Download Large for dates babies and polyhydramnios

Patient Information Service
Women and children’s business unit
Large for dates babies
and polyhydramnios
What does large for dates mean?
From approximately 28 weeks of pregnancy your midwife will
regularly measure the size of your tummy to monitor your baby’s
growth. A tape measure is placed at the top of your uterus and
measured to your pubic bone. This measurement is performed in
centimetres. If the measurement is two centimetres greater than
your dates the midwife will request a scan to check the growth
of the baby and fluid around the baby.
Scan findings
The scan may confirm that baby’s estimated weight is above
the 95th centile, however, it should also be acknowledged that
ultrasound scans are only accurate to within ten per cent.
However, the scan may show that your baby’s estimated weight
is not above the 95th centile and the reason you were measured
as large is that there is extra ‘water’ (liquor) around your baby.
This is known as polyhydramnios and occurs in less than one per
cent of pregnancies.
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What tests will be offered if my baby is above
95th centile or I have polyhydramnios?
Gestational diabetes could be the cause in either case.
You will be offered either a Glucose Tolerance Test (GTT) or
Home Blood Glucose Monitoring (HBGM) depending on how
many weeks pregnant you are.
If any result is suggestive of gestational diabetes we will offer a
referral to the diabetic specialist midwife who will advise you on
diet and blood sugar monitoring. A consultant appointment will
also be arranged and plans for the remainder of your pregnancy
and for delivery will be discussed with you.
Above the 95th centile – will I be able to have a
normal delivery?
If your baby has been identified as large for dates you will be
offered an appointment with a consultant obstetrician. The
current recommendations are that elective caesarean section is
only recommended if the baby’s weight is estimated to be above
5kg. Early induction of labour is also not advised solely for a
large baby as this can increase your risk of needing a caesarean
section and associated problems for you and your baby.
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The main anticipated concern is that your baby’s shoulders
may get stuck during delivery (after the head is born) and for
this reason a hospital birth in the central delivery suite will be
advised. Difficulty in delivering the shoulders is called ‘shoulder
dystocia’. Midwives and obstetricians will be alert for any signs
in order to anticipate difficulty with the shoulders. However this
happens very rarely and there are specific manoeuvres to help
release the shoulders. All midwives and obstetricians are trained
to deal with shoulder dystocia.
What does this mean for my baby?
If there is difficulty in delivering the baby’s shoulders, the
paediatrician (baby doctor) will be called to be present at
the birth.
Up to ten per cent of babies with a shoulder dystocia can
experience nerve damage (brachial plexus injury) which may
cause loss of movement to the baby’s arm. This is usually
temporary but for a small number of babies this may be
permanent. Other injuries can be sustained, such as fractures of
the baby’s arm. These fractures tend to heal without problems.
It is important to highlight that this can also happen at births
not complicated by shoulder dystocia.
Sadly, in very rare cases even when the best care is provided a
baby can suffer brain damage if there is a delay in delivering the
baby, and may even die.
3
Polyhydramnios – will I be able to have a
normal delivery?
Current recommendations do not support early induction of
labour or elective caesarean section.
If the polyhydramnios has been classified as moderate or severe
we will recommend that you deliver on the central delivery
suite, however if it is classified as mild and you are otherwise
low risk, you may be able to deliver on the midwifery led birth
unit after discussion with your midwife.
If you have polyhydramnios you have an increased chance of
your waters breaking early or going into labour early, both are
due to the overstretching of your uterus. We advise you to call
the hospital immediately if you think your waters have broken
or labour has started because there is an increased risk of the
umbilical cord slipping into the vagina if the baby’s head is not
engaged and this may affect your baby’s health if delivery is not
carried out immediately.
Due to the overstretching of the uterus there is an increased risk
of bleeding after the baby is born and you will be advised to
have an actively-managed third stage of labour (delivery of the
placenta) to reduce this risk. However if bleeding is excessive, a
blood transfusion may be required.
4
Polyhydramnios – what will this mean for
my baby?
If gestational diabetes has been ruled out as a cause for
polyhydramnios you may be offered screening for infection, and
additional scans and monitoring may be requested depending
on the level of fluid seen on scan. An individualised plan of care
will be made with you.
A paediatrician will check the baby soon after delivery and
before baby has his/her first feed. This is to rule out a rare
congenital problem where there is a blockage in the oesophagus
(swallowing tube) which causes polyhydramnios if baby cannot
swallow the amniotic fluid as would normally occur; hence the
fluid builds up during pregnancy. The paediatrician will gently
pass a tube down baby’s nose and into the stomach to ensure
there is no blockage.
Further reading
Royal College of Obstetricians and Gynaecologists (RCOG)
Shoulder Dystocia – Green-top Guideline No. 42 (2012)
Royal College of Obstetricians and Gynaecologists (RCOG)
Umbilical Cord Prolapse – Green-top guideline No. 50
(November 2014)
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Patient Information Service
If this leaflet does not answer all of your questions, or if you
have any other concerns please contact the antenatal triage on:
01702 385301.
www.southend.nhs.uk
For a translated, large print or audio tape version
of this document please contact:
Patient Advice & Liaison Service (PALS)
Southend University Hospital NHS Foundation Trust
Prittlewell Chase
Westcliff-on-Sea
Essex, SS0 0RY
Telephone: 01702 385333
Fax: 01702 508530
Email: [email protected]
Written by PIPMS
Reviewed by Andrea Harrington and
Deborah Edwards June 2016
Leaflet due for revision June 2018
Form No. SOU1580 Version 3