Fetal Models for Understanding Pregnancy

Pregnancy is a roughly 40-week process, beginning with an oocyte’s fertilization and ending with delivery of the baby. Every year in the United States, just under four million babies are born, and understanding the phases of pregnancy can be a boon to both parents and help them understand the complicated, delicate development of a fetus. Fetal models allow doctors and other experts to illustrate the phases of pregnancy to prospective parents, and a pelvis model can show how a woman’s reproductive organs work. A stages of labor video, a fetal progress chart, prenatal development chart, and more can make pregnancy understandable.

Nine months is the common standard for the length of human pregnancy, but in fact, there is a five month variation around 40 weeks, and usually, only about 4% of women will deliver their child right on their 40 week due date. Various hormones can help the process along; adrenaline, the fight or flight hormone, plays a part in delivery, and it gives a woman a rush of energy to stimulate contractions, although an excess can actually impede labor, something doctors can look out for. Fetal models and other charts, meanwhile, will illustrate pregnancy to future parents, along with the phases of fetal development along the way.

The Stages of Pregnancy

According to Cleveland Clinic, once a sperm cell has penetrated a woman’s egg cell, the egg’s protein coating changes to block further sperm from entering. Even at this initial phase, the baby’s genetic makeup is set, and the presence of an X or Y chromosome will determine if the child is a boy or girl. The egg cell, now a blastocyte, begins reproducing itself and passes through the Fallopian tube and into the uterus, where it will attach to the endometrium. Within three weeks, the blastocyte becomes an embryo, and its first nerve cells have already developed. From there, the three trimesters of pregnancy begin, and each month of the whole pregnancy has different developments for the fetus. Fetal models can show how each stage works.

The first trimester is roughly the first three months of pregnancy. During the first trimester’s first month, the amniotic sac, a water tight sac, forms around the embryo to cushion it, and the prototype eyes, throat, and lower jaw start to form. The embryo is only one quarter of an inch long. During the second month, the beginnings of the arms and legs form, along with fingers and toes, and after the 8th week, the embryo is considered a fetus. Finally, during the third month of this trimester, the arms and legs, as well as hands and feet, fully form, and the fetus can even open and close its hands, and at the end of this month, the baby is about one inch long. Fetal models can show how small and oddly proportioned the embryo or fetus is during this trimester, with the developing limbs and large head compared to the body.

The fetus grows much larger during the second trimester, which is roughly the next three months of pregnancy, and fetal models can show just how more advanced the fetus has become. Throughout this trimester, the fingernails, eyelids, teeth, and bones develop and harden, and by now, a heartbeat can easily be detected, and the sex of the fetus can be determined. It will start to move, and hair may grow on its head. By the end of this trimester, the baby may survive in intensive care if it is born on or after the 23rd week, and it will be 12 inches long.

The third and final trimester is when the baby becomes even more likely to survive being born, and its senses rapidly develop to outside stimuli. The fetus will now start responding to light, touch, and sound, and will move position frequently. The fetus starts developing body fat, and it can start to see and hear properly, and its brain is rapidly developing. By the ninth month, the baby takes up nearly all the room in the uterus, and it will shift head-down, preparing to be born head-first. By now, the baby is 18 to 20 inches long and may weigh around 7 pounds or more, and it is ready to move through the birth canal and be delivered.

Leave a Reply