Large for Dates Flashcards
what is considered large for dates
symphyseal fundal height > 2cm for gestational age
what is SFH
symphyseal gestational height
what can cause LFD (large for dates)
wrong dates fetal macrosomia (big baby) polydramnios diabetes (can cause macrosomia or polydramnios) multiple pregnancy
why might someone be a ‘late booker’ and have the wrong dates of conception
concealed pregnancy- fit, muscular or obese
vulnerable women- hesitant to / cant engage with healthcare
transfer of care- booked abroad
what classifies as fetal macrosomia
USS estimated fetal weight > 90th centile
abdo circumference > 97th centile
(on generic population charts or customised growth charts - BMI, ethnicity and parity are considered)
what are the risks of fetal macrosomia
clinician and maternal anxiety
labour dystocia (obstructed labour, aka cervical dystocia)
shoulder dystocia - more with diabetes
post partum haemorrhage
where are the smallest and biggest babies in the world
smallest- SE asia
biggest- caucasian UK
what is the formula for EFW
hadlock- considered HC, AC and FL
accuracy of USS depends on operator, maternal BMI (harder if higher), gestation (more accurate <38 weeks)
is the EFW from USS usually higher or lower than actual weight
higher
what is the management for macrosomia
exclude diabetes
reassure mother
conservative vs IOL vs CS
IN THE ABSENCE OF ANY OTHER INDICATIOS IOL SHOULD NOT BE CARRIED OUT SIMPLY BECAUSE OF MACROSOMIA
at what EF weight would you recommend a CS
more than 4.5 kg
what is polyhydramnios
excess amniotic fluid
what classifies as polyhydramnios
amniotic fluid index >25cm
deepest pool in ant pocket of cord free ares >8cm
what are the maternal causes of polyhydramnios
diabetes
what are the fetal causes of polyhydramnios
anomaly- GI atresia (congenital malformation of the bowel causing obstruction), cardiac abnormalities, tumours
monochorionic twin pregnancy
hydrops fetalis (accumulation of fluid in at least 2 fetal compartments)
viral infections (erythrovirus B19, toxoplasmosis, CMV)
idiopathic (2nd most common after diabetes)
what are the signs and symptoms of polyhydramnios
symptoms: abdo discomfort pre labour rupture of membranes preterm labour (due to overdistention of uterus) cord prolapse signs: LFD malpresentation tense shiny abdomen inability to feel fetal parts
how is polyhydramnios diagnosed
USS
AFI >25
DVP >8cm
what investigations for polyhydramnios
OGTT to exclude diabetes
serology - toxoplasmosis, CMV, parovirus
antibody screen (rhesus isoimmunisation can cause hydrops fetalis)
USS fetal survey - lips, stomach (ensure patent oesophagus and good swallowing mechanism)
what is the management for polyhydramnios
patient information (complications)
serial USS- growth, liquor volume (volume of amniotic fluid), presentation
IOL by 40 weeks
neonate exam
what are the risk of labour in polyhydramnios
malpresentation
cord prolapse
preterm labour
PPH
what classifies as pre term labour
before 37 weeks
how common are spontaneous twins
1:80
what puts you at risksof having a multiple pregnancy
assisted conception (in uk limit to 1 embryo) race - african (esp nigerian) FMHx increased maternal age increased parity tall women > short women
why is there higher rates of twins in africa
higher perinatal mortality rates
what are the types of zygosity
monozygotic- splitting of a single fertilised egg (30%)
dizygotic- fertilisation of 2 ova by 2 spermatozoa (70%)
what are the types of chorionicity
(1 placenta/ 2 placenta)
dizygous always DCDA (dichorionic)
monozygous twins can be MCMA, MCDA, DCDA or conjoined
what does chorionicity depend on
in dizygous twins always DCDA
in monozygous twins depends on splitting of fertilised ovum
what do DCDA, MCDA, MCMA stand for
Dichorionic diamniotic
monochorionic diamniotic
monochorionic monoamniotic
what does monochorionic mean
share placenta
what does monoamniotic mean
