofoetal transfusion– Discordant foetal growth

Scan at 11-14 weeks, then fortnightly from 16-24 weeks

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