The study was carefully designed to control for “validated maternal, fetal, and placental conditions and maternal demographics,” and used data only from New Jersey (which the author states had “the second-highest cesarean delivery rate among 19 state releasing all-payer data and the fourth-highest rate of cesarean delivery without apparent medical indication, according to HealthGrades”). Looking at hospital discharge data from 2004-2007, the author looked at data for 362,611 women admitted for delivery who had no previous cesarean delivery and who were identified as privately insured (through commercial HMO plans, BlueCross, or other commercial plans); insured by Medicaid; or self-paying. The author also collected administrative codes to determine whether a cesarean took place, whether there were any complications of labor, maternal demographics, and other conditions that may indicate the need for a cesarean delivery.
Interesting points from the study:
- “In the first quarter of 2004, the rate of prelabor cesarean delivery was 12.0% of all women without previous cesarean delivery; this rate rose to a high of 15.2% in the final quarter of 2007.”
- Most of the prelabor cesarean deliveries occurred in women with at least one of 26 identified conditions constituting a “high-risk pregnancy” but rates did rise over the same period of time for women with none of the indications for prelabor delivery (rising from 0.6% to 0.9% over the course of the study period).
- “Self-paying women and Medicaid recipients had the lowest rates of prelabor primary cesarean delivery (10.8% and 11.5%, respectively); women who were privately insured with BlueCross plans had the highest rate (16.0%).”
- Privately insured women tended to be older (5-6 years) than self-paying or Medicaid-insured women, and self-paying and Medicaid-insured women were “overwhelmingly” minority races.
- The most common medical indication for a primary cesarean delivery without a trial of labor was “fetal heart rate abnormality,” which the authors describes as a “poorly defined cardiotocography diagnosis…previously identified as associated with primarily cesarean delivery…may be applied to both fetal brachycardia and tachycardia and to increased or decreased heart rate variability, and it may be associated with uterine contractions.”
- Most of the indications for prelabor cesarean delivery were skewed towards the privately insured patients, although a history of genital herpes and a background of mental illness were both more likely in the self-paying and Medicaid-insured categories.
- The author felt that while the study was likely to minimize or omit factors such as obesity, “[s]cant evidence has been found for a causal relationship between obesity and prelabor cesarean delivery in women without previous cesarean delivery. Obesity increases maternity care costs, but the overall cesarean delivery rate has not conclusively been shown to be associated with weight gain or obesity.”
- “Almost all primary prelabor cesarean deliveries are performed in women with at least 1 high-risk condition (94% in my data).”
- There was evidence of “small but consistent increases in the likelihood that women with more comprehensive insurance will have a prelabor cesarean delivery” but the author was unable to detail a specific cause.
The author was very clear that more studies needed to be done in the area. “My analysis focused on relative differences in procedure rates between series of women and I was thus unable to confirm whether one rate is too high or another too low.” In addition, the author feels that further research may be better able to determine whether physician-induced demand for financial interest; pure maternal preference based on fear of pain or pelvic floor disorders; physican, maternal, or site preferences for scheduling; insurance benefits to cesarean delivery; or any of a myriad of other possible factors are driving the difference in prelabor cesarean delivery rates between variously insured women.
Note that the study focuses on prelabor cesarean deliveries and does not include deliveries that take place after labor began in order to focus as much as possible on the ‘elective’ issue. The indications for high-risk delivery discussed by the author included everything from abnormal fetal heart rate to malpresentation, from macrosomia to multiple gestation pregnancies and fetal congenital anomalies.