Is it a cold? The flu? Or is it COVID-19? Either way, it is miserable.

It is Friday afternoon. You are pregnant, or actively planning, and you wake up with a scratchy throat, pressure in your nose and forehead, and runny nose. You think you have a cold… or is it the flu or COVID-19? You have left a message with your healthcare provider to ask them about what to do and what medication you can take. You are worried about taking the wrong medication. As the hours pass, you think it is unlikely that you will be able to get in touch with them before the end of the workday. Now, you are worried about going into the weekend without medication.

What to do? First, try to figure out if it is a cold, flu, or COVID-19. Some healthcare providers may share instructions for this situation and/or give their pregnant patients a list of medications that they approve for common medical conditions. When this list is not provided, many pregnant women contact MotherToBaby specialists for help. Although MotherToBaby specialists cannot make specific medication recommendations, we can provide information on most medications based on the studies and how the drugs work.

Is It a Cold?

A cold is caused by one of more than 200 viruses. Colds can spread easily from person to person. Symptoms can include sore throat, runny or stuffy nose, sneezing and coughing, headache, and muscle aches. For healthy pregnant women, an infection with a cold is not associated with a higher risk to her or her developing baby. There is no testing for a cold. Generally, colds are treated with over-the-counter medications.

Is it the Flu?

Influenza, often called “the flu,” is an illness caused by a virus. Flu symptoms include fever (typically between 100°F to 104°F), chills, cough, sore throat, body aches, and tiredness. Pregnant women and their pregnancy are at higher risk from flu. Testing for flu is available in the doctor’s office and at some pharmacies. Antiviral medications are recommended for pregnant women even if the testing has not been completed due to the risks from flu.

Is it COVID-19?

COVID-19 is caused by the SARS-CoV-2 (virus). The symptoms of flu and COVID-19 are similar. Symptoms include fever, cough, shortness of breath, sore throat, body aches, headache and change of taste or smell. Some people may have symptoms that last a short time and others may get very sick. Pregnant women and their pregnancy are at higher risk from COVID-19 infection. Testing for COVID-19 is available over the counter. Medication is recommended by health organizations for pregnant women with COVID-19.

Fever

In adults, a fever is a temperature of 100.4°F (38°C) or higher. Most healthcare providers recommend acetaminophen to treat fever, headache, and body pain in pregnancy. Studies on acetaminophen use during pregnancy have not shown a higher risk to the developing baby when it is used as directed for a short time.

A high fever that is untreated in pregnancy increases the chance of birth defects. A temperature of 101°F that lasts for over 24 hours early in pregnancy may increase the risk for a birth defect of the spine. You can read more about fever at https://mothertobaby.org/fact-sheets/hyperthermia-pregnancy/.

Over the Counter and Self-care Treatments

Pharmacies have rows of cough and cold products. In pregnancy, it is best to take an alcohol-free medication that contains only those ingredients that address the specific symptoms. For example, if the only symptom is body aches, taking a multi-symptom medication for congestion, cough and body aches would mean unnecessarily exposing yourself and the developing baby to medications.

Below we review some over-the-counter cold treatments and self-care treatments. The options below do not cover all treatments and should not be considered a recommendation. Ideally, it is best to always discuss your symptoms with your healthcare provider, because they know you best and can take into account any unique health issues that you may have.

Medication for Cough

Because many cough syrups can contain up to 10% alcohol, it is important to select an alcohol-free cough syrup. Cough syrups may also contain ingredients for stuffy nose or pain. If the only issue is a cough, taking the medication with the least ingredients is preferred to minimize the exposure to the pregnancy.

Cough drops and throat lozenges can contain flavorings such as honey, menthol, or anesthetics to numb the throat. There is no warning about using these during pregnancy for cough or a sore throat.

Vitamin C and other vitamins are taken during a cold or for cold prevention. During pregnancy, it is recommended to limit vitamins to those in the prenatal category unless recommended by the healthcare provider. Vitamins, like medications, cross the placenta and expose the developing baby which does not have a need for higher doses and in some cases, could be harmful.

