Do you know what a fetus looks like inside the womb? How does it move throughout the entire pregnancy? Every mother must be curious about these questions. Let's explore what a fetus looks like inside the womb! After conception, the fetus begins rapid growth inside the mother's belly. Do you want to know what changes it undergoes? What does a fetus look like inside the womb?
0–2 Weeks — The Egg
When does pregnancy officially begin? Obstetricians calculate it from the mother's last menstrual period. But in reality, during the first week of pregnancy, the egg and sperm haven't yet combined.
The egg cell remains dormant within the ovary as a follicle, while the uterus—the future cradle for embryonic development—continues growing and preparing for conception.
By the second week, one egg matures within the ovary and travels into the fallopian tube, awaiting the arrival of sperm.
The egg can survive in the fallopian tube for about 24 to 36 hours. During this period, if intercourse occurs, hundreds of millions of sperm will swim toward the egg. Ultimately, only one lucky sperm will successfully unite with the egg, forming a fertilized egg.
At this moment, a new life begins.
1 Month — I'm a Tiny Grain of Millet
The fertilized egg travels down the fallopian tube into the uterus, where it implants into the uterine wall and begins its formal growth and development stage.
At this stage, the embryo is still a cluster of cells composed of two layers of tissue. These two layers will eventually develop into all the tissues and organs of the fetus.
How big is a 1-month-old fetus? About the size of a grain of rice.
During this period, the fetus's brain, spine, and heart gradually begin to develop. Although not yet fully formed, their basic shapes are beginning to take shape.
2 Months — Fetal Heartbeat Detected
At two months, the fetus is about the size of a sunflower seed.
The embryo now resembles a human form, with discernible outlines of eyes, ears, and mouth on the face. Fingers and toes begin to appear on the limbs.
By two months, the fetal heart has formed and begins to beat.During an ultrasound, you may see the fetal heart beating.
3 Months — The Fetus Begins Moving Arms and Legs
At three months, the fetus is about the size of a small lemon.
By this stage, the most critical developmental phases are complete. Internal organs have settled into their designated positions and begun growing.
During this stage, the fetus's bones begin to harden, and its limbs can move involuntarily.
The uterine space is relatively spacious now, allowing the fetus to move freely in the amniotic fluid. However, these movements are still very subtle and undetectable to the mother.
4 Months — The fetus can make gestures
At 4 months, the fetus is about the size of a mango.
During this stage, they can suck and yawn, which may be visible during an ultrasound.
The fetus's limbs continue to develop, allowing their hands to perform more intricate movements like opening, clenching fists, and even making gestures.
During this period, the fetus becomes highly active, changing positions frequently. Most mothers begin to feel the baby's movements in the womb for the first time—known as fetal movements.
Additionally, as the external genitalia develop, their appearance becomes increasingly distinct. The fetus's gender can now be determined via ultrasound.
5 Months — The Fetus Can Hear Sounds
At 5 months, the fetus's head is about the size of a kiwi fruit, with a body length of approximately 25 cm and a weight of around 250 g (roughly half a pound).
During this period, the fetus's facial features develop rapidly, capable of complex expressions like frowning or smiling.
With the maturation of auditory organs, the fetus can now hear sounds from within and outside the mother's body. Expectant parents can speak gently to the belly—the baby can feel your love.
Starting this week, the fetus enters a phase of rapid weight gain—the belly grows noticeably larger from being barely visible before, and fetal movements become significantly more frequent.
6 Months — Fetal Sleep Patterns Become More Regular
At 6 months, the fetus's head is about the size of a pear, with a body length of approximately 30 cm and a weight of around 600 g (just over 1 pound).
At this stage, the fetus begins to resemble a newborn, with all organs developed. However, as subcutaneous fat deposits just start forming, the skin appears wrinkled.
Additionally, the fetus's sleep rhythms gradually develop, and their movements become more regular in sync with sleep cycles.
7 Months — Increased Fetal Activity
At 7 months, the fetus's head is about the size of an orange, with a body length of 35 cm and a weight reaching 1000 g (approximately 2 pounds).
From now until birth, the fetus's weight will increase 4 to 5 times.
By this stage, the fetus has grown large enough to fill the entire uterine cavity, allowing the mother to feel its movements more distinctly.
Compared to earlier stages, fetal movements become more frequent and responsive to external sounds. Sometimes, tiny hands or feet create little bumps on the mother's belly.
Additionally, the fetus develops more senses: eyes can open to perceive light and color, while nasolabial and gustatory senses emerge, allowing the baby to experience this new world.
With luck, an ultrasound might even capture the baby blinking its eyes.
8 Months — Baby's Skin Turns Pink
At 8 months, the baby's head is about the size of a pomelo, measuring roughly 40 cm in length and weighing approximately 1700 g (around 3.5 pounds).
The fetus's body is largely developed, though the lungs still need more time. If born suddenly during this period, they are prone to neonatal respiratory distress syndrome.
Their body continues to grow, but due to limited space in the uterus, fetal movements become less frequent.
The fetus's skin changes from translucent to pink, and as subcutaneous fat accumulates, the body becomes plumper.
9 Months — Fetus Enters Pelvis
At 9 months, the fetus's head is about the size of a pomegranate, with a body length of approximately 45cm and a weight of around 2500g (about 5 pounds).
During this period, all the fetus's organs, especially the lungs, continue to mature in preparation for birth.
After 9 months, the fetal position stabilizes as the baby gradually descends into the mother's pelvis, preparing for birth.
10 Months — The Baby Wants Out
By 10 months, the fetus is fully matured with rosy skin and ample subcutaneous fat. It possesses good breathing and sucking abilities, ensuring strong postnatal viability.
Most babies are born around 39 weeks, so mothers should be prepared for labor to begin at any time during this period.
Additionally, before labor starts, mothers should closely monitor fetal movements. If abnormalities occur—such as sudden increased activity or a complete absence of movement—seek medical attention promptly to prevent fetal hypoxia.