This condition exists when the capacity of the pelvis is inadequate to allow the fetus to negotiate the birth canal. This may be due to a small pelvis, a nongynecoid pelvic formation, a large fetus, or a combination of these factors.
Brow presentation describes a fetal position when the baby’s head is extended back, with the forehead leading the way through the birth canal. The fetal head is midway between full flexion (vertex position) and hyperextension (face position) along a longitudinal axis. Because the diameter of the fetal head at this angle may be greater than […]
Breech presentation is defined as a fetus in a longitudinal lie with the buttocks or feet closest to the cervix.
A cephalic presentation is a situation at childbirth where the fetus is in a longitudinal lie and the head enters the pelvis first; the most common form of cephalic presentation is the vertex presentation where the occiput is the leading part (the part that first enters the birth canal). All other presentations are abnormal (malpresentations) […]
If a portion of the umbilical cord comes out of the cervix or vulva ahead of the fetus, this is called a prolapsed umbilical cord. Prolapsed umbilical cords are often preceded by variable decelerations of the fetal heart rate, demonstrated on the electronic fetal monitor.
Variable decelerations are variable in onset, duration and depth. They may occur with contractions or between contractions. Typically, they have an abrupt onset and rapid recovery.
A “deceleration” describes a decrease in the heart rate of the fetus from its baseline heartrate. “Late decelerations” are described as a transient decrease in the fetal heart rate occurring at or after the peak of a uterine contraction. Late decelerations may represent some degree of utero-placental insufficiency. All blood flow in and out of […]
Early decelerations are periodic slowing of the fetal heartbeat, synchronized exactly with the contractions. These dips are rarely more than 20 or 30 BPM below the baseline.
The normal fetal heart rate baseline is from 120 to 160 BPM and has both short and long-term “variability.” Short-Term variability means that from one moment to the next, the fetal heart speeds up slightly and then slows down slightly, usually with a range of 3-5 BPM from the baseline. Long-Term Variability represents broad-based swings […]
Fetal Tachycardia occurs when there is evidence of a sustained elevation of the fetal heart rate (baseline above 160 BPM) as seen on the Fetal Heart Tracings. A normal baseline fetal heart rate is between 120-160 BPM. Fetal tachycardia commonly occurs in the form of sinus tachycardia, which causes an increased heart rate when the […]