Stages of Pregnancy

Pregnancy lasts about 40 weeks, counting from the first day of your last normal period. The weeks are grouped into three trimesters

 

First trimester (week 1-week 12)

The 1st 2 weeks are the 2 weeks before conception and include the woman’s last period. Fertilization occurs in the 3rd week and implantation occurs in the 4th. In the 5th week, the embryo starts to form. In the 6th week, the embryo will be developing basic facial features and its arms and legs start to grow.

 

During the first trimester, the body also undergoes hormonal changes and one may experience symptoms like lethargy, tender and swollen breasts, morning sickness, nausea, mood swings, constipation, frequent urination, headache, heartburn and weight changes

 

Second trimester (week 13-week 28)

Weeks 13 to 28 of the pregnancy are called the second trimester. Most women feel more energized in this period, and begin to put on weight as the symptoms of morning sickness subside and eventually fade away. The uterus can expand up to 20 times its normal size during pregnancy.

 

Although the fetus begins to move and takes a recognizable human shape during the first trimester, it is not until the second trimester that movement of the fetus, often referred to as “quickening”, can be felt. This typically happens in the fourth month, more specifically in the 20th to 21st week, or by the 19th week if the woman has been pregnant before.

 

Third trimester (week 29-week 40)

Final weight gain takes place, which is the most weight gain throughout the pregnancy. The fetus will be growing the most rapidly during this stage, gaining up to 28 g per day. The fetus begins to move regularly, and is felt by the woman. Fetal movement can become quite strong and be disruptive to the woman

 

During this time, the fetal head also descends into the pelvic cavity. As you near your due date, your cervix becomes thinner and softer. This is a normal, natural process that helps the birth canal (vagina) to open during the birthing process. Your doctor will check your progress with a vaginal exam as you near your due date

 

Some body changes you might notice in the third trimester include shortness of breath, heartburn, swelling of the extremities, tender breasts, sticking out of the belly button, trouble sleeping and contractions.

 

References:

http://en.wikipedia.org/wiki/Pregnancy

http://womenshealth.gov/pregnancy

– Kian Hong (Pre and post natal course)