Effacement, Dilation, and Station

Definition: Effacement refers to the thinning and shortening of the cervix as the body prepares for labor and childbirth.
Process: Before labor begins, the cervix is typically long and firm, acting as a protective barrier between the uterus and the outside world. As labor approaches, the cervix begins to soften, thin out, and shorten, allowing it to open more easily when contractions start.
Measurement: Effacement is measured in percentages. A cervix that is 0% effaced is thick and long, whereas a cervix that is 100% effaced is completely thinned out, ready for delivery.
- Example:
  - 0% effaced: The cervix is unchanged and thick.
  - 50% effaced: The cervix is halfway thinned out.
  - 100% effaced: The cervix is fully thinned and ready for dilation to progress.

Definition: Dilation refers to the opening of the cervix during labor. The cervix must open wide enough to allow the baby to pass through the birth canal.
Process: As labor progresses, uterine contractions cause the cervix to gradually open or dilate. This process is essential for the baby to be born vaginally.
Measurement: Dilation is measured in centimeters (cm), ranging from 0 cm (completely closed) to 10 cm (fully dilated).
- Example:
  - 0 cm dilated: The cervix is closed. (1-2cm will most likely be sent home)
  - 4 cm dilated: Early active labor; contractions are stronger and more regular.
  - 10 cm dilated (COMPLETE): The cervix is fully open and the baby can begin moving through the birth canal.
  Recommended to stay home and labor as long as possible

Definition: Station refers to the position of the baby’s head (or presenting part) in relation to the mother’s pelvis. It indicates how far the baby has descended into the birth canal.
Process: The baby’s head moves down through the mother’s pelvis as labor progresses. The position of the baby's head is compared to certain landmarks in the pelvis to determine the station.
Measurement: Station is measured in numbers ranging from -5 to +5.
- Negative numbers: Indicate the baby’s head is higher up in the pelvis (not yet engaged).
- Zero station (0): The baby’s head is "engaged" and aligned with the ischial spines (bony points in the pelvis), considered the midpoint.
- Positive numbers: Indicate the baby’s head is moving lower into the birth canal, preparing for delivery.
- Example:
  - 5 station: The baby’s head is still high and not engaged.
  - 0 station: The baby’s head is at the level of the ischial spines, meaning it's engaged in the pelvis.
  - +3 to +5 station: The baby’s head is descending further and close to crowning (emerging from the birth canal).