Relationship between meconium staining and amniotic fluid volume in term pregnancies

Objective: Our purpose was to evaluate the relationship between meconium-stained amniotic fluid (MEC-AF) and amniotic fluid volume (AFV) and their impact on the risk of cesarean delivery for fetal indications in term pregnancies. Methods: 1,655 live-born singleton gestations delivering at greater than or equal to37 weeks within 7 days of sonographic assessment of the amniotic fluid index (AFI) were studied. AFI was categorized as: oligohydramnios (less than or equal to5.0 cm); decreased (5.1-8.0 cm); normal (8.1-18.0 cm); increased (18.1-23.9 cm), and polyhydramnios (greater than or equal to24.0 cm). Frequencies of MEC-AF for each AFV category were stratified by gestational age (GA) and rates of cesarean delivery for fetal indications compared between patients with clear amniotic fluid and those with MEC-AF. Stepwise logistic regression analyses were performed for determinants of MEC-AF and the need for cesarean delivery for fetal indications. Results: The frequency of MEC-AF at birth in term pregnancies was not related to AFV: oligohydramnios (16.7%); decreased (16.7%); normal (20.1%); increased (24.4%), and polyhydramnios (22.1%). The only factor associated with the occurrence of MEC-AF was increasing GA at delivery (p<0.01). Both MEC-AF (p<0.02) and decreasing neonatal ponderal index (p<0.02) were independently associated with cesarean delivery for fetal distress. Conclusions: MEC-AF does not appear to be related to AFV in term pregnancies, and its presence increases the risk of cesarean delivery for fetal distress independent of AFV and neonatal ponderal index. Copyright (C) 2002 S. Karger AG, Basel.