Pregnancy outcome after large loop excision of the cervical transformation zone

Our purpose was to determine whether large loop excision of the cervical transformation zone affects the outcome of pregnancy after 20 weeks' gestation.

In a retrospective case control study 40 women who had undergone large loop excision of the cervical transformation zone and were subsequently delivered at Dudley Road Hospital were identified between January 1989 and January 1992. Eighty controls were identified and matched for age, parity, and ethnic group from women delivered immediately before and after index cases. Variables included maternal performance in labor and smoking habits and perinatal outcome. Maternal factors analyzed included pregnancy gestation, length of the first and second stages of labor, use of oxytocin, analgesia, mode of delivery, estimated blood loss, whether labor was spontaneous or induced, and if preterm spontaneous rupture of membranes occurred. Perinatal outcome measures included whether the infant was liveborn, fetal weight, the presence of fetal abnormalities, and admission to the neonatal unit.

Women delivered after large loop excision of the cervical transformation zone had infants of significantly lower birth weight than did controls. They were also significantly more likely to have admitted to smoking on admission.

Previous studies investigating pregnancy outcome after local destructive methods of treating cervical intraepithelial neoplasia have been generally reassuring. However, in this study women who were delivered after large loop excision of the cervical transformation zone had significantly smaller infants. Although this may be related to the characteristics of women who have cervical intraepithelial neoplasia (for example, their smoking habits), larger adequately controlled studies should be performed before colposcopists can be justified in adopting a liberal attitude to treating all women with abnormal smears.