Objective. Evaluate the effect of cervical conization on preterm birth/low birth weight (LBW).
Design. A systematic review of the literature using external or internal controls.
Results. The typical odds ratio for preterm delivery in women with prior cervical conization using external controls was 3.23 (95% confidence interval 2.29–4.55). Using internal controls the typical odds ratio for LBW was 2.97 (95% confidence interval 1.09 8.05). Using external controls the typical odds ratio for LBW was 2.31 (95% confidence interval 1.33-3.99).
Conclusion. Women with cervical conization are at higher risk for preterm birth than external controls, and the surgical intervention as such is a major determining factor.