The nurse is explaining to a student how to assess a client via internal fetal monitoring.
What would the nurse include as characteristics of this practice? Select all that apply.

Choice A rationale

Ultrasound (US) technology is instrumental in assessing the placenta, providing details on its location (e.g., fundal, anterior, posterior) and ruling out conditions like placenta previa, where the placenta covers the cervical opening. It can also estimate the overall size and maturity of the placenta, aiding in the assessment of uteroplacental function and fetal nutrient supply.

Choice B rationale

The amniotic fluid index (AFI) or single deepest pocket measurement, quantified via ultrasound, provides an estimate of the amount of amniotic fluid surrounding the fetus. Abnormal amounts, such as polyhydramnios (excess fluid) or oligohydramnios (low fluid), are associated with various fetal and maternal complications, requiring further monitoring and management.

Choice C rationale

Fetal reactivity is primarily assessed using a non-stress test (NST), which monitors the fetal heart rate (FHR) response to fetal movement using an external tocodynamometer and Doppler transducer. While ultrasound can visualize fetal movement, it is not the standard or primary tool for evaluating fetal reactivity as defined in a formal biophysical profile or NST.

Choice D rationale

Ultrasound is not a definitive diagnostic tool for chromosomal abnormalities such as Down syndrome (Trisomy 21) or Edwards syndrome (Trisomy 18). However, US can identify "soft markers" or structural anomalies (e.g., increased nuchal translucency, heart defects) that suggest an increased risk, which would then necessitate definitive diagnostic testing like amniocentesis or chorionic villus sampling (CVS).

Choice E rationale

Fetal biometry, performed through ultrasound, involves measuring structures like the biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL). These measurements are used in mathematical formulas to estimate fetal weight and determine gestational age, especially when the date of the last menstrual period is uncertain.

Choice F rationale

Ultrasound can visualize the external genitalia of the fetus, allowing for the determination of the fetal gender. The accuracy of this determination is highly dependent on the gestational age of the fetus and the position of the fetus during the examination, with accuracy generally increasing in the second trimester and beyond.

Choice A rationale

At 20 weeks gestation, the uterine fundus typically reaches the level of the umbilicus (navel). This standardized landmark is due to the uterus's growth pattern, where it rises out of the pelvis and becomes an abdominal organ. Measuring fundal height from the symphysis pubis to the top of the fundus, it usually correlates with the weeks of gestation ± 2 cm between 18 and 32 weeks, making 20 cm at the umbilicus the expected finding.

Choice B rationale

Two finger-breadths below the umbilicus corresponds to approximately 18 weeks gestation. Before 20 weeks, the fundus is lower in the abdomen as the uterus continues its upward expansion from the pelvic cavity. At this stage, the measurement would be slightly less than 20 cm, indicating a smaller uterine size than expected for a 20-week pregnancy.

Choice C rationale

Halfway between the symphysis pubis and the umbilicus indicates a fundal height consistent with approximately 16 weeks gestation. At this point, the uterus is palpably in the abdomen, but its superior edge is still significantly lower than the umbilicus. This position reflects earlier growth before the rapid ascent to the umbilicus at 20 weeks.

Choice D rationale

Fundal height at the level of the xyphoid process is expected around 36 weeks gestation as the uterus reaches its highest point in the abdomen. This significantly higher position reflects a near-term pregnancy, where the large fetus and uterus displace the abdominal contents superiorly toward the diaphragm, much later than 20 weeks.