First Trimester


The 13th week of pregnancy is the end of the first trimester. You can start experiencing pregnant symptoms including breast tenderness and nausea. The process of fertilization initiates fetal development. By the thirteenth week's end, every organ and system in its body is growing. As soon as you discover you are pregnant, choose a pregnancy care professional.


What is the first trimester of pregnancy?

There are three phases or trimesters to pregnancy. Every trimester lasts roughly three months, or thirteen weeks. A 40-week pregnancy, or nine to ten months, is considered full-term. You will be informed by your healthcare professional about fetal development in terms of weeks. The 13th week of pregnancy is the end of your first trimester.

Although it may seem unusual, the first day of your last menstrual cycle is actually when your pregnancy begins. This is referred to as the pregnancy's gestational age. Your due date is determined by a pregnancy care professional by adding 40 weeks to the first day of your most recent menstrual cycle. This implies that you are approximately four weeks advanced by the time you find out you are pregnant. This can be really perplexing!


Understanding weeks of pregnancy

Your regular menstrual cycle includes the first two weeks of pregnancy; the first is your period, and the second is ovulation. Your egg enters your uterus through your fallopian tube when you ovulate. When it comes into contact with sperm, the two join to form conception (fertilization).

The fertilized egg makes its way to your uterus during the third week of your pregnancy. It divides into additional cells as it descends to your uterus. It attaches itself into your uterine lining once it gets there. This sets off a sequence of events that alert your body to the fact that you are pregnant. Most women who skip their period later test positive for pregnancy.

How long is the first trimester?

Before you become pregnant, the first trimester starts. It lasts until the thirteenth week of pregnancy, beginning on the first day of your last menstrual cycle.


What can I expect in my first trimester?

During the first trimester of pregnancy, there are a lot of physical and psychological changes. It can be a very confusing period, and you could have a lot of questions running through your head. In addition, your hormones are hyperactive. Your body really produces more estrogen during a single pregnancy than it does in all of your non-pregnant years. Certain uncomfortable pregnancy symptoms may result from this hormonal surge. You can experience irritability, bloating, and fatigue. Even though you might not have noticed a noticeable baby bulge just yet, your uterus is growing and your blood volume is rising.

It's acceptable to experience mixed emotions. As you manage your pregnancy journey, talking to your friends, partner, or healthcare professional may make you feel better.


What should I do in my first trimester?

The first trimester of pregnancy is crucial. Even though you may not feel or appear pregnant, a lot is changing.

You should locate a healthcare or pregnancy care provider as soon as possible if you don't already have one. Pregnancy problems can be avoided by seeking care early on. Prepare a list of your queries or worries so you know what to bring to your initial consultation. To find out what to anticipate and where to receive care, ask your health insurance about pregnancy coverage. There are organizations and initiatives that can assist you in getting prenatal care if you don't have health insurance.


Pregnancy care professionals come in various forms and look after you throughout your pregnancy, labor, delivery, and postpartum. These include midwives, obstetricians, and occasionally primary care physicians. Apart from choosing a prenatal care provider, you might also think about where to give birth. While hospital births are the norm for most pregnancies, some women opt for home births or birthing centers.

It's a good idea to consider your general health and any lifestyle adjustments you might need to make now that you're expecting. Consider the effects of pregnancy, for instance, on your daily routine, habits, finances, and place of employment.






How does the fetus develop in the first trimester of pregnancy?

A number of things happen throughout the first trimester. When sperm fertilizes an egg, a lot of things happen inside your body that you cannot see.


Weeks one to four of pregnancy

In the initial month of gestation, multiple significant structures develop. These formations are just little groups of cells that eventually develop into the placenta, umbilical cord, and amniotic sac. The fetus produces a tube that houses its circulatory system, brain, and spinal cord. Shapes emerge: a face, eye circles, and the start of a mouth.

The embryo is tiny than a rice grain, measuring about a quarter of an inch in length.


