What happens in the first month of pregnancy?

Pregnancy is divided into 3 trimesters. Each trimester is a little longer than 13 weeks. The first month marks the beginning of the first trimester.

What’s gestational age?

Pregnancy timing is measured using “gestational age.” Gestational age starts on the first day of your last menstrual period (LMP).

Gestational age can be confusing. Most people think of pregnancy as lasting 9 months. And it’s true that you’re pregnant for about 9 months. But because pregnancy is measured from the first day of your last menstrual period — about 3-4 weeks before you’re actually pregnant — a full-term pregnancy usually totals about 40 weeks from LMP — roughly 10 months.

Many people don’t remember exactly when they started their last menstrual period — that’s OK. The surest way to find out gestational age early in pregnancy is with an ultrasound.

What happens during week 1 – 2?

These are the first 2 weeks of your menstrual cycle. You have your period. About 2 weeks later, the egg that’s most mature is released from your ovary — this is called ovulation. Ovulation may happen earlier or later, depending on the length of your menstrual cycle. The average menstrual cycle is 28 days.

After it’s released, your egg travels down your fallopian tube toward your uterus. If the egg meets up with a sperm, they combine. This is called fertilization. Fertilization is most likely to occur when you have unprotected vaginal sex during the 6 days leading up to — and including the day of — ovulation.

What happens during week 3 – 4?

The fertilized egg moves down your fallopian tube and divides into more and more cells. It reaches your uterus about 3–4 days after fertilization. The dividing cells then form a ball that floats around in the uterus for about 2–3 days.

Pregnancy begins when the ball of cells attaches to the lining of your uterus. This is called implantation. It usually starts about 6 days after fertilization and takes about 3–4 days to be complete.

Pregnancy doesn’t always happen, even if an egg is fertilized by a sperm. Up to half of all fertilized eggs pass out of your body when you get your period, before implantation is complete.

What are the signs of pregnancy?

For a lot of people, the first sign of pregnancy is a missed period. Most pregnancy tests will be positive by the time you’ve missed your period. Other early pregnancy symptoms include feeling tired, feeling bloated, peeing more than usual, mood swings, nausea, and tender or swollen breasts. Not everyone has all of these symptoms, but it’s common to have at least 1 of them.

What happens in the second month of pregnancy?

The ball of cells turns into an embryo at the start of the 6th week. The embryonic stage of pregnancy lasts about 5 weeks. This is when all the major internal organs start developing.

What happens during week 5 – 6?

The embryo is less than 1/5 inch (4–5 mm) long.
A very basic beating heart and circulatory system develop.
Buds for arms and legs develop.
The neural tube begins forming. The neural tube will later form the brain, spinal cord, and major nerves.
The bud of a tail develops.
The umbilical cord begins developing.

What happens during week 7 – 8?

The embryo is 1/4 to 1/2 inch (7–14 mm) long.
The heart has formed.
Webbed fingers and toes develop.
The arms bend at the elbows.
External ears, eyes, eyelids, liver, and upper lip begin forming.
The sex organs are the same — neither female nor male — in all embryos until the 7th or 8th week. If a gene triggers the development of testes, the embryo develops as a biological male. If there isn’t a trigger, the embryo develops ovaries and becomes biologically female.

What are the symptoms of pregnancy in the second month?

Pregnancy symptoms often become very noticeable when you’re 2 months pregnant. Common discomforts like breast tenderness, feeling very tired, peeing more often, heartburn, nausea, and vomiting usually get worse. Your body produces extra blood during pregnancy, and your heart beats faster and harder than usual to carry the extra blood.

What happens in the third month of pregnancy?

The embryo becomes a fetus when you’re 3 months pregnant. The umbilical cord connects the fetus to your placenta and uterine wall. External sex organs also start to develop.

What happens during weeks 9 – 10?

The embryo develops into a fetus after 10 weeks. It’s 1–1.5 inches (21–40 mm) long. The tail disappears. Fingers and toes grow longer. The umbilical cord connects the abdomen of the fetus to the placenta. The placenta is attached to the wall of the uterus and it absorbs nutrients from the bloodstream. The cord carries nutrients and oxygen to the fetus and takes waste away from the fetus.

