(1070) Rising cesarean delivery rates in contemporary obstetric practice - Suboptimal obstetric practice or perfectly justifiable?

The WHO has suggested that the “ideal” cesarean delivery (CD) rate should be < 15%, and that CD rates  >10% are not associated with mortality reduction. Obstetricians have been criticized for rising CD rates possibly being associated with higher uterine rupture (UtRu) during VBAC attempts, and higher peripartum hysterectomy (PH) due to placenta accreta spectrum. Our objective was to quantify the association between increasing CD rate, hypoxic ischemic encephalopathy (HIE), perinatal mortality rate (PMR), UtRu, and PH at a single tertiary obstetric unit over a 20-year time period.

Study Design:

A prospectively maintained database of all cases of HIE, perinatal mortality, uterine rupture and peripartum hysterectomy was interrogated for the 2003-2022 time period. HIE (grades 2 or 3) and corrected perinatal mortality rates (cPMR) were expressed per 1,000 births, and excluded cases with congenital malformation. UtRu and PH rates were expressed per 1,000 mothers delivered.

Results:

Over 20 years, 163,604 mothers delivered 167,005 babies, for an average of 8,180 mothers per year. The table demonstrates a significant increase in CD from 28.2% in 2003 to 39.0% in 2022 (38% increase), and was accompanied by a highly significant reduction in cPMR from 5.2 to 3.5 per 1,000, (33% decrease), with Spearman rank correlation of -0.83 (p< 0.001). Rates of UtRu and PH did not change significantly, at 0.00 and 0.30 per 1,000 in 2003, to 0.25 and 1.47 per 1,000 in 2022 respectively, with Spearman rank correlation of 0.33 (p=0.154). The rate of HIE did not change significantly, with a persistently low rate ranging from 1.47 to 1.21 per 1,000 from 2003 to 2022 respectively.

Conclusion:

Contrary to some prior claims, the 38% increase in CD rate noted at a single maternity hospital was associated with a highly significant improvement in perinatal outcome (33% reduction in PMR, and persistently low HIE rate) but without any negative impact on uterine rupture or peripartum hysterectomy. A higher CD rate than an assumed WHO "ideal" of < 15% is in fact associated with persistently low rates of perinatal mortality and HIE.