- In the first stage of labor, the circular muscle at the base of the uterus, the cervix, must thin (efface) and open (dilate) to a diameter of about 10 cm (4 in) to allow the fetal head to pass through.
- The cervix is opened by repeated uterine contractions pushing the presenting part of the fetus against the inside of the uterus, each time thinning and opening it more.
- The fetal presenting part is considered to be engaged (0 station) when the lowest portion is at the level of the ischial spines. Movement down the birth canal is measured by positive stations, some using a 0/+3 scale, and some using a 0/+5 scale.
- The second stage starts at full dilatation of the cervix and is completed when the fetus is delivered. The third stage is delivery of the placenta.
30 x 40 = $395 + shipping
36 x 48 = $425 + shipping
Digital = $395