Caesarean section rates in primigravid women categorised by age and BMI

The rising caesarean section (CS) rate is a complex issue, particularly in an increasingly heterogenous nulliparous population. The study aim was to stratify the CS rate in nulliparous women by age and BMI to determine if any difference existed. This was a retrospective review of CS procedures of nulliparous women in two centres in Ireland (2014 through 2017). Data were obtained for 17,177 women from the hospital databases and CS procedures determined for each age and BMI category. Significant differences were observed when CS rates were stratified in this manner. The CS rates for women <20 years/BMI < 18.5 was 8.8 versus 57.6% for women 35 - 39 years/BMI 30 - 34 and 76 - 100% for all women >45 years (p<.005). The development of customised charts subdivided by age and BMI may be a useful counselling tool and assist in the comparison of rates between units.Impact statementWhat is already known on this subject? It is well known that along with rising CS rates globally, there have also been significant changes in maternal demographics-with increasing maternal age at first birth and increasing maternal BMI. It is well established that both of these factors affect the rate of CS in a population.What do the results of this study add? This study sought to stratify the CS rate in nulliparous women by age and BMI to determine if any difference existed. The results of the study showed an increasing CS rate for increasing age and BMI categories that was statistically significant.What are the implications of these findings for clinical practice and/or further research? Additional research using larger population data sets could allow the development of customised charts for nulliparous women subdivided by age and BMI which could act as a useful counselling tool in clinical practice, as well as assist in the comparison of CS rates between units.