Symptoms, Risks & What to Expect in the Early Weeks of Pregnancy
Even with planning, the changes of pregnancy can feel sudden. So much happens with fetal development and hormones in the first trimester, which lasts Weeks 0-13. Use this guide to understand early common symptoms and signs of pregnancy, changes in your baby, and when to seek medical care.
Knowing You’re in the First Trimester: Confirming and Dating Pregnancy
First Trimester Pregnancy Symptoms
- What changes should I expect to see in my body?
- What major milestones are occurring in my baby’s development?
Concerning signs in early pregnancy
- Risk Prevention and First Trimester Pregnancy Challenges
- Things to avoid in early pregnancy
- Pregnancy loss and miscarriage realities
Knowing You’re in the First Trimester: Confirming and Dating Pregnancy
Some pregnancy symptoms and changes are more frequent or intense at different stages, so it’s helpful to confirm how far along you are when planning for medical care, work, and other lifestyle adjustments for a healthy pregnancy.
You may already be sure you are pregnant, or perhaps you are just starting to experience some signs that you might be. If you have not yet confirmed your pregnancy, you might want to check out overview of early pregnancy symptoms for more information on early signs of pregnancy, accurate pregnancy testing, and estimating due dates.
First Trimester Pregnancy Symptoms
Pregnancy symptoms can be overwhelming, even if you are excited to be pregnant! Metabolic, hormonal and anatomical changes are very real and put new demands on your body in the first trimester. Some early changes are temporary, while others may last all through pregnancy - framing this experience as a long term journey of body, heart and mind can be helpful in planning for the safest, best possible outcome for you and your family.
Existing health complications, trauma history, and current lifestyle can all influence your experience of pregnancy symptoms - understanding what is occurring in your body may help you to feel more confident and illuminate steps to support your comfort and long term health. Speak with your prenatal health care provider about any major changes that could help you to alleviate discomfort and avoid major risk factors.
What changes should I expect to see in my body?
While you can’t feel your baby’s early movement in-utero during the first 12 weeks, your body will be changing dynamically to support their nourishment. This includes changes in your hormone levels, increased blood flow, and shifts in digestion, immune, and stress responses. We’ll cover some of these elements below and offer the reminder that you may experience these differently than your peers or relatives.
Just a few of the hormones involved in pregnancy and the changes associated with them are listed here:
- Progesterone is made by the ovaries and the placenta during pregnancy. This hormone helps your uterus prepare to protect and nourish a fertilized egg, and by facilitates muscle relaxation to support your growing uterus as pregnancy continues. It can also make you feel sleepy.
- Estrogen is also produced by the ovaries and later by the placenta, and supports increased blood flow and immune function during your pregnancy. Later, estrogen promotes the growth of breast tissue and milk production for breastfeeding
- Oxytocin is a neurotransmitter associated with bonding, attachment, and trust, and also, acting as a hormone, causes contractions of the uterus - it even causes lighter contractions during orgasm and menstruation! Since it’s related to social bonding as well as physical mechanisms, oxytocin levels in the body and the brain increase throughout pregnancy and can influence feelings of sensitivity, protective instincts, love, calm, and connection. It can also influence metabolism, digestion and immune response and is a major factor in labor, birth, and lactation.
In medical research, it’s estimated that about 60% of pregnant people experience symptoms of pregnancy as early as 5-6 weeks, and 90% by 8 weeks. Check out this blog post for the most common early symptoms - below we list other symptoms typical of the first trimester.
- Bloating, heartburn and indigestion: Eating small meals, avoiding acidic foods like coffee or hot sauce, and using the bathroom frequently may help with these symptoms. Long-term use of antacids can actually increase acid reflux so consult with your care provider and discuss minimum effective dosage if this remedy seems best for you.
- Constipation and/or hemorrhoids: Pregnancy hormones relax the digestive tract, while a growing uterus puts additional pressure on your system. Eating more fiber can usually relieve constipation, and your prenatal health care provider may recommend a pregnancy-safe stool softener if needed. To help with hemorrhoids, address constipation, avoid straining on the toilet and consider buying a stool to assist a semi-squatting position while eliminating.
- Cardiovascular health: Elevated pulse, changes in blood pressure and/or dizziness during pregnancy can occur, due in part to increased blood volume and dilated blood vessels in the first weeks. If you are experiencing severe dizziness, sudden swelling, or a quickening pulse accompanied by sudden pain, seek medical attention.
- Skin changes: Varicose veins (veins with a bulging appearance) may develop in your legs. They might feel itchy or uncomfortable - low impact exercise, limiting time spent sitting, and elevating your legs and feet may help. In general, moving positions regularly supports the higher demands of blood flow in pregnancy and can be especially supportive after a full work day.
