Options Magazine » Pregnancy Information Articles

Your Pregnancy Calendar

It is amazing to watch on film how fast the little cells start to divide when a sperm fertilizes an egg. It is like watching a miracle in progress.

Knowing what is actually going on inside your growing belly is probably the most exciting part of pregnancy. Below you will learn how your baby develops during its nine months inside you.

As soon as a sperm fertilizes the egg that your body sent down one of your fallopian tubes, cellular development begins. This new cluster of cells, smaller than a grain of salt, is called an embryo and has inherited 46 chromosomes—half from you and half from the birth father.

The first thing the embryo does is claim a space on your uterus wall, where it embeds itself between days five and nine. As soon as it has attached itself, it starts letting your hormones know so that your body does not have another period and kick it out. It generates some chemicals and hormones that stop your next period, which is why skipping a period is such a topic of concern. After 17 days, the embryo develops blood cells, and within 19 days it has eyes. Some of the first things to develop are the brain and spinal cord, which make up the nervous system. Your baby has the ability to feel and experience different sensations within its first three weeks. Within 21 to 25 days, a miniature heart is beating.

After just a month of existence, your embryo has a head with ears and an odd-shaped trunk with little buds that will blossom into arms and legs. The embryo measures about a half-inch long and weighs less than an ounce. A placenta surrounds it, filled with a special amniotic fluid that nourishes the embryo. The placenta does not let the mother’s blood in, because your baby has its own blood now. But it does let food and oxygen in from your body.

About the time you miss your second period, the embryo has a complete skeleton with reflexes and brain waves. A little liver has developed that removes impurities from the blood, and the brain controls muscle movement.

At eight weeks, your embryo is officially a fetus (Latin for “offspring” or “young one”). The fetus has a heart, stomach, liver, and brain and most of the other important systems we take for granted every day. It has ears, ankles, wrists, fingers and toes. The eyelids are sealed shut to protect its highly sensitive eyes. Your fetus is only one inch long and weighs little more than an ounce. At ten weeks, you will most likely know for sure that you are pregnant. At ten weeks the baby can squint, swallow, and stick out their tongue. They even have a full set of fingerprints.

By the time the baby is three months old, it will be kicking and thrashing, sucking its thumb, and exercising its lungs by inhaling and exhaling. Soft little nails cover the fingertips and toes, and 20 beautiful buds appear that will later become teeth. At this point the baby has hair and kidneys, as well as a bladder to urinate with. The baby sleeps, wakes, and exercises. At four inches long, the detail is beautifully similar to a fully developed body.

At four months, the baby has developed the organs that make it a male or female, and you can feel him or her kick. The baby has grown to six inches now, weighs about five ounces, and can pass urine. In fact, the baby circulates about 300 quarts of amniotic fluid a day.

At five months, the baby is growing fast. The vocal cords work, and the baby reacts to loud sounds. It also weighs almost a pound, and is eight to twelve inches long.

At six months, or about 26 weeks, the baby is viable, meaning that it might be able to live outside the womb with the help of emergency neonatal care.

At seven months, the baby measures fifteen inches long, weighs about three pounds, and can recognize your voice.
At eight months, the baby is too big to move around much, but hits and kicks up a storm. The little body is building up antibodies to protect it from sickness outside the womb. At eighteen inches long, it now weighs about five pounds. At nine months, the baby is “full term” and ready to be born. The baby weighs between six and nine pounds, and his or her heart pumps 300 gallons of blood per day. The head bones are soft and flexible to make birth easier. That is why most babies have that “conehead” look when they are first born.

Normal pregnancies last nine months and are divided into three time periods called trimesters. During each trimester your body will go through a set of changes brought on by your pregnancy.

During your first trimester, your breasts will grow and may feel sore. You will urinate often because your uterus is growing and putting pressure on your bladder. You may feel more tired than usual. And some women experience nausea referred to as “morning sickness.”

During your second trimester, your abdomen really starts to grow. Morning sickness subsides, and you do not feel as tired or have to urinate as often. You may get leg cramps—a good sign you need more calcium, and you could have heartburn or backaches. Your breasts may begin to produce colostrum, which is intended to nourish the baby before your milk comes in. From this point on, you’ll gain three to four pounds a month until your baby is born.

The third trimester is always the longest stretch of pregnancy. Your feet and ankles may swell from water retention. Urination and leg cramps may occur more frequently. You could be a little more grumpy and tired. When you get really close to birth, your baby will turn inside you and drop lower in your abdomen. This can be uncomfortable, especially with the 25 to 35 pounds you gained since your pregnancy began.

In the end, most women feel that it was all worth it. Pregnancy comes and goes, and the changes that happen to your body will soon be just a memory. Remember to take good care of yourself so your baby is born healthy.