The relationship between cesarean delivery and fecundability: a population-based cohort study

Area of Science:

• Reproductive Health
• Obstetrics
• Epidemiology

Background:

• Previous research indicates a correlation between cesarean delivery and reduced subsequent pregnancies.
• Cesarean delivery is more prevalent in women with lower fecundability, but the causal link remains unclear.

Purpose of the Study:

• To investigate the bidirectional relationship between cesarean delivery and fecundability.
• To determine if cesarean delivery impacts a woman's ability to conceive and if reduced fecundability increases the likelihood of cesarean delivery.

Main Methods:

• Prospective cohort study utilizing data from the Norwegian Mother, Father, and Child Cohort study and the Medical Birth Registry of Norway.
• Estimated fecundability ratio and infertility risk based on previous delivery mode in 42,379 women.
• Assessed cesarean delivery risk based on fecundability (time to conception) in 74,024 women.

Main Results:

• Women with a prior cesarean delivery had a 21% higher risk of infertility and a 10% lower fecundability ratio compared to those with vaginal delivery.
• Women requiring 12 or more cycles to conceive had a 57% higher risk of cesarean delivery compared to those conceiving within 2 cycles.
• These associations persisted across parity groups after adjusting for confounders.

Conclusions:

• A bidirectional relationship exists between cesarean delivery and fecundability.
• Women with previous cesarean delivery exhibit lower fecundability and higher infertility risk.
• Reduced fecundability is associated with an increased likelihood of cesarean delivery, suggesting potential shared underlying factors rather than direct causation by the procedure itself.