- General increase in fluids: Blood volume and mucus production all increase in pregnancy - this supports the delivery of nutrients to you and your baby, your hormonal and brain activity, and essential immune and protective factors for your organs and daily functioning. This might also mean an increase in vaginal discharge. Drink plenty of water to support your own system as well as the healthy function of your baby’s environment, which is mostly made of water and supportive cells from your own body.
What major milestones are occurring in my baby’s development?
The changes of pregnancy are designed to support your baby’s growth and development - some will cause discomfort, and others can be quite enjoyable. In either case, understanding the changes happening for your baby in the first trimester can help you to appreciate the hard work that your body is doing in a typical low-risk pregnancy.
Developmental is best supported in a pregnant person who is hydrated, well-nourished, getting enough sleep, and taking a prenatal vitamin with folic acid - just to provide minimum nutrition on those days when it’s hard to eat well. Other than that, nature generally takes care of the rest! The three components below form to create an environment to support growth after your fertilized egg implants into the uterine wall and becomes an embryo.
- Amniotic sac: This fluid-filled sac protects and regulates the temperature of the baby. The fluid is produced by the baby and the amnion, a membrane covering the placenta. It mostly consists of water, proteins, white blood cells, electrolytes, and some special fats and carbohydrates that aid fetal growth.
- Placenta: During pregnancy, your body creates an entirely new temporary organ - the placenta. Your placenta brings nutrients to and takes waste away from your baby via fetal blood vessels that grow from the umbilical cord. Not all medications or substances are filtered out by the placenta, so check with your care provider about safe use in pregnancy.
- Umbilical cord: A blood vessel-rich, cord-shaped structure connecting your baby to the placenta. This cord delivers oxygen-rich blood and other essential components to your baby during pregnancy and in the period immediately after birth.
First trimester developments are one of the reasons for fatigue - it’s simply a lot to build in a short amount of time! In the first 8 weeks, a few key developments occur and the embryo reaches 1 inch in length:
- All major organs start taking shape, including your baby’s sex organs.
- Limbs start to grow longer, fingers and toes start to develop.
- Eyes and eyelids take shape and move forward on the face from the sides of the head.
- The main structures of the heart start to beat rhythmically.
- The early structures of brain and spine function develop - research shows that standardized folic acid supplementation is a critical protective factor for healthy development.
Between 8 and 12 weeks, a more familiar form appears and we refer to the baby as a fetus. Key developments include:
- Sex organ formation continues - by 18-20 weeks, your provider can confirm your baby’s sex
- Nerve and muscle movement becomes coordinated - a fetus this age can make a fist.
- It is notable that while the nervous system continues to develop and reflexes are observed, current evidence suggests that because the brain and nerves are not wholly connected until closer to 28 weeks, fetuses do not feel sensation the way adults do while still in the early stages of development.
- The formation of arms, legs, fingernails and toenails continues.
- Bones start to replace cartilage.
- Eyelids are fully formed and now cover the eyes. Eyes will remain closed until 28 weeks.
Concerning signs in early pregnancy that require medical care
As you move through your pregnancy journey, knowing your body and developing an awareness of concerning symptoms in pregnancy is important.
- Vaginal bleeding: Early spotting in pregnancy can be a sign of implantation bleeding, but all vaginal bleeding in pregnancy merits a discussion with a prenatal health care provider. Bleeding heavier than spotting or accompanied by any moderate pain (especially if one-sided) may be a sign of an ectopic pregnancy (a pregnancy outside of the uterus.) Overall, ectopic pregnancies are rare (about 1-2% of pregnancies) but it is considered a gynecologic emergency that needs to be addressed immediately. Bleeding may also be a sign of a miscarriage (or early pregnancy loss), or an infection of the cervix.
- Nausea and vomiting: If you’re unable to keep food or water down despite measures such as small, frequent meals, plain foods, and provider-approved medications, contact your prenatal health care provider for guidance.
Also keep in mind that routine reasons for seeking urgent or emergent care stand true in pregnancy. Any unexplained and sustained difficulty breathing, chest pain, worsening abdominal or back pain, pain with urination or sustained fevers (body temperature >104°F), or chills should be evaluated by a medical professional.
Risk Prevention and First Trimester Pregnancy Challenges
We face risk every day in our lives, from crossing a busy street to second-hand smoke exposure. These risks may feel - and sometimes are - magnified or uniquely impactful during pregnancy. One one hand, it is reassuring to know that a healthy pregnant person’s body does a great job of protecting a developing fetus, but not everyone is low-risk, and even the healthiest pregnancies can benefit from some extra considerations and protections.
In this section we discuss those risks, as well as the challenges that do come up more commonly than may be publicly discussed, including miscarriage and pregnancy loss.
Things to avoid in early pregnancy
Someone who is pregnant will want to start ensuring that they are drinking plenty of water (8-10 glasses a day), taking folic acid with a prenatal vitamin, getting enough rest, and eating a variety of nutrients to the best of their capacity. But what about the things one should avoid or stop altogether during pregnancy?
