[CRIB II score and method of delivery for very low and extremely low birth weight infants]

The purpose of this study is to determine the influence of method of delivery on CRIB II score in preterm infants born in vertex presentation < or = 32 weeks of gestation.

Prospective study over five years period (2006-2010) that includes 162 cases. 115 (71%) of patients are delivered vaginally and 47 (29%) with cesarean section. CRIB II score is used as a tool for measuring the risk of neonatal dead and severe morbidity in neonatal period. It's predictive value is based on the birth weight, gestation weeks, gender, the lowest values of BE (base excess) in the first hour of life and the temperature at acceptance in neonatal intensive care unit. There is a reciprocal dependence between CRIB II, duration of pregnancy and birth weight. This requires a comparison of vaginal birth and Cesarean section in the following subgroups: 25-26 weeks, 27-28 weeks, 29-30 weeks and 31-32 weeks and weight 500-750 g., 751-900 g., 901-1000 g., 1001-1250 g. and 1251-1500 g.

Mean score values for vaginal births are 14.08 p. (points) at 25-26 weeks, 10.54 p. at 27-28 weeks, 6.90 p. at 29-30 weeks and 5 p. at 31-32 weeks. In the same periods of pregnancy mean CRIB II in Cesarean section deliveries are 13, 6 p., 10, 58 p., 7, 85 p. and 5 p. Significant statistical difference is not found between groups. Results remained almost unchanged after adjusting for birth weight in vaginal and cesarean births.

The risk of poor perinatal outcome assessed by CRIB II is independent of the method of delivery but strongly influenced by the duration of pregnancy and birth weight.