downs syndrome is caused by

HESI LPN

HESI Maternal Newborn

1. What causes Down's syndrome?

A. Alcohol abuse by the mother at the time of conception.
B. Sex-linked chromosomal abnormalities.
C. An extra chromosome on the 21st pair.
D. Drug abuse by the mother during pregnancy.

Correct answer: C

Rationale: Down's syndrome, also known as trisomy 21, is caused by the presence of an extra chromosome on the 21st pair. Choice A is incorrect as alcohol abuse is not the cause of Down's syndrome. Choice B is incorrect because Down's syndrome is not related to sex-linked chromosomal abnormalities. Choice D is also incorrect as drug abuse by the mother during pregnancy is not the cause of Down's syndrome.

2. A 38-week primigravida is admitted to labor and delivery after a non-reactive result on a non-stress test (NST). The nurse begins a contraction stress test (CST) with an oxytocin infusion. Which finding is most important for the nurse to report to the healthcare provider?

A. A pattern of fetal late decelerations.
B. Fetal heart rate accelerations with fetal movement.
C. Absence of uterine contractions within 20 minutes.
D. Spontaneous rupture of membranes.

Correct answer: A

Rationale: The correct answer is A: A pattern of fetal late decelerations. Late decelerations during a contraction stress test are concerning as they indicate uteroplacental insufficiency, which can pose a risk to fetal well-being. Reporting this finding to the healthcare provider is crucial for prompt intervention. Choice B, fetal heart rate accelerations with fetal movement, is a reassuring sign of fetal well-being and does not raise immediate concerns. Choice C, absence of uterine contractions within 20 minutes, may require further assessment but is not as critical as late decelerations. Choice D, spontaneous rupture of membranes, is important but not the most immediate concern during a contraction stress test.

3. A client tells the nurse that she thinks she's pregnant. Which signs or symptoms provide the best indication that the client is pregnant?

A. Morning sickness.
B. Breast tenderness.
C. Amenorrhea.
D. Hegar's sign.

Correct answer: D

Rationale: Hegar's sign, which is a softening of the lower uterine segment, is considered a probable sign of pregnancy as it indicates changes in the cervix and uterus that occur during pregnancy. Amenorrhea, the absence of menstruation, is a common early sign of pregnancy but can also be due to other factors. Morning sickness, nausea and vomiting, can be a sign of early pregnancy but is not as specific as Hegar's sign. Breast tenderness is a common symptom in early pregnancy due to hormonal changes, but it is not as definitive as Hegar's sign in indicating pregnancy.

4. A client at 38 weeks of gestation has a prescription for intravaginal misoprostol. Which of the following statements should the nurse make?

A. “You will need to stay in a side-lying position for 30 minutes after each dose.”
B. “You will receive an IV infusion of oxytocin 1 hour after your last dose.”
C. “You will receive a magnesium supplement immediately following therapy.”
D. “You will need to have a full bladder before the therapy begins.”

Correct answer: A

Rationale: The correct answer is A. Instructing the client to stay in a side-lying position after receiving misoprostol intravaginally is essential. This position helps keep the medication in place, allowing for better absorption. Choice B is incorrect because oxytocin administration is not typically indicated after misoprostol use. Choice C is incorrect as magnesium supplementation is not part of the standard protocol for misoprostol administration. Choice D is incorrect as having a full bladder is not necessary before initiating misoprostol therapy.

5. Genotypes are solely based on genetic information.

A. TRUE
B. FALSE
C. Sometimes
D. Never

Correct answer: B

Rationale: The correct answer is B - FALSE. Genotypes are solely based on genetic information and do not reflect environmental influences. Phenotypes, on the other hand, result from the interaction of genetic and environmental factors. Choices A, C, and D are incorrect because genotypes are not influenced by environmental factors, and they are determined by an individual's genetic makeup.