Three Stages of Pregnancy - First, Second and Third Trimester

Pregnancy occurs when a sperm fertilizes an egg after it is released from the ovary (ovulation). Ovulation occurs at the midpoint of menstrual cycle, and results in the egg’s migration into one of fallopian tubes where it may be fertilized by sperm.

Also Read: [Pregnancy] Important Factors You Need To Remember Before Expecting Mother

The fertilized egg then travels down into the uterus where implantation occurs. A successful implantation results in pregnancy, a process that lasts an average of 40 weeks. While the process sounds straightforward, there are many factors that can affect a pregnancy.

Women who receive an early diagnosis and prenatal care are more likely to experience a healthy pregnancy and give birth to a healthy baby.

First Trimester (week 1-week 12)

During the first trimester women body undergoes many changes. Hormonal changes affect almost every organ system in the body. These changes can trigger symptoms even in the very first weeks of pregnancy.

Other changes may include:

Extreme tiredness
Tender, swollen breasts
Upset stomach with or without throwing up (morning sickness)
Cravings or distaste for certain foods
Mood swings
Constipation (trouble having bowel movements)
Need to pass urine more often
Headache
Heartburn
Weight gain or loss.

Prenatal Tests

Here are some tests women may undergo during the first trimester of pregnancy.

3D and 4D Ultrasounds: 3D and 4D ultrasounds are optional. They’re not standard prenatal tests.
Chorionic Villus Sampling (CVS): Chorionic villus sampling (CVS) is a type of prenatal test done during the first trimester to look for problems with the fetus.

Health Concerns

Dealing with Morning Sickness: For many women, the toughest part of early pregnancy is morning sickness.
Hyperemesis Gravidarum: Hyperemesis gravidarum is extreme, persistent nausea and vomiting during pregnancy. It can lead to dehydration, weight loss, and electrolyte imbalances.
Blighted Ovum: A blighted ovum occurs when a fertilized egg implants in the uterus but doesn’t develop into an embryo. It is also referred to as an anembryonic (no embryo) pregnancy and is a leading cause of early pregnancy failure or miscarriage. Often it occurs so early that women don’t even know they are pregnant. A blighted ovum causes about one out of two miscarriages in the first trimester of pregnancy. A miscarriage is when a pregnancy ends on its own.
Abdominal Separation: Abdominal Separation (also called Diastasis Recti) can make a vaginal birth difficult.
Common Pregnancy Pains B: Body is constantly changing during pregnancy, which may cause discomfort.
Bleeding During Pregnancy: Bleeding during pregnancy is common, especially during the first trimester, and usually it’s no cause for alarm, but sometimes can be a sign of something more serious.
Anemia: It’s normal to have mild anemia when women are pregnant. But they may have more severe anemia from low iron or vitamin levels or from other reasons.
Ectopic Pregnancy: An ectopic pregnancy is a life-threatening condition that requires emergency treatment. It predominantly occurs when the embryo implants in one of the fallopian tubes instead of the uterus.
Multiple Pregnancy: If women are pregnant with more than one fetus, one can expect to have the same symptoms as those of a pregnancy with one fetus (called a singleton pregnancy). But the symptoms may happen earlier and may be worse.
Gestational Diabetes: Diabetes that develops during pregnancy is a relatively common complication of pregnancy, affecting about 4% of all pregnant women.
Miscarriage: Most miscarriages happen during the first three months of pregnancy.

Second Trimester (week 13-week 28)

Most women find the second trimester of pregnancy easier than the first. But it is just as important to stay informed about pregnancy during these months.

Women might notice that symptoms like nausea and fatigue are going away. But other new, more noticeable changes to body are now happening.

