How long after conception does the fetal heartbeat begin?

Fetal heartbeat is an important indicator of fetal viability. Around 6-9 weeks of pregnancy, the fetal heartbeat can be observed through ultrasound examination. Its appearance varies from person to person and mainly depends on the menstrual cycle and the implantation timing of the fertilized egg.

For women with regular menstrual cycles, fetal pole and primitive heart tube pulsation—representing the earliest signs of a fetal heartbeat—can generally be detected via ultrasound around 6-7 weeks of pregnancy. This is because under normal circumstances, a certain amount of time is required for the embryo to develop a fetal heartbeat after the fertilized egg implants in the uterus. By 6-7 weeks, the embryonic heart structure has initially formed and begins rhythmic contractions.

However, if a woman has irregular menstrual cycles with frequent delays, ovulation and implantation of the fertilized egg may also be postponed, thereby delaying the appearance of the fetal heartbeat. In such cases, it may not be until 8-9 weeks of pregnancy, or even later, that the fetal heartbeat can be detected via ultrasound. Additionally, certain special conditions, such as delayed embryonic development or ectopic pregnancy, can also affect the timing of the fetal heartbeat's appearance, and may even result in the inability to detect a heartbeat. Therefore, if no fetal heartbeat is detected at the expected time, there is no need for excessive anxiety. Under a doctor's guidance, a follow-up ultrasound can be scheduled after an interval of one to two weeks to dynamically monitor the embryo's development.