Gestation vs Pregnancy
What is gestation and pregnancy?
In humans, the process of reproduction is sexual. It involves the union of the sperm produced by the male and the ovum produced by the female. This process is called fertilization. It results in the formation of the zygote, which undergoes divisions to develop into the embryo. The embryo then develops into the foetus. The growth and development of the foetus takes place in the uterus.
Gestation is the period of time between conception/fertilization and birth. During this time, the baby grows and develops inside the mother’s womb. Gestation means carrying, to carry or to bear. Gestation is the carrying of an embryo or foetus inside the female’s womb in mammals and non-mammalian species. Pregnancy, more accurately, is the process and series of changes that take place in a woman’s body and tissues as a result of the developing foetus. During a pregnancy, there can be one or more gestations occurring simultaneously; for example in case of twins.
Difference in duration
The gestational age is counted as the time since the first day of the last menstrual period. Conception occurs two weeks after the last menstrual period. The time period of gestation is called the gestational period. The gestational period is 266 days or 40 weeks or 9 months.
Pregnancy is divided into three trimesters, each three months long. First trimester starts from the last period to the 13th week. Second trimester starts from the 14th to 27th week. Third trimester starts from 28th to 40th week. Normal pregnancy occurs at the gestational age of 38-42 weeks. Infants born before 37 weeks are called premature. Birth taking place after 42 weeks is post mature delivery.
Difference in the process
During the gestational period, the fetal development occurs in three phases. Firstly, the ovular period, followed by the embryonic period which lasts up to the 10th week and lastly, is the fetal period upto delivery. At 5 weeks, the cells of the embryo specialise into the nervous system, organs, skin etc. The embryo is made up of 3 layers- the outer ectoderm, the middle layer called mesoderm and the inner layer called endoderm.
During pregnancy, the female gains weight and develops symptoms like nausea, vomiting, tiredness, increased frequency of urination and tenderness in the breast. Other symptoms include constipation, heartburn, piles, varicose veins, leg cramps and backache. Stretch marks appear on the thighs, abdomen, buttocks and breast. There are other subtle signs that announce a pregnancy as well, like the vagina becomes deep blue in colour, etc.
Pregnancy is diagnosed by the urine pregnancy test. Increased levels of the hormone human chorionic gonadotrophin (hCG) in the blood and urine are diagnostic. Ultrasonography is useful in determing the fetal age and confirming the pregnancy.
Summary:
Gestation is the time period between conception and birth during which the embryo or foetus is developing inside the uterus. Gestation means to carry. Gestational age is calculated from the first day of the last menstrual cycle. Gestational period in a human female normally is 266 days. Pregnancy is the series of changes that take place in a woman’s body tissues as a result of the developing foetus. Pregnancy is divided into three trimesters each lasting for 3 months.