Tea and Honey

Honey and warm tea may be helpful in relieving a sore throat caused by coughing and may thin mucus so that the cough is more productive. There is no warning about eating honey in tea, toast, or any other food during pregnancy. Herbal tea does not have caffeine and if taken as a beverage, there is no warning. Black tea, green tea, and white tea may have caffeine. If taking tea with caffeine, it is important to read the label to learn about the amount of caffeine per cup. Pregnant women can have up to 200 mg of caffeine per day from all sources combined. If drinking decaf tea, there is no warning to pregnant women.

Medications for Nasal Congestion

A stuffy nose can cause painful sinuses and make it less enjoyable to eat and hard to sleep. Over-the-counter nasal decongestant choices fall into two categories: oral (pills by mouth) or nasal spray. Some oral decongestants are pseudoephedrine and phenylephrine. Nasal sprays may contain phenylephrine, oxymetazoline, or steroid medications. Taking an oral decongestant means that your developing baby will be exposed to the medication. Nasal sprays reduce the chance of exposure to your baby, depending on the frequency of use and dose. Always read the labels and take them as directed.

Nasal Congestion: Non-medication Options

Nasal irrigation (bulb syringe, squeeze bottle, or neti pot): Studies of nasal irrigation have not shown a proven benefit on the duration or severity of colds. However, some people who have used nasal irrigation have reported feeling better. For pregnant women, the most reassuring part is that it uses only water and saline, so there is no medication involved and no exposure to the pregnancy. It is important to use only previously boiled, distilled, or sterile water to irrigate; and to keep nasal irrigation equipment clean and sterilized to avoid the risk of infection.

Shower tablets/vaporizers: Shower vapor tablets have become popular because they might help clear stuffy noses for a short time. These tablets are placed on the shower floor and as the warm water reaches the tablet, it dissolves and makes a steam with a vaporizer-like effect. Most shower tablets ingredients include sodium carbonate, sodium bicarbonate (baking soda), and essential oils (such as peppermint, rosemary, eucalyptus, and lavender). There are no studies on the use of shower tablets during pregnancy, but essential oils are used in many candles, lotions, and other home products, so exposure to these oils is common. With use as directed, it is not expected that the ingredients in shower tablets would increase the chance for problems during pregnancy.

Humidifiers: Humidifiers are used to add moisture to the air and provide relief from sinus pressure, dry skin, and throat. They use only water so there is no medication exposure. It is important to keep humidifiers clean to avoid the risk of putting mold and bacteria into the air, which could then cause allergies.

Nasal strips: Nasal strips are marketed to people who have a hard time sleeping due to snoring, but they also claim to help with congestion from colds. Although there are no studies that show these products help with colds, there is some evidence that they may help with snoring by spreading the nose and widening the air passage. Nasal strips do not contain medication, so there is no concern about their use during pregnancy.

Electric Blankets and Heating Pads: Electric blankets are sometimes used by people with body chills from having the flu or a cold. Electric blankets produce heat that varies from 86°F (30°C) to 122°F (50°C), which can be comforting. However, there is some concern about the heat from use of electric blankets in early pregnancy, raising body temperature and increasing the risk of birth defects of the spine. However, the studies on electric blanket use during pregnancy have some problems and not all have shown problems in pregnancy. As the studies are unclear, pregnant women may want to avoid the higher heat for peace of mind.

Remedies to Avoid

Vitamin C and zinc: When you feel a cold coming on, you could be tempted to reach for vitamin C and zinc. This is not recommended during pregnancy. First, there is not enough evidence that vitamin C or zinc help in preventing or treating colds. Second, the doses of vitamin C and zinc in supplements for colds are higher than recommended doses for pregnant women. The recommended vitamin C dose is 80 mg for pregnant teens and 85 mg per day for pregnant adults. The recommended dose for zinc is 12 mg for pregnant teens and 11 mg per day for pregnant adults. If you are taking prenatal vitamins, it is likely that they contain the vitamin C and zinc that you need for the day.

Non-steroidal anti-inflammatory drugs (NSAIDs): For most healthy pregnant women, over-the-counter pain relievers such as ibuprofen, naproxen, and aspirin are generally not recommended during pregnancy. NSAIDs are associated with a risk for premature closure of the ductus arteriosus (a heart and lung condition) in the baby if the medication is used at higher doses in the second half of pregnancy. Although low dose aspirin is sometimes recommended in pregnancy under a doctor’s supervision to treat or prevent specific medical conditions, regular strength aspirin and other NSAIDs are not typically recommended for treating pain or fever in pregnancy.

