-
#1 The Last Menstrual Period
The official start of pregnancy is the first day of bleeding. The forty weeks of pregnancy are numbered from this day. -
#2 Fertilization
3-10 eggs receive hormonal signals that enable them to mature and prepare for ovulation. In the next 36-48 hours, one sperm will go through the fallopian tube to penetrate the egg and fertilize it. -
#3 Cells Join, Divide, and New Life Begins
The fertilized egg quickly begins to divide and floats down in to the uterus, containing all of the DNA necessary to determine the physical characteristics of the future child. The embryo moves into the uterus about 80 hours after ovulation and the implantation process starts 3 days later. -
#4 Implantation
The fertilized egg is now a blastocyst, filled with fluid and 50 to 60 cells that are constantly multiplying. The developing embryo is one hundredth of an inch long so far, and the site of implantation is where the placenta will attach to the uterine wall. The blastocyst will start to release human gonadotrophin hormone (hCG). -
#5 The Embryonic Stage Commences
The blastocyst is divided into forming the placenta and the other will be the baby.The embryo, inside the placenta, will grow to more than double its' size to around 4 to 5 millimeters. -
#6 The Embryo's Heart Beats
The embryo is smaller than a raisin but the ears are starting to form, as well as all the main body organs and systems. The heart begins to beat on the 25th day after the last day of menstration. -
#7 The Arms and Legs Are Forming
The embryo's size is now around 13 millimeters long and one chamber of the heart is beating. The navel string is starting to grow along with the embryo's arms and legs from buds at each side of the tiny body. -
#8 Movement
The pituitary gland starts to develop and muscle fibers are growing. The embryo is about 18 millimeters long. Its heart has grown another chamber and is now beating 150 beats per minute. -
#9 The Fingers and Toes Grow
The embryo has grown to 30 millimeters long. The baby's head seems bigger than the body because the brain is developing. Fingers and toes are forming but are still in a web-like structure.The heart is complete in its formation and the ears and teeth are still developing. -
#10 Fetus
The embryo is now termed a fetus after the ninth week and is the size of a small strawberry. Fingerprints can be seen on the skin and testicles or ovaries are on their way to form. -
#11 Multiplying Neurons
The fetus is about 1.5 inches big and the cartilage is now starting to calcifu to become bone. The brain is growing faster and creating more then 250,000 nerve cells per minute. -
#12 We See Fingernails and Toenails
The fetus is now 2.5 inches long and moves at random times. Its heart rate is now up to 160 beats per minute.The brain is fully formed and the fetus can start to feel pain. The hair is seen on the head and the fingers and toes start to form tiny fingernails. -
#13 More Movement from the Baby
The fetus is now 3 long with its nose and chin well-structured. The genitalia are formed to the point where it may be possible to determine the sex. Insulin is also being produced within the baby and can flex the arms and kick its legs. -
#14 Hormones
The fetus is 3 and a half inches long and its kidneys are producing urine.The hormones within the body enable the fetus' ovaries or testes to move and develop further. -
#15 Muscles and Bones
The baby is over 4 inches long, weighs around 2.5 ounces, and its muscles and bones continue to develop. He/she now has the tastebuds of an adult and could be able to savor the mother's meals. -
#16 Baby Can Make Facial Expressions
The fetus weighs about 3.5 ounces and is around 5 inches long.By this point, it has learned how to breathe (small amounts of amniotic fluid), and can hear external voices, can sleep and even dream. -
#17 Fat Gathers Up
The fetus weighs about over 5 ounces and is still 5 inches long. The first feces are starting to accumulate within the body. The fat is beginning to store as well to provide energy and keep the baby warm. -
#18 Hearing
The fetus is 6 inches long and weighs 7 ounces. It starts to hear the mother's heart beating, stomach growling, and/ or the blood moving through the umbilical chord. Small alveoli also begin to grow in the baby's lungs and the vocal chords are now formed. -
#19 The Sex Is Known
The fetus is about 6.5 inches and weighs around 9 ounces. The genitals are recognized and clear to see. The baby's muscles and bones are getting strong enough to kick around. -
#20 Halfway There!
This week marks halfway through the pregnancy where the baby now weighs about 11 ounces and is 7 inches long. This is a crucial time for the development of the five senses: taste, smell, hearing, sight, and touch. -
#21 Nourishment
The baby is about 10.5 inches and 12.7 ounces in weight. The small body's bone marrow is producing blood cells. Small amounts of glucose are starting to get absorbed from the amniotic fluids within the sac for nourishment and energy. -
#22 Continued Development of Tastebuds
The baby is 28 centimeters long, measure from crown to heel, and weighs more than 450 grams. The baby's tastebuds are continuing to develop on the tiny tongue. -
#23 Development of Balance
The baby measures in over 28 centimeters and weighs about 550 grams (a bit over a pound). He/she keeps moving more and more inside the womb. The indicated skin color is taking over the baby's body that is now structured to look like a newborn. -
#24 Development of the Lungs
The baby is seen weigh about 1.3 pounds and is 12 inches long. If he/she is born around this week, it is considered viable and may have a chance of survival.The lungs are producing branches and cells for the developing respiratory system. -
#25 Spine and Hand Development
The baby is about 34 centimeters long and weighs almost 690 grams. The structures of the spine start to mold. Swallowing reflexes, blood vessels of the lungs, and the tiny hands are developing.
