You’ve just found out that you’re pregnant, and are just starting to prepare for the pregnancy stages ahead of you. But what does really happen in there, and how does your baby develop over the course of the upcoming 40 weeks?
The following lines will show you the stages of pregnancy week by week.
Week 1 and 2
Even if your doctor starts counting from the start of your last period, you aren’t actually pregnant in the first two weeks. During the first two weeks your body will develop and grow a mature egg which will prepare for fertilization.
Week 3 (Fertilization)
Your body has just released one or two mature egg during ovulation, and now fertilization can occur. Once an egg is fertilized by sperm, it will become a zygote and start traveling down the fallopian tubes and towards the uterus while its cells are starting to divide.
Week 4 (Implantation)
The zygote is now a blastocyst, or a small ball of rapidly dividing cells. Once it reaches the uterus, it will implant itself on the uterine wall. The interior of the blastocyst will become the embryo, while the outer layer will serve to nourish and protect it, and this is also when the placenta forms.
This is the start of the embryonic period, where the embryo starts undergoing major changes. The brain, spinal cord, heart and all important organs are beginning to form, and the embryo is the size of a pen tip.
The neural tubes are closing, and the facial features are starting to appear. Your baby is now shaped as a C, and small buds are appearing which will develop into its arms and legs.
The baby’s brain develops even further, and the facial features become more noticeable, with small nostrils and eye lenses appearing. The small buds are now shaped like small paddles.
The baby’s arms and legs become longer and developing fingers can be seen. The eyes are more visible, and the outer ears are starting to form. The nose and upper lip are also forming, and the C-shape is beginning to straighten, now measuring around half an inch.
Bones form in the arms and legs, and small toes appear. The small ears and eyelids are defining more and more, and the baby’s body is ¾ inches long or 2 cm.
The baby’s head is rounder, and the neck is visible. The eyelids are closing in order to protect the eyes which are developing.
The baby is now a fetus, measuring 2 inches or 5 cm and weighing 1/3 pounds or 350 g. Its external genitals are forming, and the liver has begun to produce red blood cells.
By now fingernails are forming, and the facial features become “more human”. The baby now measures 2 ½ inches or 6 ½ cm and weighs ½ pounds or 225 g.
The precursors of your baby’s bones start to form around the head and inside the arms and legs. The intestines return to the abdomen from the umbilical cord and urine starts being produced.
The baby’s sex becomes more apparent, and the arms are nearing their final relative length. The prostate forms for boys and ovarian follicles for girls.
The baby’s forming bones are just a few weeks from being seen on ultrasound, and the scalp pattern is forming.
Your baby’s movements can be seen on ultrasound images, and they’re getting more coordinated. You can even see the baby doing sucking motions with its mouth.
The baby starts forming fat tissue under the skin, which will be important after birth and help it keep warm.
Your baby’s ears are standing on both sides of the head, and he can probably hear by now.
The vernix caseosa, a protective greasy layer, forms around the baby. For girls, the uterus and vagina also starts to form.
About at the half of the pregnancy duration, you will probably start to feel your baby’s movements.
The baby is increasingly active and he can now swallow too.
Your baby becomes covered in fine hair which helps keep the vernix in place. The eyebrows are also forming right now.
The baby is showing rapid eye movements, his fingerprints form, and the boy’s testes descend from the abdomen. The girls’ uterus and ovaries are where they should be.
The baby is beginning to sleep and awake, and his real hair is beginning to form.
The baby’s reflexes and hand movements are improving and the might also be able to respond to your voice.
The baby’s fingernails are completely grown, and its lungs are producing the substance which will keep them inflated from now on.
Your baby’s nervous system and lungs are not fully developed but are continuing to grow. The baby is entering the third stage of pregnancy.
The eyelids of your baby are starting to open, revealing the eyes. Babies born now have a 90% chance of survival.
Your baby’s bones have developed completely, although they’re still soft.
Your baby can now open his eyes wide open (except when he’s sleeping, of course).
The central nervous system is fully mature, and it can now regulate body temperature.
Your baby is learning how to breathe, although the lungs are not fully developed yet.
The pupils of your baby’s eyes can constrict and dilate, which means he can now detect light.
The fingernails reach the baby’s fingers, and he now measures 12 inches or 30 cm.
The baby is putting on weight at an accelerating rate, gaining almost half a pound per week.
Your baby finds it harder to punch or move, although he can still roll, wiggle or stretch.
You can now consider your baby full term, and its head is starting to descent, preparing for birth.
Your baby has a firm grasp by now, and weighs about 6 ½ pounds or 3 Kg.
The placenta offers the baby the antibodies it will need after birth.
Your baby is ready for arrival! So prepare yourself to give birth and welcome the newcomer into our world!