Herbal products: Many herbal supplements marketed for treating colds and flu have not been studied in pregnancy, so the possible risks are not known. In addition, the benefits of using herbal supplements are not always proven. For example, echinacea has been promoted as a cold remedy, but a review of over 24 studies with over 4,000 participants did not find that it shortened the number of days for a cold compared to people who did not take echinacea.

Prevention

Vaccination is key and the best tool that we have for preventing flu and COVID-19 or reducing the severity of the symptoms if you do get infected. Studies involving many thousands of pregnant women have not shown a higher risk of birth defects or complications. MotherToBaby has fact sheets with information on both the flu vaccine and COVID-19 vaccine.

References:

Botto LD, Lynberg MC, Erickson JD. (2001). Congenital heart defects, maternal febrile illness, and multivitamin use: A population-based study. Epidemiology. 12:485-90.

Centers for Disease Control and Prevention. (2025). Treating Flu with Antiviral Drugs. Retrieved from https://www.cdc.gov/flu/treatment/antiviral-drugs.html

Centers for Disease Control and Prevention, NIOSH Science Blog, April 9, 2020. Respiratory Protection During Outbreaks. Retrieved from https://blogs.cdc.gov/niosh-science-blog/2020/04/09/masks-v-respirators/

Chambers CD, Johnson KA, Felix RJ, Dick LM, Jones KL. (1997). Hyperthermia in pregnancy: a prospective cohort study. Teratology. 55:45.

Hubner, N-O., Hubner C., Wodny M., Kampf G., Kramer A. (2010). Effectiveness of alcohol-based hand disinfectants in a public administration: Impact on health and work performance related to acute respiratory symptoms and diarrhea. BMC Infectious Diseases. Retrieved from http://www.biomedcentral.com/1471-2334/10/250

Karsch-Völk, M., Barrett B., Kiefer D., et al. (2014). Echinacea for preventing and treating the common cold. The Cochrane Database of Systematic Reviews. 2014(2):CD000530.

At some point, most of us have been told to “eat healthy.” Sounds simple enough, right? But what that means can look different from person to person. For some, it’s about cutting back on junk food and adding more fruits, vegetables, and whole grains. For others, it might mean watching sodium intake, choosing foods that support heart health, or managing cholesterol levels.

No matter your health history, eating well is something we’re all encouraged to do, especially during pregnancy and while breastfeeding, when your body is supporting both you and your baby.

But if you’re living with an eating disorder, pregnancy or breastfeeding can add extra layers of complexity. It’s not just about what to eat anymore: questions about how much to eat, how often to eat, and how to manage hunger cues or body changes can feel overwhelming. These challenges are real, and they deserve thoughtful, compassionate support.

A few years ago, I received a call from a woman named “Alice.” She called MotherToBaby because she was taking medication for high blood pressure and wanted to know if it would affect her pregnancy. After some discussion, she told me her blood pressure was high because she was quickly gaining a lot of weight from binge eating. She said she had been binge eating for a long time and did not know how to stop. She was worried about how this would affect not only her health, but also that of her baby. When I asked what her healthcare provider suggested, she told me she was afraid to talk to her midwife about it.

What is an eating disorder?

An eating disorder is a mental health disorder that results in serious disturbances of eating behavior. There are several different eating disorders, including anorexia nervosa, bulimia nervosa, binge eating disorder, and pica. Each disorder has its own symptoms and effects. In the United States, 9% (28 million) of people will have an eating disorder in their lifetime.

• Anorexia nervosa –severely restricting the amount of food eaten, resulting in very low body weight.
• Bulimia nervosa – binge eating (eating large amounts of food in a short time and feeling loss of control overeating) and then purging (vomiting, not eating, over-exercising, misusing laxatives or diuretics).
• Binge-eating disorder- binge eating without purging.
• Pica – a craving for and eating of substances without any nutritional value (such as ice, clay, paper, or dirt) for at least one month. The number of women affected by pica is unknown, but it is much more common in pregnant women than in non-pregnant women; it is also more common in developing countries than in the US.

