Perinatal consequences of disproportionate fetal trunk growth

Abstract

Objective: To identify the impact of an abnormally large neonatal chest circumference relative to head circumference on labor and neonatal morbidity. Methods: We used a retrospective cohort design to study 54 obstetric cases in which the neonatal thoracic circumference was ≥2.5 cm greater than that of the head. For each case we sought controls with a smaller thorax-head circumference difference. Ninety-seven controls were matched with their respective cases for birth weight, parity, maternal body mass index (BMI), and maternal ethnicity. Results: Cases had significantly smaller heads and larger trunks than controls (P < 0.0001). Cases were twice as likely (39% vs 19%, P = 0.007) to require admission to the neonatal intensive care unit. There was no significant difference between cases and controls in the frequency of shoulder dystocia, long second stage, or long deceleration phase of labor. However, compound presentations occurred more frequently in the cases than in controls (5.5% vs 0%, P = 0.044). Conclusion: Babies with disproportionately large trunk growth were at risk for requiring neonatal intensive care and for compound presentation.

Shoulder Dystocia: Prediction and Management

“…The fetus of a diabetic is prone to central growth and adiposity, with the trunk relatively large compared with the head [37,45]. In fact, this disproportionate growth affects large babies of nondiabetics, and helps explain the high incidence of shoulder dystocia among them [45,46].…”