Large for Dates Flashcards
Give 5 potential reasons why a baby may be LFD.
- Wrong dates.
- Fetal macrosomia.
- Polyhydramnios.
- Diabetes.
- Multiple pregnancy.
What may cause a woman to be a ‘late booker’?
- Concealed pregnancy.
- Vulnerable woman.
- Booked abroad.
What does foetal macrosomnia essentially mean?
‘Big baby.’
How is foetal macrosomnia diagnosed?
Using USS – if EFW (estimated fetal weight) is >90th centile.
+
Generic population-based and customised growth charts (ethnicity, BMI, parity).
What risks are associated with foetal macrosomnia?
- Clinician and maternal anxiety.
- Labour dystocia.
- Shoulder dystocia.
- PPH.
What is shoulder dystocia more common with?
Diabetes
How is shoulder dystocia managed?
- Exclude diabetes.
- Reassure.
- Conservative vs IOL vs C/S delivery.
What is Polyhydramnios?
Excess amniotic fluid
What are the potential causes of polyhydramnios?
- Maternal diabetes.
- Fetal anomaly.
- Monochorionic twin pregnancy.
- Hydrops fetalis – Rh isoimmunisation, infection (erythrovirus B19).
- Idiopathic.
List clincal features of polyhydramnios.
- Abdominal discomfort.
- Pre-labour rupture of membranes.
- Preterm labour.
- Cord prolapse.
Outline components of polyhydramnios seen clinically.
- Abdominal discomfort.
- Pre-labour rupture of membranes.
- Preterm labour.
- Cord prolapse. * Malpresentation.
- Tense shiny abdomen.
- Inability to feel fetal parts.
Outline what is seen on US in polyhydramnios.
- AFI (amniotic fluid index) >25.
* DVP (deepest vertical pocket) >8cm.
How is polyhydramnios diagnosed?
Clinical + US
Once polyhydramnios has been diagnosed, what further investigations should be carried out?
- OGTT.
- Serology – toxoplasmosis, CMV, parovirus.
- Antibody screen.
- USS – fetal survey – lips, stomach.
Outline the management of polyhydramnios.
- Patient information re complications.
- Serial USS to monitor growth, LV, presentation.
- IOL (induction of labour) by 40 weeks.
What is there a risk of in labour of someone with polyhydramnios?
- Cord prolapse.
- Preterm labour.
- PPH.
What type of exam must be done thoroughly in someone with polyhydramnios?
Neonatal exam
What is multiple pregnancy defined as?
The presence of more than 1 foetus e.g. twins, triplets etc.
What factors increase the risk of 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 meant by ‘monozygotic’?
The splitting of a single fertilised egg
What % of twin pregnancies are monozygotic?
30%
What is mean by dizygotic?
The fertilization of 2 ova by 2 spermatozoa
What % of twin pregnancies are dizygotic?
70%
What does ‘Chorionicity’ refer to?
Whether there is 1 or 2 placentas
Dizygous pregnancies are always what?
DCDA
Monozygous pregnancies can be what?
MCMA, MCDA, DCDA, conjoined
What does Chorionicity depend on?
The time of splitting of the fertilised ovum
What features – seen on ULTRASOUND – can help determine chorionicity?
- Shape of membrane and thickness of membrane – twin peak at 12 weeks.
- Foetal sex.
If splitting of the fertilized ovum occurs at each of the following days after fertilisation, what type of twin pregnancy results?
i) Day 0-3
ii) Day 4-7
iii) Day 8-14
iv) Day 15 onwards
- DCDA
- MCDA
- MCMA
- Conjoined twins
Why is it important to determine chorionicity?
Monochorionic/monozygous twins are at higher risk of pregnancy complications.
What sign is suggestive of dichorionic diamniotic twins?
Lambda
What sign is suggestive of monochorionic diamniotic twins?
T sign
Outline the symptoms of multiple pregnancy.
Exaggerated pregnancy sx e.g. excessive sickness/hyperemesis gravidarum.
What are the signs of multiple pregnancy (on ix)?
- High AFP.
- Large for dates uterus.
- Multiple foetal poles.
When and how is a multiple pregnancy confirmed?
USS at 12 weeks
Multiple pregnancies are associated with higher perinatal mortality. How much higher is this?
6 x’s higher than a single pregnancy
What foetal complications are associated with multiple pregnancy?
- Congenital anomalies
- IUD (single/both)
- Pre-term birth
- Growth restriction- both /discordant
- Cerebral Palsy-(twins 8X higher, triplets 47X higher)
- Twin to twin transfusion- oligohydramnios& polyhydramnios
What maternal complications are associated with multiple pregnancy?
- Hyperemesis Gravidarum
- Anaemia
- Pre-eclampsia
- Antepartum haemorrhage- abruption, placenta praevia
- Preterm Labour
- Caesarean section
What health professional leads a multiple pregnancy antenatal management?
Consultant
How often do monochorionic twins get a clinical appointment?
Every 2 weeks
How often do dichorionic twins have an antenatal appointment?
Every 4 weeks
What medications should women who are pregnant with twins be taking?
- Fe supplementation.
- Low dose aspirin.
- Folic acid.
