The first trimester is the most significant adjustment period of your pregnancy. This episode covers everything you need to know to navigate the first trimester confidently. Learn how your baby is growing and developing vital organs and structures. Hear about common physical and emotional symptoms in the first trimester. Find out what you can expect at your upcoming prenatal appointments and key to-do items you should tackle this trimester. Plus, get tips on your partner’s role and how they can best support you in the first 12 weeks.

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Weeks 1 to 12

The first trimester of your pregnancy spans the initial twelve weeks. Pregnancy is measured in weeks leading up to the birth of your baby. Your baby is due at the start of your 40th week of pregnancy. Week one is the week of your last period before you get pregnant. You don’t ovulate and conceive until week three. This calculation uses a formula called Naegele’s rule. While it operates on some assumptions, like a 28-day cycle and ovulation on day 14, it is widely accepted in the medical community.

There is much to learn and many decisions to make throughout your pregnancy and parenting journey. The amount of information to consume can be overwhelming, especially in the beginning. Don’t worry. You have plenty of time to get everything figured out. Tuning into this podcast is a great way to start. Luckily, your instincts will kick in, and nature will arm you with tools you probably don’t even know you have yet.

Pregnancy Safety

As soon as you find out you are pregnant, you should be cautious about consuming some foods and exposing yourself to environmental dangers. This includes some obvious things like caffeine, alcohol, cigarettes, and drugs. This episode brings you up to speed on everything you need to know as soon as you find out you are pregnant. 

There is a lack of safety information on medications during pregnancy. The CDC’s Treating for Two initiative works to improve the health of women and babies by identifying the safest treatment options for common conditions before, during, and after pregnancy. Their general recommendation is to talk to your doctor. Since your baby’s systems begin developing in the first trimester, this is considered a particularly sensitive time. Discuss any prescription or over-the-counter medications with your doctor or midwife to ensure they are safe for you and your baby.

Your Growing Baby

At conception, your baby is a single cell. Your baby starts out looking like a tadpole, but as they grow, they become more human-like in appearance. During the first trimester, your baby’s organs will begin to develop, and some will even start to function.

As your baby grows, they will be busy kicking and stretching and may even have hiccups. It will still be a few months before you can feel them moving around. By the end of the first trimester, their heart beats and pumps blood, their facial features will begin to appear, arms and legs will grow longer, fingers and toes will start to form, and they will even have fingernails.

At 12 weeks, your baby weighs about half an ounce, measuring around two and a half inches from crown to rump. Babies in utero are measured from the crown of their head to their bottom since they are folded to fit inside your uterus. Once they are born, the length is measured from head to toe. Your baby is about the size of a lime or a plum at the end of the first trimester.

Common First Trimester Symptoms

Many common symptoms of pregnancy can arise in the first trimester. Everyone experiences pregnancy differently. Although you will not experience every one of these symptoms, having a basic understanding may help you cope with some uncomfortable side effects of being pregnant.

Hormonal Changes in the First Trimester

The most significant drivers of change in pregnancy are changes in hormone levels. Once an egg is fertilized, the part that will develop into the placenta starts producing the pregnancy hormone hCG (human chorionic gonadotropin). hCG is the hormone a pregnancy test detects. hCG instructs your ovaries to stop releasing eggs and triggers increased production of estrogen and progesterone. Hormones play a significant role in all aspects of your pregnancy and trigger many common symptoms. Hormones impact more than your physical health and can also affect your mental health by making your moods and emotions swing all over the place.

Physical Changes in the First Trimester

While a pregnant belly is a hallmark of being pregnant, most expecting mothers do not start to show until the end of the first or the beginning of the second trimester. It may be sooner if you are expecting twins or if this is not your first pregnancy. You should expect to gain only about 2 to 4 pounds during the first trimester.

Breast Changes

Early in your pregnancy, sensitivity, tenderness, and pain are common in your breasts. This can start one to two weeks after conception. For many women, it is one of the first signs of pregnancy. Soreness is caused by hormonal changes, retaining more fluids, and your breasts preparing for lactation. Wear a comfortable and supportive bra. See this article for an in-depth explanation of the changes you can expect with your breasts during pregnancy.