share amnionic sac- can have one or two placenta
cleavage into twins at days 0-3 will result in what
dichorionic diamniotic (DCDA)
cleavage into twins at days 4-7 will result in what
monochorionic diamniotic (MCDA)
cleavage into twins at days 8-14 will result in what
monochorionic monoamniotic (MCMA)
cleavage into twins after day 15 will result in what
conjoined twins
how is chorionicity determined
USS:
-shape and thickness of membrane (twin peak at 11-13.6 weeks (CRL 45-84 mm), placental masses, appearance of membrane thickness (lamba sign))
fetal sex- determines if dichorionic or not
what type of twins are at higher risk of pregnancy complications
monochorionic/ monozygous twins= MCMA
what type of twins will have the lamba sign on USS
dichorionic diamniotic
what forms the amnionic sac
chorion (outer) and amnion (inner)
what are the signs and symptoms of multiple pregnancies
exaggerated pregnancy symptoms (excess sickness/ hyperemesis gravidarum)
high AFP
large for dates uterus
multiple fetal poles
when can USS confirm multiple pregnancies
12 weeks
what is recommended if a patient has hyperemesis before first scan
USS to see if multiple pregnancy
what are the fetal complications of multiple pregnancies
higher perinatal mortality
congenital abnormalities (e.g. acardiac twin)
IUD (single/ both)
pre term birth
growth restriction (both/ discordant)
cerebral palsy (twins 8x higher, 47x higher in triplets)
twin to twin transfusion (oligohydramnios and polyhydramnios)
what are the maternal complications of multiple pregnancies
hyperemesis gravidarum anaemia pre eclampsia antepartum haemorrhage (abruption (placenta dislocates from uterus), placenta praevia) preterm labour caesarian section
what is the antenatal management for multiple pregnancies
MC- clinic every 2 weeks DC- clinic every 4 weeks maternal educations- preterm labour and risks, support (+ financial) consultant led care Fe supplementation- risk of anaemia low dose aspirin- reduce pre eclampsia folic acid USS MC 2 weekly from 16 weeks DC 4 weekly anomaly USS at 18-20 weeks
what extra scans do MC twins get
deep vertical pool
bladder and umbilical artery doppler (UAPI)
estimated fetal weight
what complications are seen in MC twins
single fetal death (affects other twin in utero too)
selective growth restriction
twin to twin transfusion syndrome (TTTS)
twin anaemia polycythaemia sequence (TAPS)
absence end diastolic velocity or reversed end diastolic velocity
what can cause TAPS
fetoscopic laser ablation for TTTS
what is twin to twin transfusion syndrome
imbalance in circulation between twins from shared placenta due to atery vein anastomoses
donor twin will be olihydramniotic (and will be pale and small- anaemic)
recipient twin will by polyhydramniotic (larger and red- polycythemic)
how is TTTS diagnosed
Oligohydramnios- polyhydramnios (Oly-Poly)
what are the complications os TTTS
mortality >90% with no Tx
neurological morbidity 37% and high in surviving twin if IUD
what is the treatment for TTTS
before 26/40 - fetoscopic laser ablation
> 26/40 amnioreduction/ septostomy
deliver 34-36/40
what are the complec multiple births
MCMA twins:
- risk for cord entanglement
- higher risk of fetal death
- always delivery by C section 32-34+o weeks
conjoined twins:
-MDT, specialised centres
trichorionic triplets/ MC or DC twins with sGR, TTTS, TAPS consider selective reduction
when should you aim to deliver twins
DCDA- 37-38 weeks
MCDA after 36+0 weeks WITH steroids
what mode of delivery for multiple pregnancies
MOTHERS choice
triplets or more rec CS
MCMA CS
twins if twin 1 cephalic aim for V, if twin 1 breech/ transverse C section
what needs to be done in a multiple pregnancy delivery
consultant led
epidural
fetal monitoring- USS and fetal scalp electrode
syntocinon after twin 1
USS to confirm presentation
intertwin delivery time <30 mins
risk of PPH- active 3rd stage- oxytocin infusion
