A client at 12 weeks gestation attends a class on fetal development. The nurse anticipates that at 16 weeks' gestation the fetus will have:

• A. Have fetal movements readily felt by the mother.
• B. Be able to hear sounds outside the uterus.
• C. Be fully formed at birth.
• D. Have audible heart sounds.

Answer: (D)

Key idea: By around 16 weeks, the fetal heart can be detected audibly with a Doppler, reflecting early fetal cardiovascular activity. Doppler devices can pick up heart tones as early as 10–12 weeks, so at 16 weeks the heartbeat is typically readily audible. Movement by the mother (quickening) usually isn’t felt until about 18–20 weeks, so it wouldn’t be expected to be readily felt at 16 weeks. Fetal hearing of external sounds develops later, around the second trimester, and the fetus is not fully formed at 16 weeks; organs and structures continue to mature after this point. Therefore, hearing the fetal heartbeat at 16 weeks is the most consistent finding.