Fatigue

As your levels of progesterone increase, you may find yourself tired and wiped out. Don’t fight it. If your body is telling you it needs extra rest, listen to it. Pregnancy fatigue is most common in the first and third trimesters. Getting adequate sleep and taking care of your health may help with fatigue. Sometimes, the best thing you can do is relax, rest, nap, or go to bed early.

Morning Sickness

Morning sickness is nausea during pregnancy and can be accompanied by vomiting. This does not just happen in the morning, but can happen at any time or even all day. Morning sickness affects  60-80% of expecting mothers. This is most common in the first trimester, can start as early as one to two weeks after conception, and usually goes away after 12 weeks or when you begin the second trimester. Hyperemesis gravidarum is a severe morning sickness requiring hospitalization or treatment with IV fluids and affects .3-2% of all pregnancies. The most common statistic I see in research is around 1%.

It can be especially tough in the first trimester when you may not tell everyone you are pregnant; you feel sick, miss work, or miss out on social activities. You are going through many physical and emotional changes, and not feeling well can impact your mental health and quality of life. What helps relieve nausea for one expecting mom may not work for you. Please check in with your doctor or midwife if you struggle with morning sickness and cannot keep liquids down. See this episode for an examination of treatments to find relief.

Stuffy Nose and Pregnancy Rhinitis

Increased blood flow and hormonal changes during pregnancy cause the blood vessels in your nasal passages to swell, leading to congestion. You may be congested, snore in your sleep, and even get occasional nosebleeds. This condition is sometimes classified as pregnancy rhinitis. It is an inconvenience, but it will go away on its own eventually.

Frequent Urination

Frequent urination is one of the most common symptoms of pregnancy, especially early on. The pregnancy hormone hCG (the one that caused your pregnancy test to be positive) causes an increase in blood flow to your pelvic area. This is good for increased sexual pleasure, but not so good when running to the bathroom more frequently. Your kidneys are more efficient at ridding your body of waste, and your growing uterus is beginning to push down on your bladder. All of this adds up to more frequent bathroom breaks.

Constipation

During pregnancy, your body’s increased progesterone production relaxes your smooth muscles, including your digestive tract, which slows down digestion. On the positive side, this gives nutrients more time to be absorbed into your bloodstream and reach your baby. Unfortunately, it can also lead to constipation. Constipation symptoms include difficult or infrequent bowel movements, hard stools, and pain or discomfort in the stomach. Eating high-fiber foods, staying hydrated, and exercising can improve constipation. See this episode for more information on constipation and the safety of over-the-counter remedies.

Food Cravings

Many expecting mothers experience different food cravings during pregnancy. There is some speculation that if you crave a particular type of food, your body is trying to balance a nutrient deficiency. For example, if you are craving oranges, you need more vitamin C. Research doesn’t support that theory, and food cravings are likely psychological.

First Trimester Prenatal Appointments

Your doctor or midwife is the cornerstone of your prenatal care and birth experience. This is the expert resource you will work with throughout your pregnancy to make significant decisions. You need to see them as an integral team member and, most importantly, trust and be comfortable with them. If you do not feel supported by your current doctor or midwife, you can change providers. See this article on choosing (or changing) your doctor or midwife.

Your first prenatal visit will be around week eight. Those weeks leading up to this visit can seem like forever. This episode outlines what you should be doing before your first appointment. The first steps are to confirm your pregnancy and determine your due date. Your doctor or midwife will likely administer a pregnancy test and perform a transvaginal ultrasound. Your due date is determined using a calculation based on your last menstrual period and ultrasound measurements. While a due date is rarely the date your baby will show up, it is a relatively close estimate.

Prenatal appointments are every four weeks from your first appointment through the second trimester. There are routine things that you can expect to happen at each checkup. Your care provider should ask how you feel and if you have any questions. It is essential to communicate to make sure you understand everything. Here are five tips to make the most out of every prenatal appointment.

