Final answer:
Fetal heart sounds can be detected through auscultation between the 10th and 12th weeks of pregnancy, and septal defects may be identified through unusual heart sounds during this process.
Step-by-step explanation:
Fetal heart sounds are generally retrievable through the process of auscultation, where a healthcare provider uses a stethoscope to listen to the heart. Fetal heartbeats can often be detected for the first time between the 10th and 12th weeks of pregnancy. However, the exact time may vary based on factors such as fetal position, maternal anatomy, and the quality of the equipment used. The detection of these heartbeats is a routine part of prenatal care, as they help in assessing fetal health and detecting any potential septal defects. If unusual heart sounds are heard, indicating a possible septal defect, further diagnosis such as medical imaging or an echocardiogram may be conducted to confirm or rule out any conditions.