Cesarean section on a rise-Does advanced maternal age explain the increase? A population register-based study.

Area of Science:

• Obstetrics and Gynecology
• Public Health
• Epidemiology

Background:

• Cesarean section rates in Denmark rose by 49% from 1998-2015, reaching 21% of all births.
• Cesarean births pose short- and long-term risks to mother and child, impacting future pregnancies.
• Increasing maternal age at childbirth is a potential contributor to the cesarean section rise.

Purpose of the Study:

• To investigate the association between advanced maternal age and cesarean section in Denmark.
• To assess the influence of demographic, anthropometric, health, and obstetric factors on this association.

Main Methods:

• A national population-based cohort study of 1,122,964 Danish births (1998-2015).
• Maternal age groups: <30 (reference), 30-34, 35-39, and 40+ years.
• Multivariate regression models adjusted for confounders, stratified by parity.

Main Results:

• A positive association was found between advanced maternal age and cesarean section risk.
• Nulliparous women aged 35-39 had double the risk (AOR 2.18); women 40+ had triple the risk (AOR 3.64).
• Multiparous women aged 35-39 had a 1.56 AOR, and those 40+ had a 2.02 AOR.

Conclusions:

• Cesarean section rates increase with maternal age, with minimal influence from adjusted risk factors.
• The association is stronger in nulliparous women.
• Obstetric culture and age-related labor progression may warrant further investigation as contributing factors.