You will have to step on a scale at every appointment. The American College of Obstetricians and Gynecologists guidelines recommend that practitioners determine a woman’s BMI at the initial prenatal visit. The suggested weight gain is 25 to 35 pounds throughout your pregnancy. If you are considered underweight, your care provider expects you to gain more, and gain less if you start overweight. Weight gain is not linear. In the first trimester, you should only gain a few pounds. Then, you should experience a steady, gradual weight gain throughout your pregnancy. Even with these guidelines, most pregnant women are not gaining weight within the suggested ranges. One study that examined over 18,000 pregnancies found that just 25.8% of women gained weight within the recommended ranges, with 21.3% gaining less and 52.9% gaining above.

Monitoring Your Baby’s Health

In addition to checking your health, your care provider will check the baby’s health by listening to your baby’s heartbeat. In the first trimester, your provider detects your baby’s heartbeat with an ultrasound or Doppler. A Doppler is a handheld ultrasound device that amplifies the noises from your womb. Do not panic if your practitioner cannot pick up the sound of your baby’s heartbeat yet. Depending on your baby’s position and where your placenta is, it can be more challenging to hear a heartbeat early on.

Prenatal Tests

Your doctor or midwife will offer or suggest several prenatal tests during your pregnancy. You may feel like you are continually waiting for the result of some test to come back so you can be assured that your baby is healthy. Most tests are routine, and the highest probability is that your baby is healthy.

Screening vs. Diagnostic Tests

It is crucial to understand the difference between screening and diagnostic tests. A screening test gives you the likelihood of a condition and may signal that additional testing is needed. You would need a diagnostic test to diagnose anything. It can be devastating to get screening results back that show your baby is at a higher risk for anything. Please understand that you don’t know anything for sure until you have a diagnostic test.

Invasive vs. Noninvasive Tests

You can further classify tests as noninvasive or invasive. Noninvasive tests do not pose a risk to you or your baby. These typically use a urine or blood sample from you. If you are anxious about needles, you may not consider a test drawing your blood noninvasive. Let your doctor or midwife know if having blood drawn makes you uneasy. You can ask for someone with a lot of experience taking blood, so you do not have a first-day intern sticking you with a needle.

Routine Lab Tests During Prenatal Care

As part of your regular prenatal care, you will have several routine tests to monitor your health and identify potential risks to you or your baby. You can also expect a blood test at your first appointment. Blood is sent to a lab to determine blood type and the Rh factor. This sample will also be tested for glucose levels to monitor your risk for gestational diabetes, iron levels, and detect infections and genetic diseases. You can expect to have your blood pressure taken at each visit to monitor for signs of hypertension. You will give a urine sample at your first appointment, and may have additional urine tests throughout your care. Urine analysis or culture looks for glucose, proteins, ketones, and bacteria. Your doctor interprets the results to detect risks for infections of your urinary tract or kidneys, gestational diabetes, dehydration, and preeclampsia.

First Trimester Screen

The first-trimester screen is a noninvasive evaluation that combines a blood test for the mom with an ultrasound evaluation of the baby. This test is between 10 and 13 weeks, six days, and can identify risk for specific chromosomal abnormalities, including Trisomy-21 (Down syndrome) and Trisomy-18. The ultrasound portion of the test looks at the nuchal translucency. This fluid collects at the back of the baby’s neck. All babies have some fluid at the back of their necks. But many babies with Down syndrome have an increased amount.

A study published in the New England Journal of Medicine states the combined accuracy rate for the screen to detect chromosomal abnormalities is approximately 85%, with a false positive rate of 5%. Remembering that a positive result does not equate to having an abnormality is crucial. This is a screening test and can only indicate that you may want to discuss diagnostic testing with your care provider.

cfDNA (Cell-free DNA) Test

You can take the cell-free DNA test as early as nine weeks. This simple blood test looks for fragments of your baby’s DNA that freely float in your bloodstream. This test can detect many more chromosome abnormalities than the traditional screen tests, plus the sex of your baby and their Rh factor.

The accuracy of the cell-free DNA screening test is very high for common conditions like Down syndrome. Still, its effectiveness depends on the condition being tested and the characteristics of the population. In a higher-risk population, the positive predictive value is higher, meaning a positive result is more likely to be accurate. In lower-risk populations, the chance of a false positive increases.

ACOG and the Society for Maternal-Fetal Medicine recommend offering cfDNA screening to all pregnant patients, regardless of age or baseline risk. It is essential to have thorough counseling to understand what the test does and does not cover and how to interpret results.

