Objective: Shoulder dystocia (SD) is a risk factor for neonatal clavicular fracture (CF). Previous SD is a known risk factor for subsequent SD. It is unknown whether an isolated neonatal CF (one that is not associated with SD) increases the risk of future SD. We aimed to investigate this question.
Methods: A retrospective computerized database study conducted at Shaare Zedek Medical Center, a university-affiliated hospital, between 2005 and 2018. We included in the study all women that had a vaginal delivery without SD and had a subsequent vaginal delivery in our center between 2005 and 2018. Medical records of parturients who had a coded diagnosis of neonatal CF were retrieved. The first delivery with the neonatal diagnosis of an isolated CF was chosen as index delivery. Rates of SD at the subsequent delivery were assessed and compared between parturients with isolated neonatal CF (INCF) and parturients without neonatal CF or SD at the index delivery. To account for dependency between deliveries of the same individual parturient, we used generalized estimating equation (GEE) models.
Results: We identified 39,601 parturients that met the inclusion criteria. During the study period, 519 parturients with a diagnosis of INCF that had at least one subsequent delivery were identified (1.3%). Overall, 3.9% of parturients with isolated CF (20/519) had subsequent SD, as compared to 0.5% of parturients without CF or SD at the index delivery (190/39082; p < .01). Previous diagnosis of INCF was found to be independently associated with SD in a subsequent delivery after controlling for known risk factors for SD (aOR = 6.41, 95% CI = 3.92-10.61). Previous diagnosis of an INCF was also found to be independently associated with a subsequent event of SD in all subsequent deliveries of the same individual parturient (aOR = 3.42, 95% CI = 2.26-5.18).
Conclusion: Women with previous INCF have an increased risk for SD in subsequent deliveries. Intervention efforts directed at this particular subgroup of women should be applied, with special attention to potentially modifiable risk factors to minimize the risk for future SD.
Keywords: Clavicular fracture; individual risk; previous shoulder dystocia; shoulder dystocia; vaginal delivery.