Procedure: Artificial Rupture of Membranes

Artificial rupture of membranes (aka amniotomy) may be done in order to perform certain interventions in labour (such as insertion of an intrauterine pressure catheter or placement of a fetal scalp electrode) or as a way of inducing/augmenting labour in conjunction with an oxytocin infusion. The fetus must be engaged with normal cephalic presentation, and it cannot be done if the clinician can palpate a cord on vaginal exam. It is also contraindicated if the mom has untreated HIV or active hepatitis B or C infections.

Equipment needed to complete the procedure:

• Sterile gloves, as well as a gown, mask, and eye protection
• Drapes for mom
• Amniotomy hook
• Absorbent towels/pads
• Electronic fetal monitor

Steps to performing an amniotomy are as follows:

1. Obtain consent: The procedure should be explained to the patient, as well as its possible benefits and risks and any alternatives. Specifically, the patient should be informed about the risk for cord prolapse and the precautions that the clinician will take to avoid this (making sure the head is well applied and the absence of a palpable cord). The possible increased risks for infection (and need for antibiotics) and bleeding should also be explained. Rupture of membranes commits the patient to delivery, usually within 24 hours. After 24 hours, the risk for chorioamnionitis is increased significantly, so cesarean delivery may be indicated or necessary. As well, rarely, the infant's head could be scratched or cut, but this is unlikely with an experienced clinician.
2. Fetal heart rate assessment: This must be done before, during, and after the procedure (for at least 30 minutes)
3. Gown up! Ensure you protect yourself with standard blood and body fluid precautionary measures.
4. Positioning: The patient should be in a recumbent position, with legs in the frog-legged position or else in stirrups. 
5. Perform a vaginal exam to ensure that the cervix is sufficiently dilated (to properly assess the following features but also to be able to actually perform the procedure), that the amniotic membrane is still intact, that the fetal head is well-applied, and that there is no palpable umbilical cord. 
6. With the index and middle fingers of your nondominant hand, palm up, insert the fingertips into the uterus and against the membranes. Be confident of what you are feeling before proceeding to avoid inadvertently damaging maternal tissue. 
7. With your dominant hand, insert the amniotomy hook between the two fingers of your other hand that are applied against the membranes. At this point, the hook should be pointed downward and away from the membranes.
8. Have an assistant apply gentle suprapubic pressure (which should increase the amount of fluid between the fetal membranes and fetal head, then rotate the hook 180 degrees to bring the sharp part into contact with the membranes and rupture them. When the membranes are ruptured, fluid will leak from the vagina.
   
9. Keeping the fingers of your nondominant hand in place, remove the hook and note the volume and colour of the fluid that has leaked out. Be sure to confirm the umbilical cord has not prolapsed, and then remove these fingers now adjacent to the infant's head. 
10. Monitor fetal heart rate to ensure it remains normal, and document the procedure.