Eating disorders can be hard to spot under any circumstances, and that can be even more true during pregnancy and after a baby is born. So much focus is placed on weight changes, appetite shifts, and body changes during this time that warning signs can easily be overlooked or explained away as “just part of pregnancy.” Also, not all healthcare providers receive specialized training in recognizing eating disorders, especially in pregnant or postpartum patients. That means symptoms can sometimes go unnoticed, even during regular prenatal or postpartum visits.

There’s also a lot of stigma surrounding eating disorders. Some women may feel embarrassed, ashamed, or afraid to speak up about their struggles. Others might worry about being judged or not being taken seriously. All of that can make it incredibly difficult to admit that something isn’t okay.

Can eating disorders affect my pregnancy?

A healthy, well-balanced diet during pregnancy is important for a fetus to grow and develop. It can also help to minimize some pregnancy symptoms such as nausea and constipation. Certain eating-disorder behaviors can cause issues during pregnancy and may require hospitalization or other specialized care. For example:

• Not eating and/or calorie restriction can cause low energy and nutritional gaps in the mother and low birth weight for the baby.
• Vomiting can cause dehydration, electrolyte imbalances, sore throat, stomach pain, tooth damage, gum disease, and ruptured esophagus in the mother.
• Using laxatives/diuretics can cause dehydration, electrolyte imbalances, laxative dependency, and organ damage in the mother.
• Over-exercising can lead to fatigue, muscle pain/soreness, dehydration, and overheating in the mother.
• Binge eating can lead to excessive weight gain, gestational diabetes, high blood pressure (and other complications) in the mother, and large birth weight for the baby.
• Eating non-food substances (pica) can interfere with nutrient absorption and may contain dangerous substances that could be harmful to mom or baby. See our fact sheets on toxoplasmosis and lead.
• Mental health issues, such as depression or anxiety, go hand in hand with eating disorders. Learn more about how mental health disorders can affect pregnancy and breastfeeding.

What about breastfeeding?

Getting sufficient “high quality” calories is important for everyone. During breastfeeding, the body needs energy to make enough milk, and not getting enough calories can make it harder to do. For pica, non-food items may contain something potentially harmful to the baby, such as lead.

Studies have suggested that women with eating disorders might be more likely to stop breastfeeding within the first 6 months. However, it is possible to successfully breastfeed with an eating disorder, even if they are taking medications. The key is finding support, which you can get from healthcare providers (doctors, nurses, lactation consultants), family, friends, and support groups (online, over-the-phone, and in person).

Help is Available

If you have been diagnosed with an eating disorder, or think you may have one, talk with your healthcare provider. You are not alone. There are resources available to help you and your baby be as healthy as you can be.

Talk to your healthcare provider to discuss how many calories per day are right for you. There are many resources available to help educate people about good food choices, such as the Americal College of Obstetrics and Gynecology’s Frequently Asked Questions on healthy eating during pregnancy. The National Institutes of Health has information on which foods/drinks to limit/avoid, the appropriate amount of weight to gain, and the recommended amount of exercise.  

And finally…

So, what happened to Alice? She called several times throughout her pregnancy and while breastfeeding. After our first conversation, she told her midwife everything. Alice did develop gestational diabetes, but under the care of her midwife, nutritionist and counselor, she was able to stop gaining weight and get her blood sugar and blood pressure under control. She gave birth to a healthy baby and continued to work with her team during breastfeeding. She thanked me for suggesting she ask for help and said she was closer to finding something we all are looking for – balance.

Originally authored by Chris Stallman Aug. 2, 2018, edited by Bridget Maloney, Certified Genetic Counselor at MotherToBaby Arizona, on February 17, 2026.

By Beth Kiernan, MPH, Interviewer & Teratogen Information Specialist, MotherToBaby

Kristin called MotherToBaby one afternoon saying, “I just took a home pregnancy test and it’s positive.” Kristin sounded beyond worried. “I’ve been taking a medication for ADHD since I was eight years old, and when I searched the internet it said it was harmful and that I should stop taking it before getting pregnant.” Kristin hadn’t planned on getting pregnant. Now, not only was she terrified she had hurt her unborn child, but she also found it impossible to think about stopping the medication for a very good reason: “I am a nurse in the Cardiac Intensive Care Unit at a hospital – staying focused is critical to the lives of my patients.”

