A nurse is teaching a new parent how to correctly use a car seat.
Which of the following statements by the parent indicates an understanding of the teaching?

Choice A rationale

Fetal cardiac activity is typically detectable via transvaginal ultrasound as early as 5.5 to 6 weeks gestational age, when the embryo is approximately 2-4 mm in crown-rump length. However, hearing the heartbeat with a Doppler stethoscope usually occurs later, around 10 to 12 weeks, as the fetal heart is still very small and sound transmission is limited.

Choice B rationale

The standard schedule for prenatal visits involves monthly appointments from the first prenatal visit until 28 weeks of gestation. This frequency allows for consistent monitoring of maternal and fetal well-being, early detection of potential complications, and timely interventions. After 28 weeks, visits typically become more frequent.

Choice C rationale

While a complete blood count (CBC) is a crucial laboratory test performed during pregnancy, it is not typically done at every prenatal visit. Initial CBCs are obtained at the first prenatal visit to establish baseline values, and then repeated later in pregnancy, often around 28 weeks, to screen for anemia and other hematologic changes.

Choice D rationale

Screening for neural tube defects, often through maternal serum alpha-fetoprotein (MSAFP) testing, is typically performed between 15 and 20 weeks of gestation. This timing is crucial for accurate interpretation of results and allows for further diagnostic evaluation if abnormalities are detected, well before 32 weeks.

Choice A rationale

Meconium stools are a normal physiological finding in a newborn during the first 24-48 hours of life. This thick, tarry, dark-green stool is composed of intestinal epithelial cells, amniotic fluid, bile, and water, reflecting fetal gastrointestinal tract development and function. Its presence indicates typical bowel activity.

Choice B rationale

Depressed fontanels indicate dehydration in a newborn. The fontanels are soft spots on a baby's head where the skull bones have not yet fused. When a baby is dehydrated, the fluid volume in the brain decreases, causing the fontanel to appear sunken below the normal contour of the skull, which necessitates immediate medical attention due to potential complications.

Choice C rationale

Rust-stained urine, also known as "brick dust" urine, in a newborn can indicate dehydration. This discoloration is caused by the excretion of urate crystals, which are a normal metabolic byproduct. However, in concentrated urine, these crystals become more visible, suggesting insufficient fluid intake and requiring further assessment to prevent significant dehydration.

Choice D rationale

Overlapping suture lines, also known as molding, are a common and expected finding in newborns, especially after vaginal delivery. This temporary reshaping of the fetal skull allows it to pass more easily through the birth canal and typically resolves spontaneously within a few days as the brain grows and fills the cranial cavity.