Thick Meconium-stained Amniotic Fluid Research Articles

Can Asphyxiated Infants at Risk for Neonatal Seizures Be Rapidly Identified by Current High-risk Markers?

Markers currently used to identify infants at highest risk for perinatal hypoxic-ischemic cerebral injury are insensitive in predicting the subsequent occurrence of neonatal seizures and/or neurodevelopmental sequelae, ie, cerebral palsy. To facilitate therapeutic strategies, early identification of the infant at highest risk for developing seizures secondary to hypoxia ischemia or asphyxia is critical, particularly if novel but potentially toxic therapies currently under experimental investigation become available for clinical use. Ninety-six inborn term infants considered at high risk for having neonatal seizures secondary to hypoxia ischemia or asphyxia and admitted to the neonatal intensive care unit directly after labor and delivery were prospectively evaluated. Markers of high risk included the presence of moderate to thick meconium-stained amniotic fluid (MSAF), fetal heart rate (FHRT) abnormalities abruptio placentae, intubation and positive pressure ventilation in the delivery room (DR), chest compressions and epinephrine administration as part of resuscitation, a 5-minute Apgar score of 5 or less, umbilical cord arterial pH of 7.00 or less, and/or a base deficit of -14 mEq/L or more negative. Seizures developed in 5 (5.2%) of the 96 infants. High-risk markers included FHRT abnormalities only (n=36), FHRT abnormalities and MSAF (n=20), MSAF only (n=23), abruptio placentae (n=6), intubation in the DR (n=44), intubation in the neonatal intensive care unit (n=22), chest compressions (n=2), 5-minute Apgar scores of 5 or less (n=21), umbilical cord arterial pH of 7.00 or less (n=21), and base deficits of -14 mEq/L or more negative (n=19). By univariate analysis, significant relationships with seizures were found with Apgar scores, the need for intubation in the DR, umbilical cord arterial pH, and base deficit. Combinations of the identified risk markers showed a strong relationship with seizures with the following odds rations (ORs), 95% confidence limits, sensitivity, specificity, and positive predictive values (PPVs): (1) low cord pH and intubation, OR, 163 (confidence limits, 7.9 and 3343.7); sensitivity, 100%; specificity 94%; and PPV, 50%; (2) low cord pH and low 5-minute Apgar score, OR, 39 (confidence limits, 3.9 and 392.5); sensitivity, 80%; specificity, 91%; and PPV, 33.3%; and (3) low pH, intubation, and low 5-minute Apgar score, OR, 340 (confidence limits, 17.8 and 6480.6); sensitivity, 80%; specificity, 98.8%; and PPV, 80%. A combination of high-risk postnatal markers, specifically, a low 5-minute Apgar score and intubation in the DR in association with severe fetal acidemia, facilitates the identification within the first hour of life of term infants at highest risk for developing seizures secondary to perinatal asphyxia.

Risk factors for meconium aspiration syndrome

To identify potential predictors of meconium aspiration syndrome (MAS) in pregnancies complicated by moderate or thick meconium-stained amniotic fluid (AF). In the period 1990-1993, 937 vertex singleton pregnancies with moderate or thick meconium-stained AF were delivered; of these, 39 neonates developed MAS and 898 did not. The two groups were compared retrospectively according to maternal findings, pregnancy outcome, and neonatal complications, using univariate analysis (P < .05 considered significant) and stepwise multiple logistic regression analysis to identify independent significant factors for prediction of MAS and to calculate odds ratios (OR) and 95% confidence intervals. The two groups had a similar mean gestational age at delivery and birth weight. They also had similar incidences of post-dates pregnancies, small and large for gestational age infants, and amnioinfusion use. Univariate analysis identified significant differences between the two groups in 13 variables, two of which were excluded from logistic analysis because of inadequate data. Logistic regression analysis identified only six variables with independent, statistically significant effects on MAS: admission for induction with nonreassuring fetal heart tracing (OR 6.9), need for endotracheal intubation and suctioning below the vocal cords (OR 4.9), 1-minute Apgar score of 4 or less (OR 3.1), present cesarean delivery (OR 3.0), and previous cesarean delivery (OR 2.5). Cigarette smoking was associated with a lower risk for MAS (OR 0.07). The presence of at least one of the five risk factors had a sensitivity of 92%, a specificity of 56%, a positive predictive value of 8%, and a negative predictive value of 99% for MAS. Considering the high negative predictive value of the test, infants without any risk factors will not develop MAS and thus can be safely allowed to room with their mothers. Furthermore, this model helps to identify infants who may benefit from 24-hour observation and in counseling women about the neonatal risk for developing MAS.