Kristin isn’t alone in her concerns.
This is one of the most frequent topics asked about by people who contact MotherToBaby, which isn’t really surprising. About 1.4 million people in the U.S. have been diagnosed with Attention Deficit Disorder (ADD) or Attention Deficit Hyperactivity Disorder (ADHD). Since nearly half of pregnancies in the U.S. are unplanned, her situation isn’t uncommon.

ADD and ADHD are chronic conditions often diagnosed in childhood. They cannot be cured, but can be treated with behavioral counseling/coaching, medication, or both. If you or someone you know are affected by ADD/ADHD, you know that there are some classic things that can be challenging, including difficulty staying organized at home and at school or work, problems with sleep, being distracted, acting without thinking things through, having trouble behaving appropriately, struggling to finish tasks, having a short temper, talking too much, feeling anxious or restless or bored, and sometimes addictive tendencies.

About 60%-80% of kids diagnosed with ADD/ADHD will need to take their medications into adulthood, since it often helps them in daily life. But what about when a woman with ADD/ADHD gets pregnant? This was Kristin’s concern, and Dr. Google (searching the internet for medication advice in pregnancy) isn’t the recommended solution! Thankfully for Kristin, this is our specialty here at MotherToBaby. We talk with women about all their medication choices and concerns, referring to key research to educate them. This gives them the information they need to discuss their medication choices with their healthcare providers.

Kristin was taking Ritalin.
Ritalin is a stimulant medication also called methylphenidate. Kristin’s concern reflects the fact that Ritalin is grouped with other stimulants like amphetamines and methamphetamine, so it can be hard to untangle the research when everything is lumped together in discussions of pregnancy. Obviously, drugs used in an addictive way like “meth” or “speed” aren’t advised in pregnancy because research has shown negative effects, like pregnancy complications and postnatal problems in behavior, emotions, memory, attention, and growth. However, taking a prescribed daily dose of methylphenidate or other ADD/ADHD medications during pregnancy hasn’t shown increased risks for having a baby with a birth defect. Nor have we seen an increased risk for pregnancy complications like preterm delivery or low birth weight. Plus, babies exposed to prescription levels of methylphenidate in utero that were studied up to a year of age have had normal development.

I told Kristin that, for people like her with ADD/ADHD, methylphenidate can really promote success at work, in school, and in getting along with other people. Going off this medication can create problems, so it’s good to know that the data we have on its effects in pregnancy is reassuring.

Other side effects of ADD/ADHD medications on a pregnancy.
I also shared with Kristin some pregnancy-specific information: sometimes people who take methylphenidate feel less hungry, and when combined with pregnancy this may lead to weight loss. Similarly, changes in the body while pregnant can mean that the prescribed daily dose level may need to be periodically changed during pregnancy to adequately treat ADD/ADHD. Lastly, stimulants can affect heart rate and blood pressure. I told Kristin that if she had any of these issues while pregnant, she should call her healthcare provider. And I added that if she still felt nervous about taking her medication, that perhaps her doctors could help her find other ways to manage her ADHD.

Still concerned, Kristin asked if her baby might be born addicted to Ritalin. I explained to her that sometimes babies exposed to stimulants right up until birth have shown symptoms of withdrawal after delivery. When babies have this condition, they may have trouble eating, may sleep too little or too much, may have very floppy or stiff muscles, or be jittery. These usually disappear within 1-2 weeks and there are no lasting effects. Babies who have more severe symptoms may have to stay in the hospital a little longer to be treated. However, we wouldn’t expect this level of withdrawal to occur with regular use of methylphenidate that is taken as prescribed by a doctor. In addition, it’s hard to predict if withdrawal symptoms will even happen. It’s seen more often when women take opioids and other medications for mental illness and epilepsy. With daily doses of methylphenidate, it’s possible that her baby could have mild symptoms or no symptoms, even if Kristin needed to take it until delivery.

