Examples of sexual risk behaviors associated with exposure to a sexually transmitted infection (STI) include: (Select all that apply.)

Choice A reason: Fetal sleep cycles are a normal physiological cause of decreased variability in the FHR, which is the fluctuation of the baseline FHR above and below 2 cycles per minute. Fetal sleep cycles usually last 20 to 40 minutes and do not affect the fetal well-being.

Choice B reason: Umbilical cord compression is an abnormal cause of decreased variability in the FHR, as it reduces the blood flow and oxygen delivery to the fetus. It can also cause variable decelerations, which are abrupt decreases in the FHR below the baseline.

Choice C reason: Altered cerebral blood flow is an abnormal cause of decreased variability in the FHR, as it indicates a compromise in the fetal central nervous system. It can also cause late decelerations, which are gradual decreases in the FHR after the peak of a contraction.

Choice D reason: Fetal hypoxemia is an abnormal cause of decreased variability in the FHR, as it reflects a severe lack of oxygen in the fetal blood. It can also cause sinusoidal pattern, which is a smooth, undulating waveform in the FHR.

Choice A reason: An FHR greater than 110 beats/min is not a sufficient indicator of fetal well-being during labor. The normal range of FHR is between 110 and 160 beats/min, but it can vary depending on the gestational age, fetal activity, and maternal factors. A high or low FHR may indicate fetal distress or compromise.

Choice B reason: Maternal pain control is not a direct measure of fetal well-being during labor. However, maternal pain can affect the FHR indirectly by causing maternal stress, anxiety, or hyperventilation, which can alter the blood flow and oxygen delivery to the fetus. Therefore, adequate pain management is important for both maternal and fetal health.

Choice C reason: The response of the FHR to UCs is the most reliable and accurate way of assessing fetal well-being during labor. UCs can cause temporary reductions in the blood flow and oxygen supply to the fetus, which can affect the FHR. A normal response of the FHR to UCs is either no change or a slight increase (acceleration), which indicates a well-oxygenated and resilient fetus. An abnormal response of the FHR to UCs is a decrease (deceleration), which indicates a compromised or hypoxic fetus.

Choice D reason: Accelerations in the FHR are not a definitive measure of fetal well-being during labor. Accelerations are transient increases in the FHR above the baseline, usually caused by fetal movement, stimulation, or UCs. Accelerations are generally reassuring and indicate a responsive and well-oxygenated fetus, but they are not always present or consistent. The absence of accelerations does not necessarily mean fetal distress, as some fetuses may have periods of sleep or reduced activity.