Amniotomi

Amniotomi, or amniotomy, is the deliberate rupture of the amniotic membranes performed by a clinician during labor. It is often used to induce labor or to augment spontaneous labor when contractions are inadequate. The procedure may also enable internal fetal monitoring or the use of an internal uterine pressure catheter.

Indications include induction of labor when the cervix is favorable, augmentation of labor to accelerate progress, and the need for internal monitoring or instrumentation that requires ruptured membranes. It is typically considered after careful assessment of fetal status, presenting part position, and maternal conditions.

Technique and timing involve sterile preparation and monitoring of the fetus. An amniotomy hook or a fingertip may be used to rupture the membranes near the presenting part, producing a gush of amniotic fluid. After rupture, cervical dilation and labor contractions often progress, and oxytocin infusion may be adjusted accordingly. Fetal monitoring continues, and internal monitoring may be employed if membranes are ruptured.

Contraindications include placenta previa or vasa previa, active genital herpes infection, or conditions where rupture of membranes could compromise the fetus or mother. Abnormal presenting parts with risk of cord prolapse, active intrauterine infection, or certain placental abnormalities may also preclude the procedure.

Risks and complications are primarily infection with prolonged rupture of membranes, typically increasing after 18–24 hours, and umbilical cord prolapse, especially with a high presenting part. Other potential issues include placental abruption, cervical or vaginal trauma, and transient fetal heart rate changes.

Outcomes: when appropriate, amniotomy can shorten labor and facilitate delivery or monitoring, but it requires careful patient selection and ongoing maternal-fetal assessment.