What happens during weeks 11 – 12?

The fetus is now measured from the top of its head to its buttocks. This is called crown-rump length (CRL).

The fetus has a CRL of 2–3 inches (6–7.5 cm).
Fingers and toes are no longer webbed.
Bones begin hardening.
Skin and fingernails begin to grow.
Changes triggered by hormones begin to make external sex organs appear — female or male. The fetus begins making spontaneous movements.
Kidneys start making urine.
Early sweat glands appear.
Eyelids are fused.

What are the symptoms of pregnancy in the third month?

Many of the pregnancy symptoms from the first 2 months continue — and sometimes worsen — during the third month. This is especially true of nausea. Your breasts continue growing and changing. The area around your nipple — the areola — may grow larger and darker. If you’re prone to acne you may have outbreaks.

You probably won’t gain much weight during the first 3 months of pregnancy — usually about 2 pounds. If you’re overweight or underweight you may experience a different rate of weight gain. Talk with your nurse or doctor about maintaining a healthy weight throughout your pregnancy.

Miscarriage

Most early pregnancy loss — miscarriage — happens in the first trimester. About 15 percent of pregnancies end in miscarriage during the first trimester.

What happens in the fourth month of pregnancy?

Your 2nd trimester begins during your 4th month of pregnancy, starting on week 14.

What happens during weeks 13 – 14?

The fetus has a CRL of about 3 inches (8 cm).
The biological sex of the fetus can sometimes be seen by looking at external sex organs on an ultrasound.
Hair begins to grow.
The prostate gland begins developing in biologically male fetuses.
Ovaries move down from the abdomen to the pelvic area is biologically female fetuses.
The roof of the mouth is formed.

What happens during weeks 15 – 16?

The fetus has a CRL of about 4.5 inches (12 cm).
Hundreds of thousands of eggs form in the ovaries of biologically female fetuses.

What are the symptoms of pregnancy in the fourth month?

Some of the early signs and symptoms of pregnancy go away when you’re 4 months pregnant. Nausea usually lessens. But other digestive problems — like heartburn and constipation — may be troublesome. Breast changes — growth, soreness, and darkening of the areola — usually continue. It’s common to have shortness of breath or to breathe faster. Increased blood flow may lead to unpleasant pregnancy symptoms, such as bleeding gums, nosebleeds, or nasal stuffiness. You also may feel dizzy or faint because of changes in your blood and blood vessels.

What happens in the fifth month of pregnancy?

When you’re 5 months pregnant, your fetus develops soft body hair and a greasy coating that helps protect the skin.

What happens during weeks 17 – 18?

The fetus has a CRL of 5.5–6 inches (14–15 cm).

What happens during week 19 – 20?

The fetus has a CRL of about 6.5 inches (16 cm). Lanugo — a fine downy hair — covers the body. The skin is also covered with vernix caseosa, a greasy material that protects the skin. A uterus forms in a biologically female fetus.

What are the symptoms of pregnancy in the fifth month?

People usually feel fetal movements for the first time during the fifth month. It may feel like flutters or butterflies in your stomach. This is sometimes called quickening.

The pregnancy symptoms of the fourth month continue this month. Heartburn, constipation, breast changes, dizziness, shortness of breath, nose bleeds, and gum bleeding are common. Your breasts may be as much as 2 cup sizes bigger by now.

What happens in the sixth month of pregnancy?

During the 6th month, your fetus starts to develop blood cells, taste buds, eyebrows and eyelashes.

What happens during week 21 – 22?

The fetus has a CRL of about 7 inches (18–19 cm).
Bone marrow starts making blood cells.
Taste buds begin to form.

What happens during week 23 – 24?

The fetus has a CRL of about 8 inches (20 cm).
Eyebrows and eyelashes usually develop between weeks 23 and 26.

What are the symptoms of pregnancy in the sixth month?

Pregnancy symptoms from the fourth and fifth month usually continue. Shortness of breath may improve. Your breasts may start producing colostrum — tiny drops of early milk. This may continue throughout the rest of your pregnancy.