The impact of a policy of amnioinfusion for meconium-stained amniotic fluid

To evaluate the impact of an amnioinfusion (AI) policy for thick or moderate meconium-stained amniotic fluid (AF) on neonatal outcome, specifically meconium-aspiration syndrome and its complications. We reviewed maternal and neonatal charts of 937 vertex, singleton pregnancies complicated by moderate or thick meconium-stained AF during a 3-year period. The patients were divided into groups according to whether AI was performed. Demographic characteristics, risk factors, mode of delivery, pregnancy outcome, and neonatal complications, including meconium-aspiration syndrome, were analyzed. Four hundred forty patients (47%) received AI (AI group); 497 (53%) did not, for the following reasons: imminent delivery (310 patients), occult meconium (141), or emergency cesarean delivery (46) (no-AI group). Our study did not show any reduction in the incidence of 5-minute Apgar scores of 7 or less (8 versus 7%), meconium below the vocal cords (28 versus 29%), meconium aspiration syndrome (4.5 versus 3.8%), ventilation requirement (4.3 versus 2.4%), or neonatal death (0.7 versus 0.2%) in the AI and no-AI groups, respectively. The AI group had a higher incidence of fetal heart rate abnormalities in labor (48 versus 31%, P < .05), instrumental delivery (15 versus 8%, P < .05), cesarean delivery (28 versus 17%, P < .001), and endometritis (21 versus 13%, P = .004). With the policy of routine AI for moderate or thick meconium-stained AF, AI was not clinically feasible in 53% of the cases. We were unable to demonstrate any improvement in neonatal outcome in those who received AI for moderate or thick meconium.

Meconium Stained Amniotic Fluid – A Potential Predictor Of Meconium Aspiration Syndrome

Objective: To identify potential predictors of Meconium Aspiration Syndrome (MAS) in pregnancies complicated by meconium-stained amniotic fluid (MSAF) &amp; to review the incidence, morbidity and mortality of Meconium Aspiration Syndrome (MAS). Methods: In the period of 2003 to 2006,175 pregnancies with thick meconium-stained AF were delivered; of these, 15 neonates developed MAS and 160 did not. The two groups were compared retrospectively according to maternal findings, pregnancy outcome, and neonatal complications, using univariate analysis (P &lt; 0.05 considered significant) and stepwise multiple logistic regression analysis to identify independent significant factors for prediction of MAS. Results: Incidence of MSAF was 13.97% and that of MAS was 8.57%. All deliveries associated with thick MSAF had developed MAS. 40% mothers were associated with PROM &amp; prolonged labour. Most common &amp; significant risk factors associated with MAS were increased gestational age, increased cesarean section (LSCS) &amp; low Apgar scores at 1 minute and 5 minute. Mortality rate was 6.66% &amp; mechanical ventilation was used in only 1(6.66%) case. Conclusion: MAS are associated with higher incidence of LSCS, lower 1 minute &amp; 5 minute Apgar score &amp; higher gestational weeks. 40% mothers were associated with PROM &amp; prolonged labour. The neonatal morbidity &amp; mortality is significantly more frequent in relation to thick meconium stained amniotic fluid. Specific delivery room resuscitation procedure, early diagnosis &amp; proper management can prevent development of MAS as well as morbidity &amp; mortality. Key words: Meconium Stained Amniotic Fluid, Meconium Aspiration Syndrome and Apgar Score. DOI = 10.3126/jnps.v28i1.1397 J. Nepal Paediatr. Soc. Vol.28(1) p.3-6