Polyhydramnios in singleton pregnancies- perinatal outcomes and management 2014 TOG Flashcards
What is the incidence of polyhydramnios
0.2-3.9%
PassMRCOG quote 1%
In what proportion is polyhydramnios unexplained?
50-60%
Normal singleton pregnancy, when does amitotic fluids increase/plataeu?
Increases until 33/40
Plateau 33-38 weeks
Decreases 38-42 weeks
Definition of polyhydarmios?
AFI >25 cm, DVP >8cm, >95 centile
Where is amniotic fluids produced?
-fetal urine production
-secretions from the respiratory tract
-oral secretions
Where is amniotic fluid removed?
Fetal swallowing
What are they dynamics across membranes?
-transfer across the placenta, umbilical cord, and fetal skin (intramembranous flow)
-across the fetal membranes (transmembranous flow).4
AFI cute offs for mild/moderate & severe
Mild 25-29.9cm
Moderate 30-34.9
Severe >35
Causes of polyhydramnios?
Maternal: uncontrolled DM, Rhesus isoimmunisation, Drug exposure (lithium - insipidus)
Fetal: Congenital malformation, chromosomal, infections, macrosomaia, fetal tumours
Placental - chorioangiomas, neuroblastoma
Unexplained
- Things that stop fetal swallowing - oestrophageal atresia, bowel obstruction, neurological.
What Ix for polyhydramnios
- OGTT/BM monitoring/HbA1c
- TORCH
- Check blood group status - ?antibodies
- Detailed USS
Cervical length - risk PTL
Risk of major anomaly with mild, moderate & severe polyhydramios?
Mild 1%
Moderate 2%
Severe 11% (10-20% aneuploidy)
When to refer to FMU?
suspected fetal anomaly
small for gestational age fetus
concerns with fetal movements
persistent or worsening polyhydramnios.
Risk of polyhydarmios
PTB
Unstable lie
Umbilical cord prolapse
Abruption
PPH
When is amniodrainage considered?
Resp compromise
Cervical shortening
Is isolated polyhydramnios a reason for IOL?
No, only if other obstetric complications.
Graph showing management of polyghydarmnios in singleton pregnancy
Flow diagram of unexplained polyhydramnios
