In recent years there has been growing concern about the rise in births by cesarean section. In 2013, on average, in the countries of the OECD, approximately 1 out of every 4 births involved a cesarean section, while the figure for the year 2000 was 1 in 5 (OECD, 2013). This increase has been associated with greater complications and higher maternal and child mortality and morbidity, compared with vaginal births.

However, several of the studies that come to these conclusions compare mothers who give birth vaginally and by cesarean section, and this may produce biased results: mothers who give birth by caesarean section may have different characteristics from those who have vaginal births, and this may influence the health outcomes of the child and the mother after delivery.

Following the WHO recommendations to conduct research to better understand the immediate and future effects of cesareans on health in the long term, a study by the Economy and Health Research Centre (CRES-UPF) wishes to help fill this information gap. The authors of the research are Ana Maria Costa-Ramón and Ana Rodríguez-González, PhD students at UPF’s Department of Economics and Business, and Miquel Serra-Burriel and Carlos Campillo-Artero, also linked to the University of Barcelona and the Balearic Islands Health Service, respectively.

The study, published in the Journal of Health Economics in May 2018, provides further evidence of a causal link between unplanned cesareans and the health of the newborn, but it does so by focusing on an exogenous variable, which is not related to the maternal and fetal characteristics: the variation of number of unplanned cesareans depending on time of day at which they occur.

For obvious reasons, previously it had not been possible to conduct an experiment where mothers were randomly assigned to have a vaginal delivery or a caesarean section. In this study the variation in the rate of cesareans per hour allows comparing similar mothers who, depending on the time of birth, are more or less likely to have a cesarean section, mimicking the conditions that would be established in an experiment.

The results, obtained from a sample taken from public hospitals in Spain (6,163 birth records from four centres of different autonomous communities between 2014 and 2016) show that the rate of cesareans is highest during the first few hours of the night, between 11pm and 4am. Specifically, the rate of cesareans increases by 6.3 points, as compared to the rest of the day, taking into account that mothers who give birth during the day have similar characteristics.

Influence of the demand for free time and work shifts

According to the authors of the study, “other previous studies had already documented that variables related to the demand for free time by doctors could affect the rate of cesareans. This makes these time variables significant predictors of unplanned cesareans”, they claim.

The research highlights non-financial incentives as an important factor in the decision-making of medical care providers: “Our results suggest that physicians may be less tolerant of the natural progression of the work entailed in a delivery, which consumes a lot of time. The incentives related to leisure time are very important, and physicians are more predisposed to perform procedures that speed up the delivery. Therefore, there would be a need to review the incentives created by the shift structure and the long working hours of physicians in public hospitals, in order to reduce avoidable interventions”.

Impact of unplanned cesareans on the health of the newborn in the long term

“Our research suggests that non-medically indicated cesareans may have a significant, negative impact on the health of the newborn, as measured by the scores of the Apgar test, but the effect is not serious enough to translate into more extreme results”, claim the authors.

According to the study, cesareans lead to a decrease of about one point in the scores of the Apgar test carried out at 1 to 5 minutes after birth in healthy babies (the average Apgar scores at minute 1 and minute 5 are 8.9 and 9.8, respectively). Thus, the threshold analysis of Apgar scores confirms that the effects of cesareans are limited to the highest levels of this scale. Specifically, there is a greater likelihood of having an Apgar score at minute 5 below 10, 9 and 8.

Several previous studies have found that in the long term, people with Apgar scores of between 7 and 8 are more likely to drop out of school or repeat a year, and that those who obtain a score of between 7 and 9 are more likely to receive social assistance after the age of 18. Other studies indicate an increased risk of autoimmune and metabolic disorders in the long term. In any case, there is no evidence that these effects translate into a significant increase in the need for resuscitation or intensive care, or an increased risk of neonatal death.

Eliminating avoidable cesareans would lead to significant savings for the public health system.

According to the study data, since the rate of cesareans in the sample of public hospitals analysed is 16.5%, eliminating these avoidable cesareans would reduce the rate of cesareans by a 38.1%, or 245 cesareans a year. When you consider that the average cost of a caesarean section to the Spanish public health system is 1,692.97 euros more expensive than a vaginal birth, by eliminating these excessive cesareans, the sample hospitals could achieve a cost reduction of some 675,000 euros.

Applying this logic to all births that took place in public hospitals in Spain in 2014 would mean savings of more than 47 million euros for the state health system, a figure that, given the average salary of a specialist physician (45,970 euros) and the total number of public hospitals in Spain (453), would allow each hospital to hire more than two additional doctors. This would at the same time  help alleviate the need for long working hours.

Reference work: Ana Maria Costa-Ramón, Ana Rodríguez-González, Miquel Serra-Burriel and Carlos Campillo-Artero (May 2018). “It’s about time: Cesarean sections and neonatal Health”, Journal of Health Economics. https://doi.org/10.1016/j.jhealeco.2018.03.004