Pregnancy knowledge?

What to expect during pregnancy

Early signs
Stages
Pregnancy healthcare
Complications
Tips
Delivery
Summary

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Pregnancy, or gestation, is a period of around 9 months when an unborn baby is developing in the uterus. The first sign of pregnancy is usually missed menstruation, but there are also others.

Most pregnancies last for about 280 days, which is somewhere around 40 weeks. A pregnancy calculator can help predict when a baby is likely to be born.

This article discusses what to expect for the duration of pregnancy from conception to delivery, including the common symptoms, potential complications, as well as tests and medical exams.
Stefania Pelfini, La Waziya Photography/Getty Images
Recognizing early signs

One of the most common early signs of pregnancy is a missed menstrual cycle. According to the American Pregnancy Association, 29% of pregnant women have reported this as their first sign of being pregnant.

Other than a missed period, signs of pregnancy that may occur from the first few weeks of conception include:

nausea, with or without vomiting
tiredness
dizziness
breast changes such as tenderness
frequent urination due to hormonal changes and increased blood flow through the kidneys
light implantation bleeding or spotting
fatigue

Not all pregnant people experience the same symptoms and some experience no symptoms at all.
Confirming a pregnancy

To confirm a pregnancy, a person can:

see a doctor for a physical exam and a blood pregnancy test
take a home pregnancy test

A pregnancy test detects the human chorionic gonadotropin (HCG) hormone in the blood or urine. HCG is present just a few days after becoming pregnant.

Levels of the hormone are low at the beginning of pregnancy and they gradually increase. Having a high level of HCG can signal a multiple pregnancy, such as when a person is pregnant with twins or triplets.

If a pregnancy test is positive, a person can get an abdominal or transvaginal ultrasound scan.

The scan can confirm:

the gestational age of the pregnancy
how many embryos there are
whether the placement is correct in the womb

Home pregnancy testing kits are available for purchase online.
Pregnancy stages

Doctors measure the fetal age of the baby from the date of conception. But they may determine a pregnant person | s due date by looking at the gestational age, which they measure by counting the pregnancy from the first day of the person | s last menstruation. This includes the period of ovulation and conception.

The following guide follows the gestational age measurement of pregnancy. For more detailed information, see our more thorough series on what to expect during pregnancy week by week.
Weeks 1-13

The first trimester runs through the first 13 weeks, including the period of ovulation and conception.
Conception and implantation

Conception occurs when sperm from a male penetrates an egg from a female and fertilizes it. This usually happens in the female | s fallopian tube after ovulation. The result is a zygote — a unified sperm and egg cell.

Afterward, the zygote immediately starts to divide, forming a cluster of cells called an embryo.

After dividing and growing, the embryo attaches to the wall of the uterus and puts out root-like veins called villi. This process is called implantation.

Occasionally, the embryo implants somewhere other than the lining of the uterus, usually in the fallopian tube. This results in an ectopic pregnancy.

When the embryo implants normally, the villi ensure that the embryo is anchored to the lining of the uterus. They will eventually become the placenta, which feeds and protects the embryo as it develops, supplying it with oxygen and nutrition, and expelling waste.
Early development

The embryo then begins to develop quickly. The first things to develop are the heart, spinal cord, brain, and gastrointestinal tract. The placenta begins to form. As time goes on, more structures and organs grow. By week 6, a doctor may be able to detect a heartbeat.

By week 7, most essential organs are already forming. By week 8, everything that adult humans have both inside and out is present in the embryo in a much smaller form.

By week 9, the embryo becomes a fetus and continues to develop inside the uterus, surrounded by amniotic fluid. This is the “water” that “breaks” just before delivery. By the end of this stage, the fetus will grow to about 3 inches (in) in length and a weight of about 1 ounce (oz).
Symptoms to expect

In the first 13 weeks, the symptoms of pregnancy will likely be similar to those that may occur at the earliest stages, but they may increase as time goes on.

Additional symptoms a pregnant person may encounter at this time includeTrusted Source mood swings, changes in appetite or cravings for certain foods, constipation, headaches, and heartburn.

While some pregnant people may gain weight at this stage, others may lose weight. Not all people experience these symptoms, as every pregnancy is different.
Weeks 13-28

In the second trimester, the fetus forms a type of fine hair called lanugo on its head. It also begins to suck and forms fingerprints.

The sweat glands, eyebrows, eyelashes, and eyes begin to form. The brain, the nervous system, and other essential organs continue to develop.

By week 22, if a fetus is born, it may be able to survive with medical intervention. By week 28, the fetus will grow to about 2 ¼ pounds (lbs) in weight and a length of 14 in.
Symptoms to expect

In the second trimester, pregnant people will usually begin to gain weight. They may begin to feel the movements of the fetus, and others can often feel them by placing a hand on the pregnant person | s abdomen.

Many pregnant people feelTrusted Source more comfortable in the second trimester. Nausea usually stops, and energy levels are often higher. Some people may still experience some discomfort. This may include back pain, carpal tunnel syndrome, itching on the palms of hands or soles of feet, and swelling of the face, fingers, or ankles.

If the swelling is sudden or severe, or if the itching goes along with vomiting, nausea, jaundice, fatigue, or loss of appetite, a person should check with a doctor. These may be signs of preeclampsia or a problem with the liver.

Some people may also notice some discoloration of the skin and may begin to see stretch marks.
Weeks 29-40

The third trimester lasts from week 29 until birth, which is commonly week 40. In the first few weeks of this period, the fetus will really grow in size. It will begin to make some rhythmic breathing movements with its lungs, although these are still developing.

The bones develop fully by this time, but they are still soft. The eyelids will open. After week 33, the fetus will usually make its way into a head-down position in preparation for birth. It will continue to gain more weight and lose its lanugo hair.

From 38 weeks the fetus is considered full-term. It may weigh anywhere from 6 ¾ to 10 lbs with a length of about 16-19 in.
Symptoms to expect

Many of the same symptoms from previous weeks may continue during this time. A pregnant person may experience increased back pain and find it more difficult to rest comfortably. They may urinate more often, due to the pressure on the bladder. In addition, indigestion can result when the fetus pushes against the stomach.

Additional symptoms may include things like hemorrhoids, shortness of breath as the baby presses on the diaphragm, and insomnia.

Some people may find that their breasts are leaking colostrum, a pre-milk substance that the body produces in preparation for milk production.

Early contractions may also occur days or weeks before birth. Doctors call these Braxton–Hicks contractions. They do not indicate labor.