Family Life

Your Guide In Knowing The First Trimester Is How Long And More

Knowing and understanding the first trimester is how long it is key to ensure your baby’s safety in your belly. Whether you are a first-time mom or a new mom again, it is important to be well-informed about the different stages of pregnancy for you and your baby’s safety.


Becoming pregnant is one of the best blessings ever. Needless to say, it is one of the most precious times in a woman’s life. After all, not all women are given that rare opportunity to carry a baby in her womb.


It is common especially among first-time moms to ask questions like the first trimester is how long, what the changes should a mom-to-be expect during these times, how about the baby, what does the baby look like at this point in time?


We ask such questions because as we know, the first trimester is critical. It is considered as the hardest part of pregnancy. Apart from adjusting to the changes happening in your body, you have to ensure that you do what needs to be done to ensure that your baby is safe and that the pregnancy pushes through.


With that said, we shall be sharing with you not just about how long is the first trimester of pregnancy, but also other essential information that every mom-to-be needs to know in this particular stage.




Before we specifically talk about the first trimester is how long and all the other stuff that you need to know during this stage of pregnancy, it is first important to understand that pregnancy comes in three trimesters.


Yes, you read it right. Pregnancy has three trimesters or stages. Each of these is marked by specific fetal developments. Generally speaking, a pregnancy is considered full-term when you reach 40 weeks. However, in most cases, women give birth sooner – usually around 37 to 39 weeks, which is considered normal by healthcare professionals. But those infants delivered earlier than 37 weeks though are considered premature babies, which, according to experts may have problems with their growth and development. Some may even experience difficulty in digesting as well as breathing.


To help you understand or at least have an idea about how long each trimester is and what to expect in each trimester, here’s a piece of information from the University of California San Francisco Health:


– First Trimester (0 to 13 Weeks)


As we earlier mentioned the first trimester is critical. It is considered the most crucial times, especially on your baby’s development. According to UCSFH, it is during this period when your baby’s structure, as well as his or her organ systems, develop. In most cases, it is during this stage of pregnancy when there is a higher risk of miscarriage as well as the possibility of birth defects.


Furthermore, the first trimester is the time when your body goes through major changes. These changes are usually caused by various symptoms such as nausea, breast tenderness, fatigue, as well as frequent urination.


While these are considered normal and common pregnancy symptoms, it is important to note that every woman and every pregnancy is unique. For instance, while some women may feel terrible during this stage, others may feel an increased level of energy during this time.


– Second Trimester (14 to 26 Weeks)


The second trimester of pregnancy is usually a more relaxed time. In fact, it is often called as the “golden period” because most of the not so good things you experience during the early stage of pregnancy usually disappear once you hit your second trimester.


During this time, you are less likely to experience nausea and other pregnancy symptoms. It is also during this period when you get to have a better sleep pattern, as well as an increased level of energy. But just as all these early pregnancy symptoms disappear, it is also common among pregnant women on their second trimester to experience a whole new set of pregnancy symptoms like abdominal pain, leg cramps, heartburn, as well as back pain, and constipation.


Usually, it is during this month that pregnant women feel more “normal”. It’s also easier to do things during this period as compared to the first and the last trimester.


The second trimester is also an exciting phase of pregnancy as somewhere between 16 and 20 weeks, moms-to-be may feel their babies’ first fluttering movements.


– Third Trimester (27 to 40 Weeks)


The third trimester is considered as the final or last stretch of pregnancy. It is during this time when moms-to-be become more excited at the same time anxious about giving birth to their little one.


Although an exciting and thrilling time, pregnancy symptoms do not end at this point. In fact, it’s either you experience some of the symptoms you had the past two trimesters or you go through a completely different set.


Some of the common physical symptoms a pregnant wan experience during this stage of pregnancy include shortness of breath, urinary incontinence, sleeping problems, hemorrhoids, frequent urination as well as varicose veins. Most of these symptoms occur because of the increasing size of your uterus. During the third trimester, a woman’s uterus expands from approximately 2 ounces before pregnancy to 2.5 pounds at the time of delivery.




As mentioned, a standard full-term pregnancy is measured at 40 weeks, however, that is usually not exactly as most mommies give birth even before they reach the 40th week. Apart from babies being notorious for not coming out on their expected due dates, the trimester system can be a little confusing as well. Technically speaking, a woman is not considered pregnant until she is about two weeks in.


The start of pregnancy is measured starting from the first day of your last menstruation. Usually, ovulation happens about two weeks after that, which, according to experts is when the fertilization of the egg takes place and immediately followed by the implantation of the embryo.


In most cases, women find out that they are pregnant four weeks or more after their last menstrual period. That is actually considered as the earliest that an at-home pregnancy test is able to detect pregnancy. To put it simply, most women if not all go through the first four weeks of their pregnancy without even knowing that they are already pregnant.





To answer the first trimester is how long, as mentioned above, it lasts for 13 weeks. The first trimester is counted from 0 up to 13 weeks according to the University of California San Francisco Health or UCSFH.


To be more specific, the first trimester starts on the first day of your last period (yes, whether you are already pregnant by then or not), and then it lasts until the end of week 13. Basically, this means that by the time you learn about your pregnancy, you might already be around five or six weeks pregnant! That is if you have regular periods. Women with irregular periods may have a hard time though.


Just so you know, a lot of things happen during the first three months of pregnancy. During this time, the fertilized egg rapidly divides into layers of cells, and then implants in the wall of a woman’s womb where it is carried all throughout the pregnancy. The layers eventually become an embryo. The embryo is a term that refers to the baby during this stage.


