Large for Dates Pregnancy (Macrosomia, Polyhydramnios and Multiple Pregnancy) Flashcards
How is a foetus diagnosed as being large for dates?
Symphysial fundal height > 2cm greater than what would be expected for gestation / a foetus which is > 90th centile for symphysial fundal height/estimated foetal weight
What are the 5 main aetiologies of a large for dates baby?
Wrong estimated gestation date, foetal macrosomia, polyhydramnios, multiple pregnancy, diabetes
Why do wrong estimated gestational dates most commonly occur?
Due to late bookers, because they forget when they really had their last period
What are some causes of being a late booker?
Concealed pregnancy, vulnerable woman, transfer of care
What does foetal macrosomia mean?
It is the medical term for being a big baby - an US shows an estimated foetal weight > 90th centile on both generalised and personalised growth charts
What are some risks associated with foetal macrosomia?
Labour dystocia, shoulder dystocia, PPH
What is labour dystocia?
The uterus is contracting normally but the baby does not exit the pelvis because it is physically blocked
What is shoulder dystocia?
The baby’s head has been delivered but one of its shoulders is stuck behind the pubic bone
Shoulder dystocia is more common in mothers with what?
Diabetes
If a baby has foetal macrosomia, what must be excluded?
Maternal diabetes
What are some management options for foetal macrosomia?
Conservative, IOL, C-section delivery (decreases risk of shoulder dystocia)
What is the definition of polyhydramnios?
Excess amniotic fluid
The volume of amniotic fluid is controlled by what? How does this cause polyhydramnios?
Swallowing and urination - any imbalance in this intake and output can cause polyhydramnios
How is polyhydramnios diagnosed?
Ultrasound scan showing deepest pool > 8cm / amniotic fluid index > 25cm
What is the maternal aetiology of polyhydramnios?
Diabetes
What are some foetal aetiologies of polyhydramnios?
Structural anomalies, monochorionic twin pregnancy, viral infections, hydrops foetalis
What is hydrops foetalis (a cause of polyhydramnios)? What are some things that can cause it?
Accumulation of fluid in at least 2 foetal compartments, is usually caused by anaemia but also be Rh disease
Can polyhydramnios occcur idiopathically?
Yes
TORCH viral infections in the foetus can predispose to polyhydramnios. What are these?
Toxoplasmosis, other (VZV, syphilis, parvovirus), rubella, cytomegalovirus, herpes
What are some symptoms of polyhydramnios?
Abdominal discomfort and shortness of breath
What are some complications that may arise as a result of polyhydramnios?
P-PROM, preterm labour, cord prolapse, malpresentation, PPH
What are 4 clinical signs of polyhydramnios?
Symphysial-fundal height > expected, malpresentation, tense shiny abdomen, inability to feel foetal parts
What are some investigations you could do to investigate an underlying cause of polyhydramnios?
Oral glucose tolerance test, serology for viruses, antibody screen and Hb, US for foetal anomaly
If a woman has polyhydramnios and a chromosomal abnormality is suspected as the cause, what investigation should be performed?
Amniocentesis
How should polyhydramnios be managed?
Patient information and discuss possible labour complications, serial US scans to monitor growth and presentation, induction of labour by 40 weeks
How common is a spontaneous a) twin and b) triplet pregnancy?
a) 1/80 b) 1/10,000