Baby’s development in the womb

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Baby’s development from conception to birth is a most incredible adventure. How, in nine months, does an egg, born from the union of a sperm and an oocyte, become an embryo, then a foetus and then a baby? This is what we invite you to discover below.


Fertilization results from the fusion of a cell from the father, the sperm cell, with a cell from the mother, the oocyte.These two cells thus become one: the egg. In three days the egg reaches the uterus: this is called implantation. On the seventh day it adheres to the wall of the uterus. It then measures only 1/10th mm.

The first month

The egg develops rapidly. It gradually becomes an embryo. Its little heart produces something resembling a beat. Tiny buds, its future limbs, appear. It measures 5 mm and looks like a tiny tadpole. Worth knowing: while the egg is at first a single cell, it will not stay that way for long. In the hours and days after fertilization, it divides into 2, then 4, 8, 16 cells. At the time of birth, baby has about sixty thousand billion cells. An extraordinary development that owes much to you !

The second month

The arms and legs grow longer and facial shapes become clearer. Huge mouth, flattened nose and disproportionate eyes – this dear little being changes very quickly. The organs and skeleton become established. The umbilical cord and placenta are now providing vital exchanges. Worth knowing: at the end of the second month, all the organs are well advanced in beginning to form. Your future baby has accomplished the bulk of its work.

The third month

Your baby goes from the embryo stage to the foetus stage. The organs are perfected, the genitals of your child start becoming established and the face changes and shapes itself. The brain begins to form in three structures and gradually, the nervous system communicates with the muscles.

Le quatrième mois

This is an intense period of development: all the organs are in place and begin to work. Nails and hair start to grow. Baby is a real human child. His heart beats around 140 times per minute, twice faster than yours. Some of you are beginning to feel baby’s first movements. Worth knowing: baby is covered with a fine down, lanugo down, and a coating, vernix caseosa, which protect the skin from the amniotic fluid.

The fifth month

Baby’s gender is now clearly determined. His life becomes organised and his activity is intensifying. He moves more and more. His senses develop and his sensitivity to the external environment increases. He swallows amniotic fluid which he can now digest and his mouth seeks his thumb. Worth knowing : do not hesitate to connect with baby. Lie down comfortably and put your hand on your belly. You will feel him move close to it. You can share these moments with dad.

The sixth month

Baby is very active. He still has enough space and takes advantage of it. He makes 20 to 60 movements per half hour, a real little acrobat! His senses are well developed. His ears finish forming and he can hear you properly now. He reacts to your words and caresses and those of dad.

The seventh month

Baby’s senses awaken. He opens his eyes and, even if he cannot see, he reacts to strong changes of light. All his vital organs are functioning now. He begins to develop his respiratory system and thus prepares himself for life by your side. Due to lack of space, he limits his movements.

The eight month

Baby takes his final position: this is the one he will have at the time of birth. The ideal position is to have his little head against the cervix. His bones are growing and they absorb a lot of calcium. On approaching childbirth, you feel apprehensive and this is normal. Talk about it to the professionals who are supporting you. Antenatal classes are good opportunities to network with other mums.

The ninth month

Baby is finally ready to show himself. His organs are functional and his lungs are ready for breathing. He has lost the fine down that was covering him and his skin has become smooth and slightly pinkish. He gains 20 to 30 g per 24 hours and every passing day makes him stronger for discovering his future world.Worth knowing: the skull bones are not yet fused so baby’s head can easily adapt to the physical constraints of childbirth.