How often do monochorionic twins get an US scan?
Every 2 weeks
How often do dichorionic twins get an US scan?
Every 4 weeks
When is the anomaly US scan done for twins?
18-20 weeks.
When do DCDA tend to deliver?
At 37-38 weeks
When do MCDA twins deliver?
At 36 weeks
What is the mode of delivery for triplets or more?
C section
In twins, if one is cephalic, what kind of delivery should you aim for?
Vaginal
Syntocinon (oxytocin) should be given when (in a multiple pregnancy birth)?
After twin 1
How long should intertwin delivery time be?
<30 mins
What are the 3 types of pre-gestational diabetes to consider?
- Type 1.
- Type 2.
- MODY.
What does the WHO define gestational diabetes as?
Carbohydrate intolerance resulting in hyperglycaemia of variable severity with onset or first recognition during pregnancy.
What do complications of diabetes in pregnancy all relate to?
Poor control
What complication are specific to pre-existing diabetes?
- Congenital anomalies – related to high HBA1C at booking.
- Miscarriage.
- Intra-uterine death.
What complications are specific to pre-existing and gestational diabetes?
- Pre-eclampsia.
- Polyhydramnios.
- Macrosomia.
- Shoulder dystocia.
- Neonatal hypoglycaemia.
Ideally, what should pre-pregnancy counselling in type 1 and type 2 diabetes cover(5)?
- HBA1C Monitoring- avoid pregnancy if HBA1C very high
- Stop any embryopathic medication eg ACE inhibitors, cholesterol lowering agents
- High Dose Folic Acid 5mg (3 months before conception to 12 weeks of pregnancy)
- Advice about diabetes
- Contraception
What 2 things should a woman with diabetes be prescribed in a diabetic antenatal clinic?
- Folic acid - 5mg
* Low dose Aspirin
When is the foetal anomaly scan done in diabetes?
18 weeks
Why should women with diabetes have regular eye scans?
To screen for retinopathy
How often should pregnancy diabetic women get growth scans?
Growth scans 4 weekly from 28 weeks
There is an __________ incidence of gestational DM
INCREASING
Outline the risk factors for gestational DM.
- Previous GDM
- Obesity BMI 30 or more
- FH: 1st degree relative
- Ethnic variation: South Asia (India / Pakistan/ Bangladesh), Middle Eastern, Black Caribbean
- Previous big baby
- Polyhydramnios
- Big baby – AC / EFW on USS
- Glycosuria (1+ on >1 occasion or >= 2+ on one occasion)
Pregnancy is diabetogenic
TRUE
What is the effect of placental hormones in gestational DM?
They can contribute to a relative insulin deficiency/insulin resistance.
What are the potential consequences of placenta hormones in GDM?
- Overgrowth of insulin sensitive tissues and macrosomia.
- Hypoxaemic state in utero.
- Short term metabolic complications.
- Fetal metabolic reprogramming leading to increase long term risk of obesity, insulin resistance and diabetes.
If a woman has had previous GDM, what should be done?
- BG monitoring.
or - OGTT 1st trimester – repeat at 24-28weeks if normal.
When should an OGTT be done in someone with previous GDM?
24-28 weeks
How is the OGTT carried out during pregnancy?
Venous FBS - 75g glucose - 2hr venous glucose.
What are the diagnostic results of the OGTT for GDM?
Fasting >=5.1mmol/l.
2 hour >=8.5mmol/l.
What fasting BG should be aimed for in GDM?
3.5-5.9mmol/l.
What 1hr BG should be aimed for in GDM?
<7.8mmol/l.
How often should blood glucose be taken in someone with GDM?
Minimum 4 times a day- premeals (sometimes 1 hr postmeal ) and before bed.
When should hypoglycaemic agents be considered in someone with GDM?
- diet and exercise fail to maintain targets
* macrosomia on ultrasoun
What are the potential advantages of oral hypoglycaemic agents?
- Avoidance of hypoglycaemia associated with insulin.
- Less weight gain.
- Less ‘education’ required to ensure safe/ effective administration.
Does insulin cross the placenta?
NO
What is there a risk of with insulin tx?
Hypoglycaemia
In a mother with pre-gestational diabetes, when should the baby be delivered?
38 weeks onwards, but earlier if there are complications
In a mother with GDM, when should the baby be delivered if on insulin?
38 weeks
In a mother with GDM, when should the baby be delivered if on metformin?
39-40 weeks
In a mother with GDM, when should the baby be delivered if managed with diet alone?
40-41 weeks
In a mother with GDM, when should the baby be delivered if fetal macrosomia/IUGR/PET?
Earlier delivery
If EFW >4.5kg, what should the mode of delivery be?
C -section
What is the mode of delivery in a diabetic mother?
Whatever the mother wants
What is the risk of future development of T2DM in someone with GDM?
70%
What are the main risk factors for the development of T2DM post-natal?
- Obesity
- Use of insulin during pregnancy
- Fasting glucose levels from OGTT in pregnancy
- IGT post-partum
- Ethnic group
When should FBS (fasting blood sugar) be checked post-natal??
6-8 weeks
If picture of T2DM, what should be done?
OGTT at 6 weeks post-natal