Difference Between Gestation and Pregnancy | Gestation vs Pregnancy

Key Difference – Gestation vs Pregnancy

The human’s reproduction is completely sexual reproduction. This involves the union of the sperms of a male with the ovum of a female. The aforementioned process is known as fertilization, and it produces a zygote which is diploid. The zygote divides by mitosis and results in an embryo which develops into the fetus. The fetus is grown and developed in the uterus. Gestation is the time period between conception (or fertilization) and birth. The baby grows and develops fully in this period in mother’s womb. The meaning of gestation is carrying the embryo or fetus in the female’s womb in mammalian or nonmammalian species. On the other hand, pregnancy is the process which includes series of changes occurs in woman’s body and tissues due to the reason for carrying or developing a fetus. The key difference between gestation and pregnancy is, gestation is the period of carrying the fetus in the woman’s womb while the pregnancy is the series of changes that take place in woman’s body and tissues due to the developing fetus in the female’s womb.


1. Overview and Key Difference
2. What is Gestation
3. What is Pregnancy
4. Similarities Between Gestation and Pregnancy
5. Side by Side Comparison – Gestation vs Pregnancy in Tabular Form
6. Summary

What is Gestation?

The gestational age is determined as the time period since the first day of the last menstrual period to birth. Normally the conception occurs after two weeks of the last menstrual period. The time period in the gestation is called as gestational period and usually, this period is 266 days or 40 weeks or 9 months. During this period, the fetus grows and develops fully in the mother’s womb.

The fetal development occurs in three phases during the gestation period. They are an ovular period, embryonic period and the fetal period up to delivery. The ovular period and embryonic period last for 10 weeks. The ovulation takes place between 11-21 days from the first day of the last period. If the conception is successful, the sperm penetrates the egg and forms the unit that is consisted of a single set of 46 chromosomes called “zygote.” This unit is the basis for a new human being. The fertilized egg is spending a couple of days while traveling from fallopian tube towards the uterus. The fertilized egg is dividing and first converts to morula stage (an early embryonic period with blastomeres cells) and further dividing is resulting in the blastocyst. The blastocyst contains the inner cell mass (ICM) which later develops into the embryo. Anywhere, during 6-12 days after conception, the blastocyst embeds in uterus lining and starts developing into an embryo. The embryonic development occurs as follows,

  • 3rd week- Development of brain, heart, gastrointestinal tract.
  • 4-5 weeks- Arms and legs are visible.
  • 6th week- Lung, jaws, nose, and palate formation.
  • 7th weeks- Every essential organ is forming. Hair and nipple follicles are forming. Eyelids and tongue start forming.
  • 8th week- External ears are forming. Every part of the adult body is visible now in the tiny body.
  • 10th week- The last stage of the embryogenic period.