Birth trauma. A five-year review of incidence and associated perinatal factors

To determine the current incidence of clavicular fracture (CF), facial nerve injury (FNI) and brachial plexus injury (BPI) and identify the existence, if any, of associated perinatal factors with each injury.

A case-controlled study design was selected and the study conducted for births between January 1, 1985 and January 1, 1990, at Christ Hospital and Medical Center, a tertiary care center with level III perinatal services in suburban Chicago. Among a population of 19,370 consecutive deliveries, we identified the occurrences of CP, FNI and BPI by database search, and maternal and neonatal chart reviews. A control group was randomly selected. Maternal, labor, delivery and neonatal variables were then compared between the birth trauma and control groups for each specific injury.

The incidence per 1,000 live births and per 1,000 live-born cephalic singletons delivered vaginally for CF was 4.5 and 5.7; for FNI, 0.6 and 0.7; and for BPI, 0.9 and 1.1, respectively. To varying degrees, the data demonstrate that the occurrences of these injuries are associated significantly more often with prolonged gestation, epidural anesthesia, prolonged second stage of labor, oxytocin use, forceps delivery, shoulder dystocia, macrosomia, low Apgar scores and a previous maternal obstetric history of macrosomia when compared to controls. Other significantly associated variables include the presence of meconium in labor and neonatal hyperbilirubinemia. Despite the presence of multiple perinatal factors that are individually associated statistically with the injured groups, multiple logistic regression analysis predicted 44.2% of CF's, none of the FNIs and only 19% of the BPIs.

While multiple perinatal variables are statistically associated with the specific birth injuries studied, the use of multiple logistic regression analysis shows that the ability to predict these injuries is markedly limited.