Final answer:
A normal fetal heart rate pattern has a baseline heart rate of 110-160 bpm with minimal variability. Sinusoidal rhythm is an abnormal pattern with smooth, regular waves. Late deceleration occurs when the fetal heart rate decreases after the peak of a contraction.
Step-by-step explanation:
A normal fetal heart rate pattern, also known as a sinusoidal rhythm, typically shows a baseline heart rate between 110 and 160 beats per minute. It has a uniform appearance with minimal variability. Sinusoidal rhythm is an abnormal pattern characterized by smooth, regular, and symmetric waves that resemble a sine wave. Late deceleration is a pattern where the fetal heart rate decreases later than the peak of the contraction, indicating decreased blood flow to the fetus. Variable deceleration is characterized by abrupt, rapid drops in the fetal heart rate that vary in shape, depth, and duration and are not associated with contractions. Early deceleration is characterized by a gradual decrease and return to the baseline of the fetal heart rate in response to contractions.