Toxic agents that can be harmful to your baby’s development during pregnancy are known as teratogens. Teratogens act on the baby’s developing cells , and the timing of exposure often determines the severity and type of the effect. Toxins can enter your system through medications, your diet, or even chemicals that you are exposed to at home or work.
- Specific drug and medication risks can be found at the Organization of Teratology Information Specialists. The list of medications that may be dangerous in pregnancy is too long to list here, but we did want to highlight some types of medication to discuss with your health care provider.
- Certain antibiotics
- Antiepileptic drugs (AED)
- Isotretinoin (Vitamin A >10,000 mg/day)
- NSAIDs (Ibuprofen or Naproxen Sodium)
- When you are exposed to hazards at work, it is called an occupational exposure. The Occupational Safety and Health Administration (OSHA) provides recommendations for those that work in various sectors like healthcare, nail salons, and diesel exhaust exposure. Refer to the Centers for Disease Control and Prevention (CDC) for more information on other specific workplace exposures.
- Radiation exposure through X-rays or computed tomography (CT) scans can be teratogenic in excessive doses. However, imaging studies such as these may be necessary and critical during pregnancy to rule out infection, pulmonary embolism, or other dangerous conditions. Ask for information on the risks and benefits of radiation exposure before imaging. Prescribed ultrasonography and magnetic resonance imaging (MRI) are not associated with radiation exposure and are safe in pregnancy.
- Drinking alcohol during pregnancy can cause fetal alcohol syndrome (FAS), a combination of intellectual and behavioral disorders. It is also a depressant and can contribute to depression or mood disorders during pregnancy and postpartum.
- Substance use during pregnancy can result in growth restriction, cognitive disorders, preterm birth, stillbirth, and maternal death. Opioid use can additionally cause a condition called neonatal abstinence syndrome (NAS). NAS is a condition where the infant requires higher levels of medical care to address signs of withdrawal to the drug at birth.
ACOG also provides guidance for the following:
- Limit mercury exposure. Avoid bigeye tuna, king mackerel, marlin, orange roughy, shark, swordfish or tilefish. Limit consumption of white albacore tuna to 6 ounces a week. Continue eating 8-12 ounces of low-mercury fish and shellfish per week.
- Avoid lead exposure. Avoid old paint, construction materials, unregulated supplements or medicines, and items like jewelry and pottery made in foreign countries.
- Avoid high levels of vitamin A. High levels of vitamin A have been linked to severe birth defects. You should consume no more than 10,000 international units of vitamin A a day.
In every pregnancy, a person starts out with a 3-5% chance of having a baby with a congenital abnormality. Teratogens can increase this risk and negative outcomes are often dose dependent - the higher the dose, the more significant the impact. Being aware of teratogens and bringing up any concerns with your prenatal health care provider can help you minimize risk for your baby as well as your own health. You are deserving of your own attention and care - if you are feeling anxious about your risk exposure or struggling to make lifestyle changes, it may be helpful to seek counseling or additional support.
Pregnancy loss and miscarriage realities
Pregnancy loss can be incredibly difficult and lonely. If you have experienced this pain, recognizing that at least 15-20% of women will experience a pregnancy loss may be helpful to understand, but it doesn’t take away the significance of your unique story and grief.
Early pregnancy loss describes an intrauterine pregnancy that stops growing before 13 weeks. Recognize that early pregnancy losses are usually unavoidable and not the pregnant person’s fault.
If you are experiencing potential signs of a miscarriage like heavy vaginal bleeding, contact your prenatal health care provider immediately. It is important to recognize that there are no ways to stop a miscarriage once it has started.
In the event of a confirmed early pregnancy loss, you generally have three options for care:
- Observation - This refers to allowing a miscarriage to take place without any interventions, also called “expectant management”. This can mean bleeding for a few days up to 3-4 weeks.
- Medication management - Management with a combination of one or two types of medication (often mifepristone and misoprostol) can allow you to pass pregnancy tissue over the course of a few days and in the privacy of your home.
- Surgical management - Dilation and curettage, or D&C, is a procedure that can be performed in a clinic or an operating room and removes pregnancy tissue from the uterus.
Other types of pregnancy loss can occur when there is a serious medical indication such as a severe infection, or early signs of serious developmental abnormalities that impeded a fetus from developing and surviving. Sometimes a person who wants to be pregnant has to terminate a pregnancy for these or other reasons.
The grief of anyone dealing with a pregnancy loss is valid, complex, and personal, and yet many people suffer in silence because of societal discomfort with these topics. Below are some resources for supporting early pregnancy loss.
- Loss counseling with a Seven Starling coach: Some of our Seven Starling providers are trained in supporting families experiencing a pregnancy loss.
- Support groups
- National Share is a national support organization for those experiencing pregnancy loss.
- Postpartum Support International offers a pregnancy and infant loss support group.
- Hotline for pregnancy loss support: M+A offers a confidential hotline led by doctors for managing pregnancy loss during miscarriage or abortion.