Translate the obstetric measures 5 cm, 50%, and +1 in a laboring woman.

• A. 5 cm dilated; 50% effaced; +1 station
• B. 5 cm dilated; 50% effaced; 1 cm below the ischial spine
• C. 5 cm dilated; 50% effaced; -1 station
• D. 5 cm dilated; 50% effaced; 2 cm above the ischial spine

Answer: (B)

In labor, dilation measures how open the cervix is, effacement describes how thin the cervix has become, and station tells how far the baby’s presenting part has descended relative to the ischial spines in the pelvis. So, 5 cm dilation means the cervix is moderately open, 50% effaced means the cervix is half-thinned, and the +1 station means the presenting part is 1 centimeter below the ischial spine (i.e., a little lower in the pelvis). That combination translates to 5 cm dilated; 50% effaced; +1 station, which is the same as saying the presenting part is 1 cm below the spine. The other phrasings would place the presenting part in different positions (above the spine or at a different distance), so they don’t match the given +1 measurement.