Polyhydramnios Flashcards
What is Polyhydramnios?
Too much amniotic fluid @ pregnancy
What is the numerical definition of Polyhydramnios?
Amniotic fluid index above 95% centile for GA
How does the volume of Amniotic fluid change throughout pregnancy? (3 points)
- 0-33 weeks: Increases steadily
- 33-38 weeks: Plateaus
- 38+ weeks: Declines
What is the volume of Amniotic fluid at term?
500ml
What is Amniotic fluid made up of? (3 things)
- Foetal urine output (mostly)
- Placenta contributions
- Foetal secretions
What is the pathophysiology of Polyhydramnios?
Problems w any of structures in Amniotic fluid pathway
What is the Amniotic fluid pathway? (5 steps)
- Foetus breathes + Swallows Amniotic fluid
- AF processed
- AF fills blader
- AF voided
- Cycle repeats
What are the causes of Polyhydramnios? (11 things)
- Idiopathic (60%)
- Swallowing abn (oesophageal atresia / CNS abn / muscular dystrophies)
- Duodenal atresia
- Anaemia
- Foetal hydrops
- Twin-to-Twin transfusion syndrome
- Increased lung secretions
- Chromosomal abn
- Maternal DM
- Maternal ingestion of lithium
- Macrosomia (bc big babies make more urine)
What investigation is Polyhydramnios diagnosed with?
US
What are the ways to measure AF using US to diagnose Polyhydramnios? (2 things)
- Amniotic Fluid Index (AFI) (more common)
- Maximum Pool Depth (MPD)
Apart from the Dx, why are examinations / investigations done for Polyhydramnios?
To find out the cause
What examination can you do for Polyhydramnios?
Palpate uterus to see if it feels tense
What can you check for in the US for Polyhydramnios? (3 things)
- Assess foetal size
- Assess foetal anatomy (to check for structural causes)
- Doppler (to detect foetal anaemia)
What other investigations can you do for Polyhydramnios?
- Maternal Glucose Tolerance Test (for maternal DM)
- Karyotyping (for chromosomal abn)
Is any Medical intervention routinely required for women with Polyhydramnios?
No