There are three main stages of fetal development. The first stage begins before someone discovers they are pregnant, and the last stage ends after delivery. This process is very intricate, and many changes occur daily. This piece highlights some intriguing fetal development facts to help you understand a human being’s gestation period better.

1. A Fetus’s Sex is Developed by Week 2

Within 14 days after the fertilization of the ovum by a sperm, a fetus develops their sex. Their hair, height, eye color, and skin tone are also decided at this stage.

2. The Heart of a Fetus Starts Beating after 22 Days

The heart of a fetus starts beating about three weeks after fertilization. The fetus will have developed all four chambers three weeks from this stage. Additionally, scientists estimate that the heart of an average fetus beats about 54 million times before it is born.

3. A Fetus Can Roll Over in the Amniotic Sac by Week 8

An 8-week-old fetus can roll over in the amniotic sac. However, this doesn’t apply to all fetuses because development differs depending on genes and other factors. Some fetuses take up to 5 months to be able to roll over.

4. At 9 Weeks, a Fetus Can Start Sucking Their Thumb

Babies start sucking thumbs even before they are born. As early as week 7, fetuses start to experience hiccups. They then show signs of breathing by week 8. As they enter week 9, a fetus can sigh and even suck their thumbs.

5. A Fetus’s Body Develops by 75% in Weeks 9 to 10

Between weeks 9 and 10, a fetus’s body grows tremendously by around 75%. It is during this period that the baby bump noticeably increases in size.

6. An Embryo Turns into a Fetus After Week 10

From a medical perspective, an embryo turns into a fetus after week 10. From fertilization to week 10, it’s called an embryo. From week 10 to delivery, that’s called a fetus.

7. At Week 16, A Fetus Can Hear What’s Happening Inside and Outside the Womb

By week 16, most fetuses develop ear structures. Though it’s hardly recognizable for those around or even pregnant women themselves, the womb can be pretty noisy. So, the fetus has to eliminate the unnecessary sounds and listen to the mother’s heartbeat and breathing patterns.

Also, at this stage, the fetus can hear the mother talk. This explains why expectant mothers are encouraged to sing for their babies from week 15 because such sounds can be very soothing.

8. The Eyes of a Fetus Start to Develop at Week 20

The eyes of an average fetus start to grow at week 20. However, they do not open their eyes until they reach week 26 or 27, with the vision being very blurry because of the amniotic sac. However, they can react to light, explaining why most fetuses kick when a flashlight shines on a pregnant mother’s belly.

9. A Fetus Can Taste What an Expectant Mother Eats

As the fetus develops, it prefers some foods because it can taste what the expectant mother eats. The food’s molecules and flavors are transmitted from the mother’s bloodstream into the amniotic fluid. This is partly why some babies prefer certain foods as they grow up because that’s what they were used to in the womb.

10. A Fetus Starts to Touch the Umbilical Cord at Week 22

fetus, placenta, umbilical cord

As the fetus develops, it starts exploring its surroundings after the 6th month. It may touch the umbilical cord and feel some of its prominent features like head or ears. After 22 weeks, a child can be born and survive, although it would be premature. However, they’ll have to be placed in intensive care.

11. A Fetus Brain Develops More Rapidly During the 8th Month

Because nearly all other organs of a fetus have fully developed by the 8th month, the brain kicks into overdrive. As the brain develops, the fetus becomes more aware of its surroundings. An expectant mother can notice when the fetus is awake or asleep.

12. At Week 40, the Fetus Weighs 7 to 9 Pounds

Experts say a healthy fetus should weigh at least 6.5 pounds by week 40. The fetus is ready to be delivered at this stage, and all of its organs are fully developed. The mother will start experiencing signs of labor at this point.

13. A Fetus Can Absorb a Twin During Development

It’s not a myth that a fetus can absorb its twin when still developing in the womb; it is a real condition known as vanishing twin syndrome. Usually, what happens is that when a twin gets miscarried in the womb, the other will absorb their tissue, and so will the mother. The first recorded case of a twin absorbing another was first observed in 1945, but it’s extremely rare.

14. Muslims Believe a Soul Enters the Fetus after 4 Months

According to the Quran, God sends an angel to breathe a soul into a fetus 40 days after conception. Before that duration, it is a mere living organism without a soul.

Categorized in:

Humans, Science,

Last Update: March 15, 2024