Fertilization: What is it? Development of an Embryo, Chromosomes, Blastocyst and Artificial Fertilization

It usually occurs during the two weeks after the first day of the last menstrual period.

The pregnancy week that you enter has a date from the first day of your last period. This means that in the first two weeks or so, you are not really pregnant, your body will prepare for ovulation in a normal way.

It provides a summary of each stage of pregnancy, and you have to wait for knowledge about how your baby is developing.

Development of an embryo

The fertilized egg (zygote) divides repeatedly as it descends through the fallopian tube into the uterus. First, the zygote becomes a solid ball of cells. Then it becomes a hollow ball of cells called a blastocyst.

For fertilization to occur, the sperm must be ejaculated in the vagina through sexual intercourse or otherwise inserted through the opening of the cervix to travel to the fallopian tubes.

Once in the fallopian tubes, the sperm will penetrate and fertilize the egg. During the third week after the first day of your last period, your fertilized egg moves along the fallopian tube to your womb.

Once united, the egg and sperm form a zygote that contains 46 chromosomes, 23 of the female and 23 of the male, which will ultimately determine the genetic makeup of your child.

What are chromosomes?

These chromosomes will determine the sex and physical characteristics of the fetus, and will influence personality and intelligence.

Chromosomes are small threadlike structures that each carry around 2,000 genes. Genes determine inherited characteristics of a baby, such as hair and eye color, blood type, height and build.

A fertilized egg contains a sexual chromosome of its mother and one of its father. The sexual chromosome of the ovule is always the same and is known as the X chromosome, but the sexual chromosome of the sperm can be an X or Y chromosome.

If the ovum is fertilized by a sperm that contains an X chromosome, the fetus will be a female (XX). If the sperm contains a Y chromosome, the fetus will be male (XY).

The trip of the zygote has just begun, it will spend several days going down the fallopian tube, at that time it will become a morula, a ball of 12 to 15 cells and then a blastocyst.

The blastocyst:

At this point it is multiplying rapidly, it is a grouping of cells that contains an internal collection of cells. This blastocyst will eventually become the embryo and an outer layer whose purpose is to provide protection and nourishment to the growing embryo.

At this point, your future baby is still a group of cells measuring approximately .0019 inches, which is about the size of a pinhead.

During this time, it is important to talk with your health care provider about your current or desired exercise routine and your nutritional status. It can be recommended to increase your intake of folic acid and other vitamins.

Substances that can harm your growing baby and should be avoided include alcohol, illegal drugs, certain medications and foods. Caffeine and smoking should be discussed with your health care provider.

At this stage of pregnancy, there are very few expected symptoms, however, some women may have mild cramping and an increase in vaginal discharge during the ovulatory stage.

Recent developments on fertilization

The technique of selective embryos could improve in vitro fertilization. In a new study published in the journal Biomicrofluidics, researchers from Taiwan reveal the creation of a new technique that they believe could lead to more effective and cheaper in vitro fertilization for couples who have difficulty conceiving.

IVF: The benefits and risks

Recently, members of the UK parliament voted in favor of the legalization of mitochondrial donation, a form of IVF that could prevent the transmission of serious genetic diseases from mother to offspring.

IVF embryos:

The complete genetic code can be scanned for mutations Genetic scientists have used a new technique that allows the whole genome of FIV embryos to be scanned by cells from 10 biopsies.

The researchers say the tests are the first to detect all new genetic mutations that happen uniquely in an individual, compared to those that have been transmitted by parents.