What about breastfeeding?
Finally, Kristin said that, while she hadn’t planned to be pregnant, she was excited about it, and hoped to breastfeed too since she’d heard that was best for her baby. She asked if she could continue to take her Ritalin and nurse her baby. I told her that small amounts of methylphenidate have been found in studies on breastmilk, but that the levels are so low that it wouldn’t be expected to cause problems. Normal sleeping and feeding have been reported in the exposed infants. I suggested she also speak with her pediatrician about it once she found one in her insurance network.

In the end, Kristin told me that she felt very relieved to get a full understanding of her situation, and to be able to more accurately understand the possible risks to her pregnancy versus the benefits for her of staying on her medication. Now she can “focus” on preparing for the next chapter in her life: impending motherhood!

Beth Kiernan, MPH, is a Teratogen Information Specialist with MotherToBaby Pregnancy Studies, a non-profit that conducts observational research about exposures in pregnancy and provides information to healthcare providers and the general public on medications and more during pregnancy and breastfeeding. She is based at the University of California, San Diego, and is a married mother of four children.

About MotherToBaby

MotherToBaby is a service of the Organization of Teratology Information Specialists (OTIS), suggested resources by many agencies including the Centers for Disease Control and Prevention (CDC). If you have questions about exposures, like medications to treat ADD/ADHD, during pregnancy and breastfeeding, please call MotherToBaby toll-FREE at 866-626-6847 or try out MotherToBaby’s new text information service by texting questions to (855) 999-3525. You can also visit MotherToBaby.org to browse a library of fact sheets about dozens of viruses, medications, vaccines, alcohol, diseases, or other exposures during pregnancy and breastfeeding or connect with all of our resources by downloading the new MotherToBaby free app, available on Android and iOS markets.

“Sometimes I forget I am adopted,” exclaims my amazing son as he grabs his backpack to head off to college. I had just let him know that his birthday this year falls on National Adoption Day. “So cool! We will need to do something special this year on my birthday, to celebrate both my birthday and my adoption! See ya, mom!” To Shaun, adoption is as easy as one, two, three, and just a part of everyday life. As anyone who’s been through adoption knows, this is simply not the case much of the time. While adoption helped us complete our family, the process can be exciting, thrilling and scary all at the same time! When another woman is carrying the baby that will become your child, you worry. Was she drinking alcohol? Taking a pain killer? What if she was using illegal drugs?! It can literally lead to countless anxious days and sleepless nights. I understand these concerns as I shared the same worries.

National Adoption Day, started in the United States in 1999, is celebrated each year on the Saturday before Thanksgiving. This year it happens to fall on Shaun’s birthday and reminds me of when we adopted him, many years ago. That time in my life was so powerful, but it was easier for me than it is for others as I was part of MotherToBaby and already knew where to find the answers to my pregnancy exposure questions.

My adoption journey has helped shape who I am today – a genetic counselor and a teratogen information expert who specializes in understanding exposures that can cause birth defects. The non-profit I work for provides this crucial service all across North America and I’m proud that my journey has brought me into a position to ease the minds of other prospective parents starting down the wonderful path of adoption. It reminds me of Austin and Drew, a prospective adoptive couple whom I helped in their adoption journey, “My partner and I did a lot of research as we started exploring adoption. After we started working with an agency, there were lots of questions about prenatal exposures, birth parent medical histories, etc. A lot of the information we found on these topics seemed to be contradictory and some of it was downright scary.”  My job allows me to be on the other end of the line talking to this couple, and others like them, helping fill out intake forms and providing evidence-based answers to some of their questions. “Luckily for us, our adoption agency suggested we reach out to Lori. After our conversation we felt much more at ease, and we felt like we had the information we needed to make informed decisions.”

My own journey has come full circle, utilizing my training to help those going through what I went through years ago. MotherToBaby specialists are here to help you too! As Rory Hall, Executive Director of Adoption Advocates, states, “couples approach the adoption process with so many myths about prenatal exposures and health concerns that might affect a baby. MotherToBaby experts help them approach adoption with relevant, scientific backed information so they can make informed decisions about the children they are hoping to adopt.”

Just before Shaun shuts the door to drive to school, he pauses. Sometimes wise beyond his years, he turns and says, “Mom, adoption is so wonderful because your birth parents gave you up so you could have a better life. Love you!” And just like that, the anxiety, and struggle during the adoption process go back to their place of being a very distant memory. #WorthIt.

