Diagnosis

The diagnosis of polyhydramnios is largely a clinical one. In cases of polyhydramnios the practitioner may find:

• symptomatology - in acute polyhydramnios the rapid build-up of pressure on surrounding structures may cause shortness of breath, oedema and oliguria
• a tense uterus which is large-for-dates
• difficulty in palpation of fetal parts
• difficulty in hearing fetal heart sounds
• the presence of a fluid thrill
• foetus has an unstable lie

An ultrasound must be preformed in all cases of suspected polyhydramnios to exclude multiple pregnancy or foetal abnormalities such as anencephaly.

The following may be mistaken for polyhydramnios:

• pregnancy with a coexisting large ovarian cyst
• concealed abruptio placentae