Labour and Delivery Skills Lab Notes

Vocabulary-style flashcards covering the stages of labour, mechanical factors, mechanisms of labour, and placental delivery as described in the NCM 107 Skills Lab notes.

Labour

The physiologic and mechanical process in which the baby, placenta, and fetal membranes are passed through the pelvis and expelled from the birth canal.

Powers

Mechanical factors consisting of processes like uterine contractions, intra-abdominal pressure, and external pressure by which the expulsion of the products of conception is accomplished.

Passages

Mechanical factors including the pelvis, soft parts (cervix and vagina), and the pelvic floor.

Passengers

The components being expelled during labour, specifically the fetus, placenta, and membranes.

Stage 1: Cervical Dilation

Begins with the onset of true labour and ends when the cervix is completely dilated at $10\,cm$.

Latent Phase

The first phase of Stage 1 ($0-4\,cm$) characterized by mild uterine contractions every $15$ to $30$ minutes, lasting $15$ to $30$ seconds.

Active Phase

The second phase of Stage 1 ($4-8\,cm$) characterized by moderate uterine contractions every $3$ to $5$ minutes, lasting $30$ to $60$ seconds.

Transition Phase

The third phase of Stage 1 ($8-10\,cm$) characterized by strong uterine contractions every $2$ to $3$ minutes, lasting $45$ to $90$ seconds.

Normal Fetal Heart Rate (FHR)

Assessed immediately after the rupture of membrane; the normal range is $120$ to $160$ beats per minute.

Stage 2: Expulsion Stage

The pushing phase that begins with complete dilation of the cervix and ends with the delivery of the infant, typically lasting $1$ to $2$ hours.

Lithotomy

The maternal position used during the preparation for Stage 2 (Expulsion).

Crowning

The stage of delivery where the fetal head is seen at the perineal opening.

Ritgen’s Maneuver

An obstetric procedure used to control the delivery of the fetal head by applying upward pressure to allow gradual extension and prevent anal sphincter injury.

Nuchal Cord

The presence of loops of the umbilical cord around the baby's neck.

Engagement

A mechanism of labour occurring when the biparietal diameter of the fetal head is engaged in the pelvis.

Descent

The downward passage of the presenting part through the pelvis, brought about by uterine contractions and maternal bearing down.

Flexion

The movement where the fetal chin is brought to the thorax due to resistance from the pelvic floor.

Internal Rotation

The movement where the fetal head rotates anteriorly toward the symphysis pubis or the hollow of the sacrum, usually at the level of the ischial spines.

Extension

Follows internal rotation as the head is born and becomes visible at the perineum (crowning).

Restitution / External Rotation

The stage where the head returns to the oblique position as the shoulders undergo internal rotation following the delivery of the head.

Stage 3: Placental Separation and Expulsion

The shortest stage of labour, lasting $5$ to $30$ minutes, involving the delivery of the placenta.

Schultz mechanism

The mechanism where placental separation is central in origin, causing the 'shining' part to be delivered first; involves little initial blood gush.

Duncan mechanism

The mechanism where placental separation starts at the edge, the maternal edge is seen first, and bleeding is evident in the early phase.

Brandt-Andrews Maneuver

A specific technique or method used for delivering the placenta from the uterus during the third stage of labour.

Normal Blood Loss

The estimated blood loss during the inspection of the placenta, typically around $500\,mL$.

Stage 4: Postpartum

The recovery period beginning after the placenta is expelled and lasting up to $4$ hours after birth.