For rare conditions like microdeletions, cfDNA tests perform much worse. A New York Times investigation found that positive results were incorrect about 85% of the time for the five most commonly tested microdeletions. If you receive a positive result for a rare condition, discuss it with your doctor, midwife, or genetic counselor to understand the accuracy and your options for follow-up diagnostic testing.

CVS (Chorionic Villus Sampling)

A chorionic villus sampling is a diagnostic test to determine if a baby has chromosome abnormalities like Down syndrome and genetic disorders like cystic fibrosis. The window for a CVS is between 10 and 13 weeks. A CVS involves removing some chorionic villi cells from the placenta at the point where it attaches to the uterine wall. There are two ways samples are collected. The most common method is transcervical, where an ultrasound guides a thin catheter through the cervix to your placenta, and the chorionic villi cells are gently suctioned into the catheter. The other method is a transabdominal approach, where an ultrasound guides a long, thin needle through the abdomen to your placenta. The level of accuracy is high, at 98-99%, but this test does not measure the severity of these disorders.

Miscarriage is the primary risk related to CVS. A systematic review and meta-analysis found the miscarriage rate to be 0.22%. There are other possible side effects for the mother following the procedure, including spotting, cramping, and pain at the puncture point. 

First Trimester Vaccines

Vaccines are a very controversial and complex topic. The choice to get vaccinated is a decision you should make with your doctor or midwife. If you have questions or concerns about any vaccine, please bring them up with your care provider. Vaccines should be given with informed consent, which means you are aware of all the risks and benefits, and you can opt in or opt out. 

The American College of Obstetricians and Gynecologists recommends four vaccines during pregnancy. These vaccines help protect you and allow you to pass antibodies to your baby before birth. COVID-19 and influenza vaccines may be available as early as the first trimester. Some expecting parents and care providers may choose to avoid vaccines during the first trimester because this period is considered the most sensitive for development.

ACOG states that vaccination for COVID-19 may occur in any trimester, and emphasis should be on vaccine receipt as soon as possible to maximize maternal and fetal health. The timing of the flu vaccine aligns with the flu season, which runs from October through May in the United States. ACOG states that if you are pregnant, it is best to get the vaccine early in the flu season, as soon as it is available, and you can get the shot at any time during your pregnancy.

You have options regarding the timing of when you get a vaccine. In the case of COVID-19 and influenza, you also have more than one option for the vaccine you get. These resources have more in-depth information on these vaccines and your options:

• COVID-19 Vaccine in Pregnancy: Risks, Benefits, and Research
• Flu Vaccine in Pregnancy: Evidence-Based Risks and Benefits

To-Do Items for the First Trimester

The first trimester is a significant adjustment period. You can do some simple things to get your pregnancy off to a healthy start.

Take Care of Your Health

The first thing you should do in your first trimester is take care of your health. Do not stress out if you are not the healthiest person right now. Many women find out they are pregnant before implementing a healthier lifestyle, and their babies are perfectly healthy. It is never too late, and today is a fantastic day to start.

The first trimester is a good time to evaluate your diet. Your goal should be to eat mostly healthy, whole foods. Some episodes examine the evidence on specific aspects of diet, like fish, meat, sugar, natural and artificial sweeteners, plant-based diets, and organic foods. It is also critical to drink adequate water and stay hydrated. You should take a high-quality prenatal vitamin, not just a multivitamin. Prenatal vitamins contain more folic acid and iron than standard multivitamins, which is critical for your baby’s growth and development.

Regular exercise during pregnancy can decrease your risk of complications like gestational diabetes, preeclampsia, and cesarean birth, promote healthy weight gain, and ease many common pregnancy symptoms. Whether you are an athlete or are just starting to incorporate exercise, almost any activity can be modified so that you can feel empowered to exercise during your pregnancy. There are more in-depth episodes on specific exercises, including cardio, strength training, and yoga.

The growing body of research on sleep demonstrates the absolute necessity of sleep for every biological function. This includes learning, memory, brain function, mental health, appetite regulation, immune system function, metabolic function, gut microbiome health, and cardiovascular health. It is well-established in the scientific literature that sleep is critical for all aspects of health, especially during pregnancy. The good news is you can take many evidence-based and straightforward steps to improve the quantity and quality of your sleep.

