amniotomy

Amniotomy, also known as artificial rupture of membranes (AROM), is the deliberate rupture of the amniotic sac by a clinician during labor. It is performed to hasten labor, to induce labor when combined with other treatments, or to enable internal fetal monitoring or use of certain intrauterine devices.

Indications include labor induction or augmentation, facilitation of internal fetal monitoring, and situations in which breaking the membranes may help contractions become more effective. The decision is guided by fetal status, cervical dilation, and the overall progress of labor.

Procedure and monitoring involve a sterile vaginal examination to confirm that the presenting part is engaged and the cervix is sufficiently dilated. An amniotic hook or digital rupture is used to create a small opening in the membranes, releasing amniotic fluid. After rupture, caregivers assess the fluid and continue fetal and uterine monitoring. If internal monitoring is planned, devices such as an intrauterine pressure catheter or a fetal scalp electrode may be placed through the ruptured membranes.

Risks include infection such as chorioamnionitis, umbilical cord prolapse (especially if the presenting part is not well engaged), placental abruption, heavy bleeding, and fetal distress. Prolonged rupture of membranes increases infection risk and may be associated with adverse outcomes.

Contraindications include placenta previa, vasa previa, active genital herpes, or other conditions that raise the risk of bleeding or infection. The procedure is generally avoided if there is high risk of cord prolapse or infection, or if the presenting part is not adequately engaged.

Alternatives include continuing labor with intact membranes and using other methods to induce or augment labor as indicated.