Significance of meconium-stained amniotic fluid in term cesarean sections indicated by suspected fetal distress

Objectives To investigate the clinical significance of degreeⅢ meconium-stained amniotic fluid in term pregnancy. Methods Data of 857 full-term gravidas underwent cesarean section for suspected fetal distress in Peking University First Hospital from October 1, 2012 to September 30, 2014 were retrospectively analyzed. All patients were divided into three groups according to the diagnosis of suspected fetal distress: meconium-stained amniotic fluid group (Group 1, n=172), fetal heart abnormality group (Group 2, n=623) and meconium-stained amniotic fluid in combination with fetal heart abnormality group (Group 3, n=62). General information and fetal prognosis of the three groups were analyzed. Factors that might affect the prognosis of newborns were analyzed between the infants with or without acidosis, asphyxia or aspiration pneumonia. Analysis of variance, independent-samples t test, Chi-square test and rank-sum test were used as statistical methods. Results There were no significant differences in maternal age, gestational age at delivery, parity, nuchal cord loop(s), pH value of umbilical arterial blood and gender of newborns among the three groups (all P>0.05). The neonatal Apgar score, neonatal asphyxia rate and rate of admitting into pediatric ward within 24 hours after birth in Group 1 were similar to those of Group 2 and 3 [1 min Apgar score: 9.9±0.7 vs 9.8±0.7 and 9.8±0.7, F=0.322; 5 min Apgar score: 10.0±0.3 vs 10.0±0.2 and 10.0±0.0, F=0.517; neonatal asphyxia rate: 1.7% (3/172) vs 2.1% (13/623) and 1.6% (1/62), χ2=0.129; rate of admitting into pediatric ward: 16.3% (28/172) vs 14.3% (89/623) and 11.3% (7/62), χ2=0.978] (all P>0.05). The incidence of neonatal aspiration pneumonia in Group 1 was higher than that of Group 2 and 3 [4.7% (8/172) vs 3.2% (2/62) and 1.0% (6/623)], but the differences had no statistical significance (F=10.680, P=0.050). Conclusions Both degreeⅢ meconium-stained amniotic fluid and abnormal fetal heart rate have the same indicating significance and should be treated actively to lower the risk of poor prognosis of the newborns. Key words: Fetal distress; Cesarean section; Meconium aspiration syndrome; Prognosis