Large for Dates Flashcards
What is large for dates?
Symphyseal- fundal height > 2cm for gestational age
What is the aetiology of large for dates?
- Wrong dates
- foetal macrosomia
- polyhydramnios
- diabetes
- multiple pregnancy
What can cause wrong dates?
- late booker
- concealed pregnancy
- vulnerable women
- transfer of care: booked abroad
How is foetal macrosomia diagnosed?
- USS EFW >90th centile, AC> 97th centile
(estimated foetal weight and abdominal circumference)
What are the risks of foetal macrosomia?
Clinician and maternal anxiety
Labour dystocia
Shoulder dystocia- common with diabetes
Post-partum haemorrhage
What is the margin of error for EFW?
10%
What is the mangement of foetal macrosomia?
- exclude diabetes
- reassure
- conservative vs IOL vs C/S delivery
What is NICE’s suggestion on macrosomic babies and IOL
In the absence of any other indications, induction of labour should not be carried out simply because a healthcare professional suspects a baby is large for gestational age (macrosomic).
What is polyhydromnios?
Excess amniotic fluid
AFI >25cm
Deepest pool > 8cm
What is aetiology of polyhydramnios?
- maternal
- diabetes
- foetal
- anomaly- GI atresia, cardiac, tumours
- monochorionic twin pregnancy
- hydrops fetalis- Rh isoimmunisation
- viral infection (erythrovirus B19, toxoplasmosis, CMV)
- idiopathic
What are the symptoms of polyhydramnios?
Abdominal discomfort
Pre-labour rupture of membranes
Preterm labour
Cord Prolapse
What are the signs of polyhydramnios?
LFD
Malpresentation
Tense, shiny abdomen
Inability to feel foetal parts
How is polyhydramnios diagnosed?
Ultrasound Confirmation
- AFI >25
- DVP >8cm
What investigations should be done if polyhydramnios is diagnosed?
- OGTT
- Serology- toxoplasmosis, CMV, parvovirus
- antibody screen
- USS- foetal survey; lips, stomach
What is the management of polyhydramnios?
Patient information- complications
Serial USS- growth, LV, presentation
IOL by 40 weeks
What is the definition of multiple pregnancy and high order births?
Presence of more than one foetus
What is the incidence of spontaenous twins and spontaenous triplets?
1: 80
1: 10,000
What are the risk factors for multiple pregnancy?
- Assisted conception- clomid, IVF ( UK limits to 2 embryos)
- Race- African
- Geography
- Europe 6-9/1000 deliveries
- Nigeria 40-50/1000 ( 1 in 25)deliveries
- Japan & China 2/1000 ( 1 in 500) deliveries
- Family History
- Increased maternal age
- Increased Parity
- Tall women> short women
What is zygosity?
Monozygosity: splitting of a single fertilised egg (30%)
Dizygotic: fertilisation of 2 ova by 2 spermatozoa (70%)
What is chorionicity?
- 1 placenta/2 placentas
- dizygous- always dichorionic diamniotic (DCDA)
- monozygous- monochorionic monoamniotic (MCMA), monochorionic diamniotic (MCDA), dichorionic diamniotic (DCDA), conjoined; depends on time of splitting of fertilised ovum
How is chorionicity determined?
- Via ultrasound
- The shape of membrane and thickness of membrane
- twin peak at 11-13+6 weeks (CRL 45-84mm)
- placental masses, appearance of membrane attachment & foetal membrane thickness (lambda sign)
- fetal sex
- The shape of membrane and thickness of membrane
Why is determining chorionicity important?
Monochorionic/monozygous twins are at higher risk of pregnancy complications
What are the symptoms of multiple pregnancy?
Exaggerated pregnancy symptoms e.g. excessive sickness/HG
What are the signs of multiple pregnancy?
High AFP
Large for dates uterus
Multiple foetal poles
When can USS confirm multiple pregnancy?
at 12 weeks
What are the complications of multiple pregnancy
- higher perinatal mortality (6X higher than singleton pregnancy)
- foetal
- congenital anomalies
- IUD
- pre-term birth
- growth restriction- both/discordant
- cerebral palsy- twins 8X higher, triplets 47X higher
- twin to twin transfusion- oligohydramnios & polyhydramnios
What are the maternal complications of multiple pregnancy?
- Hyperemesis Gravidarum
- Anaemia
- Pre-eclampsia
- Antepartum haemorrhage- abruption, placenta praevia
- Preterm Labour
- Caesarean section
monochorionic twins need clinic appointments every _ weeks, dichorionic twins need clinic appointments every _ weeks
monochorionic twins need clinic appointments every 2 weeks, dichorionic twins need clinic appointments every 4 weeks