A nurse is teaching a client who is at 15 weeks of gestation and is to undergo an amniocentesis. The nurse should explain that the purpose of this test is to identify which of the following conditions? (Select all that apply.)

Explanation:

A. Rh incompatibility

Amniocentesis is not used to identify Rh incompatibility. Rh incompatibility occurs when the mother is Rh-negative, and the baby is Rh-positive, leading to potential complications if the mother develops antibodies against the baby's Rh-positive blood cells. However, this condition is typically managed through other means such as Rh immunoglobulin (RhIg) administration.

B. Fetal gender

Amniocentesis can determine the fetal gender by analyzing the chromosomes present in the fetal cells obtained from the amniotic fluid. The presence of a Y chromosome indicates a male fetus, while its absence indicates a female fetus. Therefore, fetal gender can be identified through amniocentesis.

C. Cephalopelvic disproportion

Cephalopelvic disproportion refers to a situation where the baby's head is too large to pass through the mother's pelvis during childbirth. This condition is typically diagnosed during labor based on the progress of labor and fetal descent. Amniocentesis is not used to identify cephalopelvic disproportion.

D. Anomalies in fetal chromosomes

Amniocentesis is primarily used to identify anomalies in fetal chromosomes, such as chromosomal abnormalities like Down syndrome (Trisomy 21), Trisomy 18, and Trisomy 13. It can also detect other chromosomal abnormalities and genetic disorders caused by changes in the number or structure of chromosomes.

E. Neural tube defects

Amniocentesis can detect neural tube defects, such as spina bifida and anencephaly, by analyzing levels of alpha-fetoprotein (AFP) and other markers in the amniotic fluid. Elevated levels of AFP may indicate a neural tube defect.

Explanation:

A. Slightly below the umbilicus:

Around 16-20 weeks of gestation, the fundal height is typically palpated slightly below the umbilicus. This corresponds to the level of the fundus before it starts rising significantly above the umbilicus as the pregnancy progresses.

B. 3 cm above the umbilicus:

At 22 weeks of gestation, the fundal height is expected to be approximately 3 cm above the umbilicus. This is a common estimation for the fundal height at this stage of pregnancy, as the uterus continues to grow and the fundus ascends in a predictable manner.

C. 3 cm below the umbilicus:

Palpating the fundus 3 cm below the umbilicus would typically correspond to an earlier gestational age, such as around 16-18 weeks. As pregnancy advances, the fundal height increases, and by 22 weeks, it should be well above the level of the umbilicus.

D. Slightly above the umbilicus:

This location is closer to where the fundal height is expected to be at later gestational ages, such as 24-26 weeks. However, at 22 weeks of gestation, the fundal height should not be palpated slightly above the umbilicus but rather around 3 cm above it.