Your Guide to the First Trimester of Pregnancy

Pregnancy lasts for 40 weeks and the entire span is broken into trimesters. The first trimester includes the moment of conception and goes up to week 12. This is an exciting time, but it is also a time filled with questions.

Especially for first-time mothers, the first trimester of pregnancy is a time of great uncertainty and a period filled with expectations and hopes. The first trimester of pregnancy includes the moment of surprise to find that you are pregnant followed by the quite serious reality of how to carry the pregnancy to term.

What exactly is the first trimester of pregnancy? What symptoms should you be aware of? What happens to your baby during the first trimester of pregnancy? What should you do during the first trimester of pregnancy to take care of your health and the health of your baby? This guide will give you the information you need to understand your first trimester of pregnancy.

What is the first trimester?

The first trimester of pregnancy is the first 12 weeks. The first trimester includes the moment of conception up through the 12th week in which the earliest changes for the baby and to a woman’s body happen quickly.

A woman’s body goes through many changes during the first trimester, and these changes often raise many serious questions. The areas of most concern during the first trimester include:

Pregnancy diet
What kind of prenatal testing and prenatal vitamins are necessary
What is a healthy amount of weight gain?
What steps should you take to ensure the health of your developing baby?

Since the changes that occur in the first trimester can be dramatic, it can be a time of uncertainty for many women. A woman’s body begins to change in order to accommodate the development of a baby and these changes produce some pronounced symptoms.

First trimester symptoms

Much of what happens during the first trimester of pregnancy is invisible, but the changes that occur can produce some dramatic symptoms. A woman's body goes through some major changes. Some of these changes affect a woman's body and her emotional state. Knowing what is going on takes the mystery out of things and helps you understand what is happening.

The first trimester can produce physical symptoms:

Tender and swollen breasts

Hormone changes can make your breasts feel sore and tender. This discomfort usually lessens after a few weeks after your body adjusts to the hormone changes.

Nausea with or without vomiting

This is the so-called morning sickness that many women experience. Nausea can begin within the first month and it is generally due to the hormone changes that come with pregnancy. Avoid having an empty stomach during this time. Eat foods that are low in fat. Also, ginger has been known to help alleviate morning sickness.

Frequent urination

You may experience an increase in urination. This is due to the increased blood in your body to accommodate the baby, and this causes your liver and kidneys to process extra water.

Fatigue

In the first trimester, there is a surge of the hormone progesterone which can put you to sleep. It is important to rest as much as you need to during this time.

Food cravings and aversions

The hormone changes during the first trimester can cause you to crave certain foods. These hormone surges may also produce some serious food aversions.

Heartburn

The hormones that come with pregnancy can relax the valve between your stomach and esophagus. This causes heartburn for many women. Eat small meals and avoid fried foods, acidic citrus fruits, and spicy foods.

Constipation

The increased levels of the hormone progesterone can slow down the movement of food through your digestive system. This leads to constipation for some women. If you are taking iron supplements, this can exacerbate the problem. Make sure to eat plenty of fiber. Drink plenty of fluids. Prune juice and other fruit juices can also help.

Your emotions can go through some tumbles during the first trimester of pregnancy. Some of the emotional symptoms can include the following:

You may experience feelings that run from exhilaration to anxiety. The exhaustion that comes in the first trimester can make these emotional shifts more pronounced.
It is perfectly normal to be concerned about the health of your baby and your own health. This is a huge step in life, and a certain amount of anxiety and worry is to be expected. Mood swings, anxiety, and intense feelings are to be expected with pregnancy and you should not be alarmed by your moods. If you experience mood swings that are severe or unmanageably intense, you should consult your doctor.

Changes during the first trimester

Your body changes fast during the first trimester of pregnancy. A woman's body goes through a rapid transformation to nourish and protect a developing baby. Some of the most notable changes during the first trimester include:

Enlarged mammary glands

The breasts begin to swell and become tender as estrogen and progesterone levels undergo changes to accommodate the developing baby.

Darkened areolas

The area surrounding your nipples will likely darken and enlarge.

Veins

Veins in your breasts will become more pronounced and noticeable.

Uterus growth

The uterus grows to accommodate the growing baby. This can put pressure on your balder causing you to urinate more frequently.

Mood swings

Mood swings that are similar to those experienced during premenstrual syndrome.

Increased hormone levels

Hormone levels increase to sustain the pregnancy. These are also the main cause of nausea and vomiting associated with morning sickness.

Cardiac volume increases

About 40 to 50 percent of the beginning and end of pregnancy. This causes an increase in cardiac function. All of this is due to the increased blood volume necessary for blood flow to the developing fetus.

