Which medication is commonly used to treat juvenile idiopathic arthritis (JIA)?

Choice A rationale

This choice is incorrect because Naegele's Rule involves adding seven days to the first day of the last menstrual period and then subtracting three months. Starting with September 17, adding seven days yields September 24. Subtracting three months from September 24 results in June 24, which is not the correct estimated delivery date according to the rule.

Choice B rationale

This choice is incorrect because applying Naegele's Rule requires a precise calculation. If the first day of the last menstrual period was September 17, adding seven days gives September 24. Subtracting three months from September 24 would result in June 24, not June 10, thus indicating an error in calculation for this option.

Choice C rationale

This choice is incorrect as it does not align with the application of Naegele's Rule. The rule specifies adding seven days to the LMP and subtracting three months. Starting from September 17, adding seven days brings it to September 24. Subtracting three months from September 24 mathematically leads to June 24, making June 20 an inaccurate calculation.

Choice D rationale

This choice is correct because Naegele's Rule is applied by adding seven days to the first day of the last menstrual period and then subtracting three months. With a last menstrual period of September 17, adding seven days results in September 24. Subtracting three months from September 24 accurately yields June 24 of the following year as the estimated date of delivery.

The nurse should determine that the FHR pattern represents Early decelerations due to Fetal head compression during contractions.

Rationale for correct answers:

Early decelerations are a gradual decrease and return to baseline of the fetal heart rate (FHR) associated with uterine contractions. They mirror contractions, beginning and ending with the contraction. This pattern is physiologic and typically benign.

Fetal head compression during contractions causes a vagal response leading to early decelerations. At a station of +4 and full dilation, fetal descent is significant, making head compression the most likely cause.

Rationale for incorrect Response 1 Options:

Late decelerations occur after the peak of the contraction and are due to uteroplacental insufficiency. These are non-reassuring and do not mirror contractions, unlike what is noted in the case.

Variable decelerations are abrupt drops in FHR and vary in timing, shape, and duration. They are not mirror images and are often associated with cord compression, which is not supported by this case’s findings.

Prolonged decelerations last >2 minutes and <10 minutes. The decelerations in this case are transient (to 105 bpm) and resolve before the end of the contractions, ruling out prolonged patterns.

Rationale for incorrect Response 2 Options:

Umbilical cord compression leads to variable decelerations, which are abrupt and not aligned with contraction timing, unlike the current pattern.

Uteroplacental insufficiency results in late decelerations, which occur after the contraction ends. These are non-reassuring and not consistent with the current findings.

Maternal hypotension due to epidural could cause late decelerations from reduced placental perfusion. However, despite a BP drop at 0900 (100/52 mm Hg), the FHR deceleration pattern does not match.

Take home points:

• Early decelerations are benign and typically reflect fetal head compression during contractions.
• Differentiate early from late decelerations based on timing relative to contractions—early mirrors, late lags.
• Variable decelerations are abrupt and typically linked to umbilical cord compression, not head compression.
• Maternal hypotension from epidural requires close monitoring, but it leads to uteroplacental insufficiency and late decelerations, not early.