As body changes to make room for growing baby, women may have:

Body aches, such as back, abdomen, groin, or thigh pain
Stretch marks on abdomen, breasts, thighs, or buttocks
Darkening of the skin around nipples
A line on the skin running from belly button to pubic hairline
Patches of darker skin, usually over the cheeks, forehead, nose, or upper lip. Patches often match on both sides of the face. This is sometimes called the mask of pregnancy
Numb or tingling hands, called carpal tunnel syndrome
Itching on the abdomen, palms, and soles of the feet.

Prenatal Tests

Here are the prenatal tests women may face in the second trimester of pregnancy.

Amniocentesis
Amniocentesis is performed to look for certain types of birth defects.
Quad Marker Screen
The quad marker screen predicts the likelihood of certain problems occurring with a pregnancy.
Glucose Screening
All women should be screened for gestational diabetes during pregnancy.

Health Concerns

Back Pain in Pregnancy: At some point in pregnancy between morning sickness and labor pains, women may experience another unwelcome aspect of being pregnant which is back pain.
Preeclampsia and Eclampsia: Formerly called toxemia, preeclampsia is a condition that pregnant women develop. It is marked by high blood pressure and a high level of protein in the urine. Preeclamptic women will often also have swelling in the feet, legs, and hands. This condition usually appears during the second half of pregnancy, often in the latter part of the second or in the third trimesters, although it can occur earlier. If undiagnosed, preeclampsia can lead to eclampsia, a serious condition that can put women and their baby at risk, and in rare cases, cause death. Women with preeclampsia who have seizures are considered to have eclampsia.
Heartburn During Pregnancy: Heartburn is an irritation of the esophagus that is caused by stomach acid and is a common part of pregnancy.
Placenta Previa : When the placenta blocks the cervix, it is called placenta previa.
Round Ligament Pain: Round aligament pain is a sharp pain or jabbing feeling often felt in the lower belly or groin area on one or both sides.

Third Trimester (week 29-week 40)

Some new body changes women might notice in the third trimester include:

Shortness of breath
Heartburn
Swelling of the ankles, fingers, and face.
Hemorrhoids
Tender breasts, which may leak a watery pre-milk called colostrum
Trouble sleeping
The baby “dropping”, or moving lower in abdomen
Contractions, which can be a sign of real or false labor.

Prenatal Tests

Third Trimester Tests: During Pregnancy These tests are common in the third trimester of pregnancy.

Urine Tests: At every appointment, women’ll give a urine sample to be screened for glucose (elevated levels can be a sign of gestational diabetes) and protein (a possible indication of preeclampsia or a urinary tract infection). If either shows up in their urine, their doctor will likely order additional testing.
Ultrasound: A more detailed ultrasound anatomy scan (also called a level two ultrasound) is performed between weeks 18 and 22.The ultrasound technician will also check amniotic fluid levels, placenta location and fetal heart rate. If necessary, a late-pregnancy ultrasound can check for pre-term labor by measuring cervix length.
Amniocentesis: Recommended for women overage 35, this test, performed between weeks 15 and 20, analyzes amniotic fluid from the uterus for Down syndrome, genetic diseases such as Tay-Sachs and sickle cell anemia, and neural tube defects like spina bifida. It also can be used after week 32 to determine if baby’s lungs are mature enough to function outside the womb.
Glucose Tolerance Test: Between weeks 24 and 28, almost all women are screened for gestational diabetes mellitus (GDM). If women have specific risks, they might take it earlier. The test can’t diagnose GDM, but will determine whether further testing is necessary.
Group B Step Test: This test, given to all women around week 36, screens for harmless bacteria in the rectum and vagina that can be dangerous if transmitted to baby during delivery.
Nonstress Test: If they are overdue or at risk of premature labor, or if there are signs of fetal distress, doctor may perform a nonstress test to measure fetal heart rate and movement and uterine activity. This test can be done anytime after 24 to 26 weeks, but is most commonly performed late in the third trimester.
Biophysical Profile: Usually performed with the nonstress test in the third trimester, this profile shows the baby’s heart rate, activity level, breathing movements, muscle tone and the amount of amniotic fluid in the uterus.