Weeks five to eight of pregnancy

The sixth week of pregnancy marks the beginning of the development of several key organs, including the fetal heart, lungs, ears, arms, and legs. Tissue starts to give way to bones. Though it still has a big head compared to the rest of its body, it now has a more human appearance. The lips, nose, and face of the fetus are unique. Some healthcare professionals perform an early ultrasound to check for a heartbeat at this period.

The embryo develops into a fetus by the conclusion of the eighth week of pregnancy. It's roughly the size of a raspberry, or one inch long.



Weeks nine to 12 of pregnancy

Toes, fingers, and nails will be present in the fetus by the end of your first trimester. It will open and close its mouth and hands to begin moving. The stomach and urinary systems of the fetus are also completely operational. Your doctor can use a Doppler ultrasound to hear the heartbeat of the fetus at about 12 weeks of pregnancy. At this point, it also has a vagina or a penis (although an ultrasound won't show this).

The fetus is about the size of a plum by the time the 12th week of pregnancy ends, measuring between 3 and 4 inches in length. It has an ounce or so in weight.


Why is the first trimester of pregnancy so critical?

Since most of the fetus's major organs and bodily systems are still developing, the first trimester is crucial. During this period, a fetus's growth and development can be seriously harmed by toxins, dangerous chemicals, and infections. It might make your child more likely to be born with a congenital condition.


What are the most common symptoms during the first trimester?

  • Every individual and every pregnancy is different. Most pregnancy symptoms are brought on by an increase in hormones. Among the most typical are:

  • Breast pain: Hormones can cause your breasts to feel heavy and sensitive. It is typical to require larger bra sizes prior to the conclusion of the first trimester. Your breasts' increased blood flow may cause the veins to appear more visible. Your nipples may change or your areolas may become darker as further breast changes.

  • Morning sickness: This is one of the most obvious indicators of an early pregnancy. It can endure all day and all night, despite its name. Consider consuming bland, low-fat foods or smaller meals. Some persons who consume meals containing ginger experience alleviation.

  • Changes in mood: You can experience an emotional rollercoaster due to the abrupt surge of hormones. In a half hour, you could go from feeling nervous or afraid to happy or emotional. Discussing your feelings with a friend or your partner could be beneficial.

  • Feeling worn out: Your first trimester of pregnancy is a time when your body is working very hard. You can feel really exhausted after this. Make sure you get enough sleep. The majority of people regain some energy in the second trimester.

Urging: Your uterus starts expanding to accommodate the growing baby. It can start to put pressure on your bladder, making urination more frequent.

Hormones during pregnancy cause your skin to produce extra oil, which can lead to acne or other skin problems. For some people, this can result in blocked pores and acne. While some skin disorders can develop at any time during pregnancy, the majority do so in the second or third trimester.

Mild dyspnea: Light exercise may cause you to experience mild dyspnea.

During pregnancy, your heart pumps blood more vigorously. This could result in a faster heartbeat and increased susceptibility to energy loss. Recognize the strain pregnancy places on your body and take breaks when needed.


What tests will I have in the first trimester of pregnancy?

Prenatal exams, screenings, and other diagnostics contribute to the health of both you and the developing fetus. Prenatal care is the term used to describe medical attention given during pregnancy. Prenatal care appointments are crucial because your prenatal care provider answers your questions, checks and screens you, and talks with you about what to expect during pregnancy and delivery.

Your initial pregnancy checkup

You will have two or three prenatal appointments in the first trimester. Depending on your provider or whether your pregnancy is high-risk, this may change. Your family's medical history that may have an impact on your pregnancy, as well as your own, will likely be covered in addition to your obstetrical and gynecological history (previous pregnancies and deliveries). In order to ensure the health of both you and the developing fetus, this appointment is quite thorough.

  • Your due date will be determined by your provider at your initial prenatal appointment. Additionally, you should anticipate them to do the following:

  • a physical examination that involves taking your blood pressure and weight.

