What fetal development is generally expected by 12 weeks of pregnancy?

By 12 weeks of pregnancy, one of the significant milestones in fetal development is that fetal heart tones can typically be heard using a Doppler device. At this stage, the heart is fully formed and begins functioning around weeks 5 to 6, but by week 12, it becomes strong enough for detection through Doppler ultrasound technology. This is an important indicator of fetal well-being and can provide reassurance to expectant parents.

At 12 weeks, while there may be early, subtle movements occurring, such as reflexive movements, these are not usually detectable by the mother, as significant fetal movement generally does not occur until later in the second trimester. Similarly, fetal hiccups, if they occur, are not typically detectable until later in pregnancy, and maternal perception of kicking happens towards the 16-25 weeks mark. Thus, option B accurately reflects the expected fetal development at 12 weeks.