During the first trimester of pregnancy, the baby grows faster compared to any other time. Usually, you will first hear your baby’s heartbeat by around six weeks. At 12 weeks, your little one’s bones, muscles, and all the other organs of his or her body get formed. By the end of the first trimester, through an ultrasound, you will find your baby looking like a tiny little human being, which is called a fetus. Guess what? During this time your baby may already be practicing how to swallow! Amazing right?




The moment you get a positive result in your pregnancy test, take a while to take it all in and then relax a bit. As much as you can, celebrate with your husband or partner, as well as your family and friends about such a piece of amazing news as it won’t be long until you start noticing the first few symptoms of pregnancy.


During the first trimester of pregnancy, you may experience symptoms, which include morning sickness, bloating, exhaustion, breast tenderness, nausea, as well as moodiness. Although you will not look like you are pregnant yet, you will definitely feel the effects.


While it is common among pregnant women to feel such pregnancy symptoms, others may not feel it that much. That is normal though as every woman, every body, and every pregnancy is totally different.


If you are wondering about the first trimester is how long, it will last for 13 weeks. So, yeah, for some it takes that long before pregnancy symptoms end, however, others may experience lesser symptoms earlier.


The first trimester is critical as it is during this stage that your little one is still developing. The risk of miscarriage as well as developing birth defects is higher during this stage, which is why women are told to be extra careful during this stage.


To help ensure the baby’s safety, as well as proper growth and development, women, who are in their first trimester of pregnancy are highly advised to eat nutrient-dense food, take prenatal vitamins, stay hydrated, and of course, to take all necessary measures to keep a healthy body.


During this time, extra calories are not needed yet. In addition, tobacco, chemicals, as well as alcohol must be highly avoided. Women who are in their first trimester are also advised to take more rest and sleep, at the same time, try to do exercise regularly (make sure though to consult your doctor before doing any exercises to ensure it’s safe for you and your baby).


While it looks like just a very short period of time, your baby will, in fact, go through a phenomenal amount of growth and change. From a single-cell zygote, it will grow into a miniature person in just a few months!


During the first trimester, your baby starts to have a heartbeat, his or her limbs grow, and it is also during this period when your little one develops his or her bones, nails, hair, brain, and other internal organs.




During the first trimester, a lot of things are happening in your body, needless to say, changes happen here and there. If you are a first-time mom-to-be, you may be wondering, of all the signs and symptoms, what are normal and what are considered as not normal.


With that said, here are some symptoms that may be a cause of concern:

  • Heavy vaginal bleeding
  • Sudden thirst
  • Painful urination
  • Severe abdominal pain
  • Vision disturbances
  • Fever over 101.5 F, chills and/or backache
  • Severe puffiness in the hands/face


If you experience any of these, it is best to call your doctor immediately. If your doctor is not available, you might as well head to the nearest emergency room instead.


Know more about the first trimester of pregnancy on below video from MountainStar Health:




Apart from knowing the first trimester is how to log, and other vital information that you should know about this specific phase of pregnancy, you must also be aware of the other important things that you must do once you get a positive result for pregnancy.


With that said, here are some first trimester to-dos:


  1. Choose Your Practitioner.


Pregnancy is one of the most important phases in a woman’s life. Needless to say, it’s one of the most personal and sensitive moments in your life. Thus, it is important to choose the right person who will be there from you, taking care of you and your baby from day one until birth.


There are several practitioners you can choose for your pregnancy. You can choose from an OB gynecologist, midwife, as well as a family physician. Choosing the right one can be crucial, so just take your time to consider all options available, and eventually pick the right practitioner to cater to your needs.


  1. Schedule Your First OB-Gyn Visit.


During your first visit, your doctor will most likely check your medical exam as well as to conduct a thorough physical exam. He or she may also request you to undergo a series of tests to ensure you are well-fit.


You will most likely go through an initial ultrasound to confirm your little one’s heartbeat, as well as your date of pregnancy. It will also help determine if things are progressing the way they should.


Apart from the tests and all, it’s also a good time for you to ask questions regarding pregnancy especially if you are a first-time mom.


  1. Start Taking Prenatal Vitamins.


If you haven’t started yet, make sure to immediately start taking one upon confirmation of your pregnancy. Taking prenatal vitamins during the first trimester has been shown to greatly reduce the risk of neural tube defects.


  1. Check Your Insurance Options.


These days, the cost of pregnancy can be quite expensive. Needless to say, you have to base it on a number of factors. Thus, take this time as the perfect time to sign up for a plan or review the terms of your policy if you already have one. Make sure to focus on your premiums as well as your co-insurance to keep your overall payment costs as low as possible.


  1. Make A Budget.


From the moment you find out your pregnant expenses will slowly pile up. Thus, make sure to reevaluate your monthly expenses from time to time. Also, consider thinking ahead by learning the cost of having a little tiny human around, and then set up your monthly budget.


  1. Consider Taking Genetic Tests.


Today, test like nuchal translucency screening is usually done when you reach your 10th to 13th week of pregnancy. It’s a test done to check if your baby has Down syndrome or congenital heart defects. Depending on your risks, your healthcare practitioner may recommend NIPT around 9th week and/or invasive but more conclusive prenatal tests.


  1. Start Eating Right.


Make sure to talk to your healthcare practitioner about the food that you must avoid when pregnant. At the same time, consult about what specific food is great for you and your baby. Also, make sure that as soon as you find out your expecting, you cut down your caffeine intake. Having a healthy diet while pregnant will not only benefit you but most importantly, your little one.




Getting pregnant is one of the greatest joys of every woman. It’s such a wonderful phase in a woman’s life. So, if you are positive for pregnancy, you must feel really blessed! After all, as we mentioned earlier, not all women are given the chance to bear a child.


To ensure that you get to give your best possible care for your tiny little human, it is vital to know details like the first trimester is how long and another equally important first-trimester pregnancy-related information.