  • a pelvic examination.


  • a Pap test, if one is scheduled for you.


  • examinations to detect specific STIs (sexually transmitted diseases).


  • Examine your urine for protein, microorganisms, and glucose (sugar).


  • Get blood tests to screen for specific diseases, the Rh factor, hormone levels, and iron levels.


  • Verify the baby's heart rate.

During your initial visit, some medical professionals use transvaginal ultrasounds to verify your pregnancy and determine the size and heart rate of the fetus. This ultrasound can also detect multiple pregnancy. Your healthcare provider inserts a wand within your vagina during a transvaginal ultrasound. In their first trimester, most expectant mothers are granted at least one ultrasound; however, the precise time varies based on your healthcare provider. You might be offered several first-trimester ultrasounds if you are expecting multiples.

Throughout your pregnancy, your doctor could advise additional screenings. Screening tests determine the risk of certain health issues for both you and the fetus. Your screening findings may indicate that you require diagnostic testing. Diagnostic examinations validate or rule out medical issues. 

For the purpose of identifying chromosomal problems such as Down syndrome, your provider could recommend a screening during the first trimester. Discuss the recommended screenings with your provider.


What should I not do in the first trimester of pregnancy?

  • It's common to need to adjust your lifestyle after learning you are pregnant. These modifications contribute to ensuring everyone's health. The following items are things you should stay away from in the first trimester of pregnancy:

  • Beverage.

  • Smoking and tobacco use.


  • illicit substances, such as opioids.


  • Participate in contact sports, such as football, or exercises that exert pressure on your abdomen.


  • foods such as sushi (raw fish), mercury-filled seafood, undercooked or raw meats, lunchmeat, and unpasteurized milk, cheese, or juice.


  • Saunas and hot springs.


How do I take care of myself in the first trimester of pregnancy?

  • It's critical to maintain your health over the entire three trimesters of pregnancy. The following advice will help you maintain your health during the first 13 weeks of pregnancy:

  • Try to keep as busy as you can. When exercising, pay attention to your body and take a break if you start to feel uncomfortable. During pregnancy, you might need to adjust your fitness regimen.

  • Take a folic acid-containing prenatal vitamin.


  • Consume a range of nutritious foods, such as whole grains, meat, eggs, veggies, and fruits.


  • Get lots of sleep.


  • Sip a lot of water.


  • Keep all of your appointments related to pregnancy.


Is it normal to bleed during the first trimester of pregnancy?

In the first few weeks of pregnancy, light bleeding or spotting is generally acceptable. Implantation bleeding is a condition in which a fertilized egg burrows into the lining of your uterus. If your bleeding persists for more than a day or is severe, contact your prenatal care provider.


What prenatal vitamin should I take?

The fetus is supported during its growth and development by the vitamins and minerals in your diet and prenatal supplements. As soon as you start attempting to become pregnant, the majority of physicians advise taking a prenatal vitamin. Iron, calcium, and folic acid-containing vitamins promote a healthy pregnancy. If you're unclear about which prenatal vitamin to take, consult your healthcare professional.


Can I drink caffeine during pregnancy?

The majority of medical professionals advise pregnant women to consume no more than 200 mg of caffeine per day. That equates to roughly 12 ounces of coffee or three Mountain Dew® cans. This is because caffeine can accumulate in a fetus's body and lead to difficulties because the fetus is unable to metabolize it.


When should I call my pregnancy care provider during the first trimester?

  • Make an immediate call to your provider if you have:

  • a temperature that is greater than 100.4 °F.

  • severe bleeding or strange discharge from the vagina.


  • severe stomach discomfort or cramping in your arms, legs, or tummy.


  • persistent diarrhea or vomiting.


  • dizziness or fits of fainting.


  • swelling in your face, hands, or fingers.


  • spots or fuzzy vision in front of your eyes.