Oligohydramnios, or decreased amniotic fluid, is associated with morbidities (cesarean delivery [CD] for nonreassuring fetal heart rate tracing [NR FHR], low Apgar score) and mortality, even among nonanomalous fetuses. Summation of the deepest pocket measurement in 4 quadrants, called the amniotic fluid index (AFI), or measuring the single deepest pocket (SDP) in any quadrant is used to sonographically assess amniotic fluid. The AFI should be abandoned in favor of SDP because metaanalysis of 5 randomized clinical trials (RCTs), with more than 3200 women, noted that use of AFI significantly increased the likelihood of being categorized as oligohydramnios, being induced and undergoing CD for NR FHR, without concomitant improvement in neonatal outcomes. Additionally, the substantial literature on biophysical profile (BPP) has significantly decreased the likelihood of neonatal mortality and of cerebral palsy using SDP, not AFI.

Before recommending delivery for oligohydramnios at 34 ^0/7 to 36 ^6/7 weeks, I acknowledge that there are no current American College of Obstetricians and Gynecologists (ACOG) practice bulletins on the topic and no RCTs. The rationales for delivery of singletons with intact membranes and oligohydramnios at these weeks are the following:

• 1
  

  After 34 weeks, pulmonary maturity is sufficient that corticosteroids need not be administered, regardless of whether the preterm delivery is spontaneous or indicated.

  
  
• 2
  

  The BPP protocol recommends delivery with oligohydramnios, even if the remainder of the score is 8 of 8.

  
  
• 3
  

  The ACOG practice bulletin on ultrasonography in pregnancy notes that oligohydramnios is a risk factor for perinatal mortality.

  
  
• 4
  

  The ACOG practice bulletin on intrauterine growth restriction (IUGR) acknowledges that with olighodhyramnios there is an increased risk of sudden death because of the vulnerability of the umbilical cord. We know that IUGR is unsuspected antenatally in at least half the case, if not more, because of vagaries of sonographic estimates of birthweight.

  
  
• 5
  

  Currently adverse outcome with expectant management of oligohydramnios is indefensible and a potential source of litigation. A survey of ACOG members noted that after neurological injury of newborn, stillbirth/neonatal death was the second leading cause of obstetric litigation.

In summary, it is recommended to deliver women with intact membranes and oligohydramnios at 34 ^0/7 to 36 ^6/7 weeks, unless an RCT concludes otherwise.