••• Chapter 18^ Amniotic Fluid^191
❍ What AFI is consistent with polyhydramnios?
25 cm, or greater than 95th percentile for a particular gestational age.
❍ What is one of the first clinical findings that might indicate a diagnosis of polyhydramnios?
Fundal height greater than dates.
❍ What is the differential diagnosis for polyhydramnios?
- Diabetes, gestational and insulin dependent.
- Congenital anomalies.
- Multiple gestation.
- Immune and nonimmune fetal hydrops.
- Idiopathic.
❍ What is the most likely etiology of polyhydramnios?
Idiopathic; accounts for 66% of all cases of polyhydramnios.
❍ What specific congenital anomalies are associated with polyhydramnios?
- Central nervous system anomalies (eg, anencephaly).
- Skeletal dysplasias (eg, achondroplasia).
- GI atresias (eg, esophageal, duodenal).
- Tracheoesophageal fistulas.
- Facial clefts.
- Neck masses (such as cystic hygroma) that may interfere with fetal swallowing.
- Cystic malformations of the lung.
- Diaphragmatic hernia.
❍ What five tests are included in the initial workup of a patient with polyhydramnios?
- Glucola screen.
- Antibody screen.
- Screen for maternal hemoglobinopathies.
- Maternal viral titers (eg, parvovirus).
- Targeted ultrasound.
❍ Does excess fetal urine production play a major role in polyhydramnios?
No.
❍ What percentage of patients with polyhydramnios in the second trimester have spontaneous resolution?
40% to 50% of cases.
❍ What obstetrical complications are associated with polyhydramnios?
- Maternal respiratory compromise.
- Preterm labor.
- Premature rupture of membranes.
- Fetal malposition.
- Umbilical cord prolapse and/or postpartum uterine atony (potentially leading to postpartum hemorrhage).