New research has asked whether a public health campaign may be needed to inform women that deferring childbirth until after the age of 30 may increase the chances of birth interventions such as Caesarian section delivery.
The study, published in the Irish Journal of Medical Science, explored whether an increase in the number of CS deliveries was linked with being overweight or obese.
But it found that while the odds of an obese woman having a CS have increased for those who already have at least one child, age was the most likely factor for any increase in CS rates among those having a baby for the first time.
According to the research paper, entitled 'Does maternal obesity explain trends in caesarean section rates?
Evidence from a large Irish maternity hospital' and authored by experts in the ESRI, almost one-in-five women who delivered in 2017 in the Coombe Women and Infants University Hospital was obese at her first antenatal visit and the number of women with obesity "has been shown to be increasing over time".
It said that between 2010 and 2017, the proportion of obese women delivering in the Coombe increased by 18.1%.
Researchers sought to examine whether trends in maternal BMI were a contributing factor to the increase in the prevalence of CS and began by looking at the records of all 50,992 women who gave birth in the Coombe Hospital between January 2009 and the end of December 2014.
According to the research: "This observational study in a large maternity hospital found that while the prevalence of being overweight or obese changed little over the years 2009 to 2014, the odds of having a CS if a woman was obese increased in multiparas.
However, a strong driver of increased CS rates, regardless of parity, was advancing maternal age which is important because national data has shown that Irish women are increasingly choosing to defer childbirth until later in life.
"Is a public health campaign required to inform women that deferring childbirth until after 30 years of age may increase their risk of interventions such as CS?" it said.
"Is the increase in CS rates in older women due to deteriorating reproductive performance or it is due to a lower threshold for obstetric intervention? Women need to be made aware that deferring childbirth until after 30 years of age increases their risk of CS, whether they are obese or not."