“Tight” nuchal cord is an uncommon but important aetiology of “idiopathic” polyhydramnios: a review study

ABSTRACT

The primary source of elimination of amniotic fluid is through foetal swallowing. Therefore, any condition that interferes with foetal swallowing, e.g., nuchal cord, can cause polyhydramnios.
This research is done over about 1 year duration in three obstetric hospitals. The participants in the research were 1,000 pregnant women with polyhydramnios in the third trimester of pregnancy. A search for the cause of polyhydramnios is done including ultrasound of foetus with a screen for nuchal cord by colour Doppler ultrasound study of the foetal neck, which when present, these foetuses are followed until delivery to confirm the tightness of the cord and also to exclude other potential causes of polyhydramnios.
The survey for the causes of polyhydramnios reveals that 4.1% of the idiopathic cases of polyhydramnios was due to tight nuchal cord, i.e., 1.2% of the total cases, whereas loose nuchal cords which are found accidentally during the screen was actually did not cause polyhydramnios.