Baby’s growth during the first trimester

The stages of growth for a baby during the first trimester include:

First four weeks:

All major organ systems are formed.
The neural tube is formed. This will become the brain, spinal cord, the digestive system, heart, and circulatory system.
The beginnings of ears and eyes develop.
Limb buds are formed.
The heart starts beating.

Four to eight weeks:

All major organ systems are developing. This includes the circulatory system, nerves, digestive system, and urinary system.
The embryo takes on a human shape.
The mouth begins to develop complete with tooth buds which will become baby teeth.
The eyes, nose, mouth, and nose become more distinct.
Arms and legs become more fully formed.
Fingers and toes can be discerned.
Bones begin to develop.
The embryo is in constant motion during the stage, although these movements cannot be felt by the mother.

Nine to twelve weeks:

External genital organs develop.
Fingernails and toenails appear.
Eyelids are formed.
Fetal movement increases.
Arms and legs are fully developed.
The larynx (voice box) and trachea are formed.

It is during the first trimester that the embryo is transformed from a group of cells into a fully formed fetus.

First Trimester of Pregnancy To-Do List

The first trimester is an exciting and emotional time

From the moment you discover that you are pregnant to the series of changes that unfold during this time, the first trimester is a period to take stock of some things.

Take time for your feelings

There are many practical things that lay ahead. But first, give yourself time to take some stock of your feelings at this time. This is a life-changing time, and you need to allow yourself some time to think about how you feel.

Stop smoking and drinking alcohol

This may not be the most fun thing to think about, but it is crucial to the health of your developing baby that you stop drinking all alcohol. Alcohol causes serious health problems in a developing fetus. If you smoke, you should stop smoking anyway, but this is a crucial time to stop smoking.

Call your doctor

Schedule an appointment with your OB/GYN. Get the initial information on your pregnancy and your baby. This is a time to discuss ideas about homebirth vs hospital birth, natural childbirth, and general medical care.

Plan a prenatal diet

With the help of your doctor or midwife, start working out a diet that is healthy for you and your baby.

Think about an exercise routine

You do not need to become an exercise fanatic during your first trimester. But you can alleviate some of your symptoms by staying active. Talk to your doctor about the kinds of exercises that will be best for you.

Insurance

Do the research on your health insurance. Find out what is covered and what is not. You do not want financial surprises. Check to see if pre- and post-natal care is covered by your insurance and make arrangements for what is not fully covered.

Start a baby budget

This is the time to begin thinking about the financial realities of having a baby. The first trimester is still early in the process and it is a great time to begin budgeting for your new addition to the family.

Learn how to manage symptoms

The first trimester brings morning sickness and other forms of discomfort. Learn how to manage these things to minimize your own discomfort.

This list could go on and on, but the important things are to look after your health and the health of your developing baby.

First Trimester of Pregnancy FAQs

What is the first trimester of pregnancy?

What symptoms can I expect during the first trimester?

The first trimester can bring nausea and vomiting—the so-called morning sickness. Your breasts may swell and become tender. You may experience mood swings. And you can expect to be more tired.

What changes can I expect during the first trimester?

You will undergo increased hormone levels, breasts will become larger, you may experience nausea and vomiting, and your cardiac volume will increase by as much as 50 percent to accommodate the increased blood flow to your developing baby.

What changes does my baby go through in the first trimester?

The first trimester is the most dramatic period for the growth of the baby. During the first 8 weeks, a fetus grows from an embryo into a fully formed fetus weighing about ½ ounce to 1 ounce and 3 to 4 inches long. During the first trimester, your baby will develop arms, legs, bones, all the major organ systems, and begin to move around.

Conclusion

Pregnancy is a serious and exciting time. The first trimester is perhaps the most exciting time. From going through the first days of knowing you are going to have a baby, to the initial changes your body goes through, the first trimester is an intense time.

The fetus goes through some of the most dramatic development during the first trimester. It is during these phases that an embryo is transformed into a baby. From a cluster of cells to bones, arms and legs, and a full face your baby takes on the first stages of life.

You will go through some intense changes also. Everything from the well-known morning sickness to some fairly dramatic changes in how you look, the first trimester transforms a woman’s body into a mother’s body.

But ultimately, the first trimester is exciting. There are plans to make both practical and fun. Doctor’s appointments and shopping for baby things all become realities during the first trimester. With some knowledge of what is coming and with a little planning, you can make the most of your first trimester of pregnancy and prepare for your second trimester of pregnancy.