ABSTRACT
Amnioinfusion is a technique in which a crystalloid solution, usually normal saline, is instilled into the amniotic cavity to replace amniotic fluid, which may be absent or low. By the 16th week of gestation, the amniotic fluid volume is mainly regulated by the processes of fetal urination and fetal swallowing. The amniotic fluid environment is necessary for normal fetal growth and development, as evidenced by fetal lung hypoplasia and deformations in the case of Potter’s syndrome. Oligohydramnios predisposes to umbilical cord compression, which can lead to fetal hypoxia if resultant interference with blood flow is severe, repetitive, and prolonged. Ultrasound evaluation of the amniotic fluid includes the one largest vertical pocket and the amniotic fluid index (AFI). Amnioinfusion is generally classified according to the pregnancy status as antepartum or intrapartum. The procedure is performed either transcervically or transabdominally. Its purpose can be diagnostic, therapeutic, or prophylactic.
