Objective: To determine the prevalence and clinical significance of meconium stained amniotic fluid (MSAF) in women with preterm delivery.
Study design: The study population consisted of consecutive patients who arrived with intact membranes and delivered preterm, singleton neonates at the Soroka Medical Center between 1 January 1985 and 31 December 1995. Only vertex presentation was included. Antepartum death was excluded from the study. Patients were classified according to the color of amniotic fluid into two groups: MSAF and clear amniotic fluid. Maternal puerperal complications were defined in our study as the presence of at least one of the next variables: clinical chorioamnionitis; major puerperal infection including endometritis, cesarean section or postpartum hemorrhage. Perinatal complications were defined in our study as: (1) intrapartum death (IPD) or postpartum death (PPD); (2) one or more of the following: 1-min Apgar score <3, 5-min Apgar score <7 or small for gestational age. Rates of perinatal complications were assessed at: (1) 24-27 weeks; (2) 28-31 weeks; (3) 32-36 weeks. Logistic regression was used to investigate the relationship of MSAF to perinatal complications and maternal morbidity in a multivariate model.
Results: During the study period, a total of 96 566 deliveries occurred in our institution and 4872 (5.0%) deliveries were preterm. Among the women delivering preterm meeting eligibility criteria, 276 (5.7%) women had intrapartum MSAF. A higher rate of IPD and PPD was observed only between 32 and 36 weeks' gestation in patients with MSAF in comparison with patients with clear amniotic fluid [6.1% (14/230) vs. 2.1% (85/4045), respectively, P=0.0001]. A statistically significant higher rate of perinatal complications was found between 28 and 31 weeks' gestation, and even a higher rate was noted between 32 and 36 weeks' gestation in the MSAF group in comparison with patients with clear amniotic fluid [51% (18/35) vs. 27.2% (93/341), respectively, P=0.003; 20% (46/230) vs. 9.8% (396/4045), respectively, P=0.0004].
Conclusions: (1) MSAF is an independent risk factor for perinatal complications in preterm deliveries (OR=1.73, CI: 1.057-2.43, P=0.001; OR=2.35, CI:1.34-4.12, P=0.002, respectively). (2) MSAF was not found to be an independent risk factor for maternal morbidity.