Rates and indications of cesarean delivery in the preterm population
delivery is associated with increased maternal morbidity, but rates are increasing in
the United States. Many national strategies have been implemented in an attempt to
decrease the cesarean delivery rate; however, these strategies are typically aimed
toward full term pregnancies. Cesarean delivery rates and the operative indications for
cesarean have not been previously ... read morereported for preterm patients. We therefore aimed to
examine the relationship between preterm delivery and cesarean delivery by reviewing
hospital rates in the state of Massachusetts in a hospital-based analysis, and by
examining patient characteristics from a sample of patients from one tertiary care
center in Massachusetts. This was a retrospective analysis of all 45 Massachusetts
delivery hospitals in 2014, and of all deliveries that occurred at a tertiary care
center from 2009-2015 to evaluate the relationship of preterm delivery with cesarean
delivery. A large range in rates for preterm delivery (1.9% to 27.8%), all cesarean
delivery (19.7% to 46.7%), and primary cesarean delivery (11.1% to 33.6%) was noted for
Massachusetts hospitals. From our hospital-based study, after multivariable adjustment
for hospital characteristics with a linear regression model, we found a 5% increase in
hospital preterm delivery rate was associated with a 2.8% increase in hospital cesarean
rate (p=0.01), and a 2.6% increase in primary cesarean rates (p<0.01). In our
patient-based tertiary care center study, there were 6994 total deliveries, with 1864
(26.7%) preterm births, 2929 (41.9%) total cesareans, and 1822 (26.1%) primary
cesareans. Results of a multivariable logistic regression indicated that preterm birth
status was associated with approximately two times higher odds of cesarean delivery
(ORadj=1.92, 95% CI 1.71-2.17, p<0.001) and primary cesarean delivery (ORadj=2.03,
95% CI 1.77-2.32, p<0.001). An increase of 5 weeks in gestational age was associated
with 33% lower odds of both total and primary cesarean delivery (ORadj= 0.67, 95% CI
0.62-0.73, p<0.001). Repeat cesarean delivery was the most common indication for
cesarean overall in both term and preterm patients. Overall, clinically indicated
cesarean deliveries made up the majority of all cesarean and primary cesarean preterm
deliveries (75.2% and 88.1%, respectively), and truly elective cesareans accounted for
0.01% of preterm deliveries. Preterm delivery is significantly associated with increased
risk of cesarean delivery using both hospital and individual patient level data, even
after adjusting for other cesarean risk factors. Notably, the majority of preterm
cesareans were performed for clinically indicated reasons, and the most common
indications for preterm cesarean are not amenable to a trial of labor. Thus, preterm
delivery is a significant risk factor for cesarean delivery, and the majority of preterm
cesareans may be unavoidable.
Thesis (M.S.)--Tufts University, 2017.
Submitted to the Dept. of Clinical & Translational Science.
Advisor: Jessica Paulus.
Committee: Robin Ruthazer, and Sabrina Craigo.
Keyword: Obstetrics.read less