Twins (embryology)

embryology guide

1. Topic of presentation TWIN PREGNANCY

2. PREGNANCY: The period from conception to birth is known as pregnancy. OCCURANCE: it occurs when an egg is fertilized by a sperm and then implanted in the lining of uterus Where it develops into placenta At first it is known as embryo after that it is called as Fetus

3. TWIN PREGNANCY: twin pregnancy means a women is carrying two fetus at a same time TYPES: there are two types of twins Monozygotic ( identical twins) Dizygotic (fraternal twins)

4. MONOZYGOTIC TWINS : Monozygotic means “one zygote .” MZ twins develop when one egg is fertilized by one sperm to produce a single zygote. The zygote starts to develop into an embryo but at some time during the first two weeks the developing embryo splits into two identical parts . Each part develops into a baby .

5. TYPES OF MONOZYGOTIC TWINS : Due to the arrangement of placenta and membranes it is divided into 4 types These type depends on division of zygote MONOZYGOTIC twins have same placenta

6. DIZYGOTIC TWINS : These are always DICHORIONIC and DIAMNIOTIC Dizygotic means “two zygotes .” Two eggs are fertilized by two different sperms Forms 2 zygote These zygotes are implanted into uterus seperately