Pregnancy Signs & Symptoms, Week by Week Pregnancy Guide

Pregnancy and birth is an exciting as well as frustrating experience for all women.

Pregnancy refers to the developmental changes in the baby at each stage from conception to childbirth whereas birth refers to the emergence of offspring from the body of the mother.

In general, a pregnancy occurs when a single female sex cell (ovum) fertilizes with a male sex cell (sperm). The chromosomes of these cells combine to form a new single cell.

Once the fertilization takes place, the fertilized egg called zygote will move down after three days. The fertilized egg will begin to move down from the fallopian tube to uterus within 3-5 days after fertilization.

Thus, the fertilized egg enters the uterus and starts dividing the cells, which is called a morula.

The morula then becomes blastocysts and implants itself in the uterus lining within ten days after conception. Now, the fertilized egg enters the embryonic stage and is called embryo.

The embryo is protected by amniotic fluid. The placenta, a fleshy organ develops and attaches the embryo to the uterus through an umbilical cord.

Thus, placenta and umbilical cord helps transfer oxygen and essential nutrients to the embryo in the uterus through blood circulation. It also helps excrete waste products from the embryo into the bloodstream.

In the embryonic stage of pregnancy and birth, most of the internal organs and external body structures will form. Thus, it gets an identifiable human shape. This formation generally starts about three weeks after conception.

The brain and spinal cord will start developing by day 14or 15. The formation of heart and blood vessels will begin within 16-17 days of conception.

The heart starts pumping fluids via blood vessels by day 20, and the formation of red blood cells starts by day 21.

By eight weeks after fertilization, majority of organs will form completely except brain and spinal cord because they continue to grow all through the pregnancy. Remember that eight weeks after fertilization is equal to ten weeks of pregnancy.

In this stage of pregnancy and birth, the embryo is highly susceptible to the affects of medications, diseases, and radiations. Therefore, a special care is required during this stage. Live-virus vaccinations and related drugs should be avoided until it is essential for you.

The embryo, after eight weeks of fertilization, is treated as fetus. During this stage of pregnancy and birth, already formed body structures will grow and develop. The fetus occupies the entire uterus by about twelve weeks of pregnancy.

The sex of the baby appears when you are 14 weeks pregnant and the movements will be known within 16-20 weeks.

When you are 23 weeks pregnant, the blood vessels of the lungs start developing and it continues to grow throughout pregnancy. Also, the fetus has chance for survival outside the uterus.

When you are 33 weeks pregnant, almost all other organs develop fully. The amniotic fluid increases and the growth of brain will increase. By 36-40weeks, the fetus becomes almost ready and can drop into the birth canal and is about to deliver.

So, taking proper care during pregnancy and birth can result in a strong and healthy baby.