Visit the Dentist

Several common oral health conditions can occur in pregnancy. Approximately 40% of pregnant women have some form of periodontal disease. The American College of Obstetricians and Gynecologists recommends that you see a dentist during pregnancy and that cleanings and x-rays are safe. Make dental care a priority and schedule an appointment.

Exploring Your Birth Options

You have options when it comes to everything in your pregnancy. Your primary doctor or midwife and where you plan to give birth greatly influence your choices. The first trimester is a good time to start exploring what type of provider you want to work with and where you want to give birth. The majority of births in the U.S. take place in a hospital. If you are open to it, check out your options to have a home birth or visit a birth center. Even if you want an unmedicated birth, you can have a natural birth in the hospital.

Understand Your Health Insurance

In the United States, the average cost of vaginal birth is nearly $10,000, and the average price for a cesarean section is close to $14,000. There are tools and strategies you can use to save money on your medical bills. Insurance can help cover the cost of prenatal care and birth. Tax-advantaged accounts like flexible spending or health savings accounts can save you money on the expenses you have to pay.

If you have health insurance, ensure you understand how your insurance works and what is covered for your prenatal care and birth. If you feel like you are not in a financial position to obtain insurance, there are resources like Medicaid or subsidies. The hospital or birth center where you plan to have your baby may offer reduced rates based on income or other discounts, and you may be able to negotiate a payment plan. Even if money is tight, you have options. See this episode to learn about the cost of birth, how your insurance works, how to minimize costs, and tips on getting coverage assistance.

Decide When to Announce Your Pregnancy

Many expecting parents wait until the 12-week mark to announce their pregnancy. The main reason is that the risk of miscarriage drops significantly at the end of the first trimester. It is common to have some anxiety about the possibility of miscarrying. Especially early on, you may have some signs or symptoms of pregnancy, but you don’t look pregnant and can’t feel your baby moving or kicking. Talk about announcing your pregnancy with your partner and get on the same page about when to share the news.

Your Partner’s Role in the First Trimester

Some mothers have babies without the luxury of a partner. If the two of you can navigate this together, you are fortunate. The entire process of having and raising a baby is exponentially more difficult alone. If you don’t have a romantic partner or a co-parent, I encourage you to lean on friends and family so you are not going through this phase of your life without support.

As soon as there is a positive pregnancy test, there are many things partners and dads can do to support mom. Partners can support eating healthy, whole foods by cooking meals at home or grabbing healthier options when eating out. Your partner can let you sleep in or encourage you to go to bed earlier if you are tired. If you need support to be active, an invitation from your partner to go on a walk or encourage you to do something active together can be helpful. It can be even more challenging if you have difficulty with healthy habits and your partner is not supportive and encouraging. 

All kinds of symptoms can pop up during pregnancy. You can mitigate some of these symptoms with remedies. Unfortunately, some conditions are out of your control and will persist until your baby is born. Your partner may not be experiencing the same things you are, but they can empathize with you. Sometimes, it is nice to know that someone is by your side, even if they cannot relate and don’t have any solutions.

If your partner can attend your doctor or midwife appointments, please encourage them to accompany you. You can expect to have around 14 appointments throughout your entire pregnancy. Your partner should prioritize being there in person or virtually for all of them. Or at least as many as they can. This allows your partner to be included, have input in major medical decisions, ask questions, and hear everything firsthand. If any complications come up throughout prenatal care or you get some unfavorable test results back, those appointments can be challenging to go through alone. Having your partner by your side can be a fantastic source of support. One of the more essential appointments for your partner to attend is the first appointment, when a doctor or midwife confirms the pregnancy and sets expectations. 

Make the Most of Your First Trimester

Your first trimester is the shortest, especially when you consider you don’t even get pregnant until week three and probably do not know you are pregnant until week four or five. Pregnancy can come with many uncomfortable symptoms and a rollercoaster of emotions. If you struggle with conditions like morning sickness, hang in there and know this will improve. While the amount of information to consume about pregnancy and birth can be overwhelming, you have a lot of time before your baby will be here. Do not forget to appreciate everything your body is going through to build a human.

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