The baby begins as tiny clusters of cells. Your ovaries release an egg into your fallopian tube, where it awaits for the sperm through your cervix and uterus. 75 to 900 million sperm will try to reach that one good egg of yours. Did you know less than a thousand actually make it past your cervix? The baby starts out as a zygote, it has exactly 46 chromosomes (23 pairs). These chromosomes help choose if your baby is a boy or a girl, and what color their eyes and hair color is. The father of the baby determines the sex of the baby. Your little zygote has went through fertilization and is now an embryo embedded through the fallopian tube and will continue its life on your uterus wall. During week 4 of the embryos life it shall split into two parts. One part will become the placenta so the baby can eat and breathe. The other half will continue to grow and one of the biggest part will be created, the babies brain, spinal cord and backbone. From week 6 until birth your baby’s heart will beat about 150 times a minute, twice the average adult rate. At week 25 your baby’s first bowel movement will be forming in the large intestine. The poop is called meconium. Babies normally pass this before they are born, which means it …show more content…
The decrease in multiple births are because the advances in technology with fertility assistance. Twins are two offspring produced by the same pregnancy. 90% of all multiple births are made up of twins. They can either be identical or fraternal. Identical twins means that they are developed from one zygote that splits and forms two embryos. Fraternal twins means that they develop from two eggs which are fertilized by different sperm cells. Did you know twins can have different fathers? One study shows that as many as 1 in 400 sets of fraternal twins are “bipaternal.” It’s possible for one twin to be made during one intercourse and the other twin was conceived during another