Some women have Braxton-Hicks contractions when they’re 6 months pregnant. They feel like a painless squeezing of the uterus or abdomen. This is the uterus’s way of practicing for labor and delivery. Braxton-Hicks contractions are normal and not a sign of early labor. But check with your doctor if you have painful or frequent contractions or if you have any concerns.

What happens in the seventh month of pregnancy?

Your 3rd trimester starts during your 7th month of pregnancy, on week 28.

What happens during week 25 – 26?

The fetus has a CRL of about 9 inches (23 cm).
The fetus develops more and more fat from now until the end of pregnancy.

What happens during week 27 – 28?

The fetus has a CRL of about 10 inches (25 cm).
Eyelids are usually fused together until about 28 weeks.

What are the symptoms of pregnancy in the seventh month?

Your uterus continues to expand when you’re 7 months pregnant. Back pain is common. Pregnancy symptoms from earlier months continue. Dizziness may lessen.

What happens in the eighth month of pregnancy?

During your 8th month of pregnancy, your fetus is about 11 inches long, and the lanugo (the fine, soft hair that covers your fetus’s body) begins to fall off.

What happens during week 29 – 30?

The fetus has a CRL of about 10.5 inches (27 cm).
Testes usually begin descending into the scrotum from the abdomen between weeks 30 and 34 in a biologically male fetus. This is usually complete by 40 weeks.

What happens during week 31 – 32?

The fetus has a CRL of about 11 inches (28 cm).
Lanugo starts falling off.

What are the symptoms of pregnancy in the eighth month?

You may feel tired and have a more difficult time breathing as your uterus grows upward. You may get varicose veins — blue or red swollen veins most often in the legs — or hemorrhoids — varicose veins of the rectum. Hemorrhoids can be painful and itchy and can cause bleeding. You may also get stretch marks where your skin has expanded. Braxton-Hicks contractions, heartburn, and constipation may continue. You may urinate a bit when sneezing or laughing because of pressure from your uterus on your bladder. Hormones may make your hair appear fuller and healthier.

What happens in the ninth month of pregnancy?

When you’re 9 months pregnant, your fetus’s eyes and pupils are more developed, and it has more body fat.

What happens during week 33 – 34?

The fetus has a CRL of about 12 inches (30 cm).
The eyes have developed enough for pupils to constrict and dilate when exposed to light.
Lanugo is nearly all gone.

What happens during week 35 – 36?

The fetus has a CRL of about 12.5 inches (32 cm).
The fetus is considerably fatter, and the skin is no longer wrinkled.

What are the symptoms of pregnancy in the ninth month?

The growing fetus places more and more strain on your body when you’re 9 months pregnant. Common pregnancy symptoms at this time may continue through the end of pregnancy. These symptoms include fatigue, trouble sleeping, trouble holding urine, shortness of breath, varicose veins, and stretch marks. Some fetuses drop down into the lower part of the uterus during this month. This may relieve your constipation and heartburn, which is more common earlier in pregnancy. But some fetuses don’t drop down until the very end of pregnancy.

What happens in the tenth month of pregnancy?

When you’re 10 months pregnant, your fetus reaches its final stage of development and you give birth.

What happens during week 37 – 38?

The fetus has a CRL of about 13–14 inches (34–36 cm).
The fetus has a firm grasp.

What happens during week 39 – 40?

You will probably give birth around this time.

The average newborn baby weighs 7–8 pounds and is between 18–22 inches (46–56 cm) long with legs extended.
Almost all of the vernix and lanugo are gone.
It’s common for newborns to have some lanugo that disappears over the first few months of life.

What are the symptoms of pregnancy in the tenth month?

By the end of your pregnancy, your uterus has expanded from your pelvis to the bottom of your rib cage. Pregnancy symptoms in the tenth month largely depend on when the fetus drops down into the lower part of your uterus.

Shortness of breath, heartburn, and constipation usually improve when the fetus drops. But the position of the fetus lower in your pelvis causes frequent urination (peeing) and trouble holding urine (pee).

Your cervix will begin to open — dilate — to prepare for delivery. This may happen a few weeks before delivery, or it might start when you go into labor. You may feel sharp pains in your vagina as your cervix dilates.

After your newborn is delivered, the placenta and other tissues also come out of your body. This is called the afterbirth.