Our objective was to investigate the association between maternal height and shoulder dystocia in women with and without diabetes.
This is a retrospective cohort study of singleton, non-anomalous, term pregnancies between 2007 and 2011 using linked vital statistics and ICD-9 data. Chi-square tests were used to compare rates of shoulder dystocia by maternal height and diabetes status. Height was stratified in 2 inch increments from 56 inches (4' 8") to 72 inches (6' 0"). Multivariable logistic regression was used to estimate adjusted odds ratio (aOR) and 95% confidence interval (CI) of shoulder dystocia by height and diabetes status. Regression analysis controlled for maternal BMI, race/ethnicity, age, education, insurance status, and prenatal care.
In a cohort of 2,069,817 pregnant women, we found that increasing maternal height was associated with decreasing prevalence of shoulder dystocia, independent of diabetes status. After controlling for confounders of interest, there remained a statistically significant decrease in the odds of shoulder dystocia as height increased (aOR 0.97, 95% CI 0.97-0.98). When compared to women without diabetes, those with diabetes had significantly increased odds of shoulder dystocia (aOR 1.61, 95% CI 1.54-1.68), independent of maternal height.
While height is not a modifiable risk factor for shoulder dystocia, odds of this adverse obstetrical outcome should be addressed in patient education and counseling. Particular consideration for shoulder dystocia risk should be given to pregnant women with diabetes and short stature.