The nurse-midwife orders fentanyl 12.5 mg IV now for the laboring mother.

Fentanyl from the pharmacy comes in 50 mg/ml vials.

How many ml would the nurse draw up for the injection?

Choice A rationale

The cardinal movement of extension occurs when the baby's head is delivered. After internal rotation, the fetus's head is in a posterior-facing position. The head must then "extend" as it passes under the pubic symphysis, allowing the nape of the neck to pivot and the face to emerge from the birth canal.

Choice B rationale

Expulsion is the final cardinal movement of labor. It occurs after the delivery of the baby's head. The anterior shoulder is delivered first, followed by the posterior shoulder, and then the rest of the baby's body is expelled from the birth canal.

Choice C rationale

Internal rotation is a cardinal movement that occurs earlier in the labor process. The fetal head, which is typically in a transverse position upon entering the pelvic inlet, rotates approximately 90 degrees to align with the anteroposterior diameter of the maternal pelvis, allowing it to descend further.

Choice D rationale

Flexion is a cardinal movement that occurs as the fetal head descends into the pelvis. The fetal chin tucks to the chest, presenting the smallest diameter of the head to the pelvic inlet. This movement is essential for a smooth descent through the birth canal.

Choice A rationale

A fetus in a longitudinal lie, cephalic presentation, is positioned with its long axis parallel to the mother's spine, with the head presenting first. This is the most common and favorable position for vaginal delivery. The illustration depicts a vertical alignment of the fetus within the uterus.

Choice B rationale

A transverse lie is a fetal malpresentation where the long axis of the fetus is perpendicular to the long axis of the mother. The fetus's head and buttocks are positioned to the sides of the mother's abdomen, with the shoulder or trunk presenting first.

Choice C rationale

A fetus in a longitudinal lie, breech presentation, is positioned with its long axis parallel to the mother's spine. The fetal buttocks or feet are presenting first into the pelvic inlet. The illustration depicts a vertical alignment of the fetus with the head at the top of the uterus.

Choice D rationale

An oblique lie is an unstable fetal position where the fetal long axis is at an angle to the maternal long axis. This position often converts to a longitudinal or transverse lie during labor. The illustration depicts an angled fetal position, but it is not a true transverse lie. .