The nurse is interviewing a client who is pregnant in her first trimester, and the client inquires about their gestational age. The nurse understands which assessment will provide the most accurate gestational age?

Choice A rationale

Ultrasonography provides the most accurate assessment of gestational age, especially in the first trimester, by measuring the crown-rump length.

Choice B rationale

HCG levels can indicate pregnancy but are not as accurate for determining the exact gestational age.

Choice C rationale

Nagele's rule is based on the menstrual cycle and may not be accurate if cycles are irregular.

Choice D rationale

Fundal height measurement is less accurate in early pregnancy and more useful in later trimesters.

Choice A rationale

Enlarged uterus is a probable sign of pregnancy, often caused by uterine growth. Probable signs are those observed by the examiner but not definite.

Choice B rationale

Positive fetal cardiac activity on ultrasound is a positive sign of pregnancy. Positive signs are definitive proof of pregnancy, observed via imaging or hearing fetal heart tones.

Choice C rationale

Auscultation of fetal heart tones is a positive sign of pregnancy, indicating fetal presence. Positive signs confirm pregnancy through direct observation or hearing the fetus.

Choice D rationale

Amenorrhea is a presumptive sign of pregnancy, commonly due to hormonal changes. Presumptive signs are subjective symptoms experienced by the woman, like nausea or breast tenderness.