Difference Between Embryo, Fetus, and Baby in Pregnancy Phase


From conception to birth, there are stages called baby development phases. At this moment, there are physical changes that occur in the mother’s stomach, starting from fertilization to produce a zygote, developing into an embryo, fetus, and finally a baby.

Apart from the shape, there are other things that underlie the differences between embryos, fetuses, and babies . Come on, know the meaning and differences of these three stages of human fetal development .

What is an embryo?

James O’Brien, MD., a medical director of inpatient obstetrics at Women & Infants Rhode Island Hospital told The Bump that an embryo is a pregnancy that develops from fertilization to 8 weeks.

The process of becoming an embryo begins when a sperm cell enters an egg cell or a mature oocyte . When the two meet, the DNA from these two cells fuses, forming a zygote.

This new form, then divides repeatedly into smaller embryonic cells.

About 4 days after fertilization, the morula which is near in the uterine cavity develops a sac of fluid called a blastocele. The blastocele is surrounded by cells. At this time the embryo reaches the blastocyst stage.

The above process takes place about 6 days after fertilization. Next, the blastocyst attaches to the endometrium or uterine lining and takes its nutrients.

Due to attachment, the embryo receives nutrients from the blood supply of the pregnant person. Through the placenta, it serves to carry nutrients and oxygen to the embryo or fetus as well as carry waste and carbon dioxide.

The placenta also makes hormones that maintain pregnancy. In addition, it affects changes in the body and provides what the fetus needs to grow.

At the time of becoming an embryo, there is a process of development in the central nervous system, heart tissue, fingers, lungs, inner ear, muscles, mouth, nose, and eyes. Although still vague, the whole process occurs from the first to the 8th week of pregnancy.

What is a fetus?

After passing the 8th week of pregnancy, the embryo turns into a fetus. This title is given to prospective babies who enter the age of the 9th week.

The term fetus is valid until the baby is born. At this time, the fetal body develops and continues to grow to form other organs. Starting from the eyelids, fingernails, liver, and gender. Until finally there is an increase in fat, as well as organs and systems that function fully.

There is no exact time to describe the viability of the fetus surviving outside the womb. However, a fetus that is at least 24 weeks old, can live with intensive care after birth.

Babies born before 30 weeks of gestation are less likely to survive than older babies. The reason is that important organs, such as the lungs and brain, have not yet formed maturely.

What is baby?

After reaching the end of pregnancy, the mother will experience a period of birth. Well, the transition between the fetus inside birth to the outside world is called a baby.

To prepare for life outside the womb, the fetus will produce hormones (such as cortisol, adrenaline, and thyroid hormone) which will surge at birth. That way, it allows the newborn to maintain normal blood sugar levels, body temperature, and blood pressure with ease.

If while in the womb the fetus relies on the umbilical cord to provide adequate nutrition and oxygen, once born everything is done alone. This causes blood flow to the lungs to increase, because the neonate or newborn has to breathe in order to pick up oxygen on its own in the lungs.

Only then does the baby pass through the beginning of life in the outside world. In the first three months, the baby is referred to as newborn to infant. The term baby survives from human birth until it reaches the age of 1 year.

This period is included as the golden age . The stages of infant development from 0-12 months are very important to form a child’s ability.

Difference between embryo, fetus and baby
The terms or designations embryo, fetus, and baby indicate different stages of development. All three do not describe the same condition, although all of them are in the stage of pregnancy until delivery.

When it becomes an embryo, the baby will experience many things that can shape his body system. Reported by Healthline, the embryonic stage can be regarded as the foundation of child development. Meanwhile, the fetus has passed it and is in its growth phase.

Embryos generally have not formed a complete baby body, but are still in the form of a sphere that is almost difficult to see. Unless it has grown some organs in the last stage of the 9th week. Meanwhile, the fetus undergoes a shaped phase as the baby is born.

As for the baby, it is the stage after the embryo and fetus are fully formed, then ready to be born into the world. Furthermore, the baby passes through the first year until later referred to as a toddler or toddler.

The differences between embryos, fetuses, and babies are inherent in the process of growth and development. In addition, the time of occurrence also determines the designation. Although at first glance the same, this term is important to describe conditions in the womb and after birth.