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First Day of Last Period
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Period: to
Gestation
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Period: to
Proliferative Phase
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Ovulation, Proliferative Phase Ends
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Fertilization
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Period: to
Luteal Phase
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Period: to
Month One
Size is about 1/4 of an inch long. Fetus is made up of three layers- ectoderm, mesdoderm, and endoderm that will eventually form different body systems. The ectoderm develops into the epidermis, nervous tissue, and sensory organs. The mesoderm develops into connective tissue, muscle, bone, and the urogenital and circulatory system. The endoderm develops into the gastrointestinal tract, the lungs, and associated structures. -
Morula Stage
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Blastocyst
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Implantation, Placenta Begins to Form
The primary purpose of the placenta is to provide the fetus with nourishment, eliminate its wastes and exchange respiratory gases. -
Brain Begins to Form, Embryonic Phase Starts
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Heart Is Functioning, The Neural Tube Begins to Close
The neural tube will eventually form the spinal cord. At this point basic facial features are also beginning to develop. The digestive tract has also begun development, as well as the spine. -
Period: to
Month Two
Size at the end of this month should be around 1 and 1/8 of an inch. In boys, gender also starts to become visually distinguishable. -
Arm and Leg Buds Form
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Back Begins to Straighten Out from the C-Shape
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Bones Are Developing
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Fingers and Toes are Visible, but Webbed
Lungs are mostly developed but still not functioning yet. -
Period: to
Month Three
Size at the end of this month should be about 2.5 to 3 inches and .5 to 1 ounces. The heart rate can be heard with specialized instruments. -
Has All Essential Organs and Tissues
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Arms, Legs, Fingers and Toes are Fully Developed
Includes hands and feet. -
First Trimester Ends
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Month Four
Size at the end of this month should be about 6.5 to 7 inches long and about 6 to 7 ounces. -
Reflexes like sucking and swallowing are developing
Skin is covered by a layer of hair. -
Period: to
Month Five
Size at the end of this month should be around 10 inches and 1 pound. Movement can sometimes begin to be felt in this month. Lanugo coats the fetus's body. Hair, eyebrows, eyelids, and eyelashes begin to appear. -
Fat Storage Begins
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Basic Senses are Developing, Myelin Begins Coating Nerves
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Kidneys are Fully Developed
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Gender Can be Concretely Identified, Sleep Patterns Are Established
Gender is usually determined by ultrasound or something like it. -
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Month Six
Size at the end of this month should be from 11-14 inches and 1.75 to 2 pounds. -
Eyes Can Sometimes Open, Skin is Coated in Vernix
The fetus can hiccup. -
Second Trimester Ends
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Period: to
Month Seven
Size at the end of this month should be from 14 to 16 inches long and 2.5 to 3.5 pounds. -
Taste Buds Have Developed
Fat continues to be stored. Organs are maturing. -
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Month Eight
Size at the end of this month should be from 16.5 to 18 inches long and 4 to 6 pounds. Growth this month will be crazy. -
Brain Growth
Most organs are completed, except for the lungs. Movements can be viewed from the outside. -
Premature Status
If the baby is born at this time, it will be considered premature. -
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First Stage of Labor
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Month Nine
Size at the end of this month should be 19 to 20 inches long, at 7 to 7.5 pounds. -
Lungs Complete Development
The baby settles into head-down position, with slightly less activity. -
Due Date
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Second and Third Stages of Labor
The second stage is delivery of the baby, and the third is delivery of the placenta. -
Period: to
Newborn Status
After this time, the baby is considered an infant.