what pre gestational diabetes types can you get
T1
T2
MODY
what is gestational diabetes
carbohydrate intolerance resulting in hyperglycaemia of variable severity with onset or first recognition during pregnancy (ends when pregnancy ends)
what complications are specific to pre existing diabetes in pregnancy
congenital abnormalities
miscarriage
IUD
worsening diabetic complications (retinopathy, nephropathy)
what should you ask all women with diabetes
about contraception and family planning- save more babies by seeing in pre pregnancy clinics
what pregnancy complications can you get in pre existing and gestational diabetes
pre eclampsia polyhydramnios macrosomia shoulder dystocia neonatal hypoglycaemia
what HBA1c level means you should avoid pregnancy
above 86mmol/mol (10%)
what is the HBa1c aim in pregnancy
48mmol/mol (6.5%)
what medication advice should you give diabetics pre pregnancy
Stop any embryopathic medication eg ACE inhibitors, cholesterol lowering agents
High Dose Folic Acid 5mg (3 months before conception to 12 weeks of pregnancy)
what extra tests for diabetic (T1 and 2) pregnancies
Fetal anomaly scan at 18-20 weeks Regular eye checks for retinopathy If nephropathy- refer renal team Consider continuous glucose monitoring (libra) Growth scans 4 weekly from 28 weeks
management for diabetic pregnancies (T1 and T2)
Folic Acid 5mg
Low Dose Aspirin from 12 weeks- until delivery
Hypoglycaemic Agents:
Insulin- MDI /Insulin pump
Metformin (Type 2)
Counsel about shoulder dystocia
Deliver at 38 weeks ( earlier if complications)
what are the risk factors for gestational diabetes
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
why is pregnancy diabetogenic
due to the hormones human placental lactogen and cortisol
placental hormones cause relative insulin deficiency and resistance
what are the consequence of gestational diabetes
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
what is the screening for GDM
Risk factors at booking
Previous GDM (recurrence risk >50%0= BG monitoring
or OGTT 1st Trimester- if normal repeat 24-28 weeks
OGTT 24-28 weeks (if just risk factors not previous GDM)
how is GDM diagnosed
OGTT:
venous fasting blood sugar taken
75g glucose solution taken orally
rest for two hours
2hr venous glucose
diagnostic values:
Fasting >=5.1 mmol/l
2 hour >=8.5 mmol/l
what is the general management for GDM
diet, body weight and exercise
Monitor for PET (pre-eclampsia)
Growth scans
Consider Hypoglycaemic agents (insulin or metformin) when
diet and exercise fail to maintain targets
macrosomia on ultrasound
care plan: Antenatal and intrapartum Targets for glycaemic control Fetal surveillance Post-natal care / review
what are the risk of GDM
macrosomia and neonatal hypoglycaemia Possibility of transient morbidity in the baby
Increased risk for the baby of obesity and diabetes in later life
Increased risk of type 2 diabetes for the mother (gestational)
what are the glycaemic targets for GDM
Minimum 4 times a day- premeals (sometimes 1 hr postmeal ) & before bed. Fasting 3.5 -5.5 mmol/l 1 hr <7.8mmol/l
what are the advantages of metformin over insulin in pregnancy
Avoidance of hypoglycaemia associated with insulin
Less weight gain
Less ‘education’ required to ensure safe / effective administration
does insulin treatment cross the placenta
no
when should you deliver babies with maternal pre gestational diabetes
38 weeks onwards
Earlier if complications
when should you delivery babies with maternal GDM
Insulin treatment 38-39 weeks
Metformin 39- 40 weeks
Diet alone 40 to 41 weeks
If fetal macrosomia/ IUGR/ PET earlier delivery
what are the risk factors for mothers develop T2DM after GDM postnatally
obesity use of insulin during pregnancy fasting glucose levels from OGTT in pregnancy IGT post partum ethnic group
when is FBS done postnatally after GDM
6-8 pn
what dose of folic acid for diabetic women
5mg (normal dose 400 micrograms)