More about National Adoption Day

National Adoption Day has been celebrated across the United States since 1999, helping to raise the awareness of the more than 100,000 children who are in foster care each year in the U.S. waiting for permanent families. For more information, see www.nationaladoptionday.org. And when you are going through your adoption journey, and have questions about exposures during pregnancy, contact an expert at MotherToBaby. You can reach us by phone at 866-626-6847 or by text at 855-999-3525.

Originally published 11/3/16, Updated 8/31/2025

Having worked as a Teratogen Information Specialist at MotherToBaby for close to 10 years, I have become well versed in the different exposures people commonly ask about. Allergy medications in the spring, sunscreen and bug spray in the summer, and cough and cold medications all winter long. So, when I logged onto our live chat service at mothertobaby.org on a Tuesday morning, I was surprised to see a question that doesn’t come up very often. Natalie, pregnant with her first child, asked: “I’m 24 weeks pregnant and my midwife says I need a RhoGAM shot at my next appointment. What could happen to the baby if I do not get this shot?”

Blood Type Basics

Blood type is hereditary, which means it is passed down from your parents. There are 8 common blood types: A+, A-, B+, B-, O+, O-, AB+, and AB-. If your blood type ends in a minus sign (like A- or O-), you are Rh negative. If it ends in a plus sign (like A+ or B+), you are Rh positive. Most people in the United States are Rh positive, but about 15 out of every 100 people (15%) are Rh negative. A blood test early in pregnancy will tell you your blood type.

What is Rh Incompatibility?

During pregnancy, if a woman who is Rh negative is pregnant with a fetus that is Rh positive, a condition called Rh incompatibility can happen. Rh incompatibility becomes an issue if any of the Rh positive red blood cells from the fetus get into the mom’s Rh negative bloodstream. This is most likely to occur during a miscarriage, certain prenatal tests (like amniocentesis or CVS), a fall, labor and delivery, or if the placenta separates from the wall of the uterus. When this happens, the mom’s immune system might treat the fetus’ red blood cells as something that shouldn’t be in the body (like an infection) and start making antibodies against them. In most cases, these antibodies will not negatively affect the current pregnancy, but they might affect future pregnancies.

When Antibodies Attack

Once the mom’s body makes anti-Rh antibodies, they stay in her system for life. If she becomes pregnant again with another Rh positive fetus, the antibodies can cross the placenta and attack the fetus’ red blood cells. This can lead to a condition called hemolytic disease of the fetus and newborn (HDFN). Without enough red blood cells, the fetus cannot carry enough oxygen during development and complications such as jaundice (yellowing of skin and eyes), hemolytic anemic (low red blood cell count), hydrops fetalis (fluid buildup in the baby), high bilirubin levels, kernicterus (brain damage from the bilirubin), and even death can occur.

RhoGAM to the Rescue

Fortunately, there is a way to lower the chance of HDFN: The RhoGAM shot. Typically given around 28 weeks of pregnancy (and again within 72 hours of birth if the baby is confirmed to be Rh positive), RhoGAM is an antibody that helps stop the Rh negative mom from making antibodies that could attack a future fetus’ red blood cells and cause HDFN. Before RhoGAM was available, thousands of babies died from the condition every year. Nowadays, the chance of HDFN is less than 0.1% when the shot is given, making RhoGAM a remarkable intervention.

Protecting Your Future Babies

After sharing this information with Natalie, I summarized our conversation with a quick recap. Since she is Rh negative, her midwife was recommending a RhoGAM shot at 28 weeks to prevent the development of antibodies that could negatively affect a future pregnancy. An increased risk for miscarriage or birth defects is not expected since the shot is given later in pregnancy and Natalie is past the “critical period” for those outcomes to occur. Pregnancy complications, like preterm delivery and low birth weight, have not been reported in the available studies examining the use of RhoGAM in pregnancy. Natalie felt reassured after receiving this information and decided to proceed with the RhoGAM shot at her next midwife appointment.

If you have questions about the RhoGAM shot or any other exposures in pregnancy, please feel free to reach out to MotherToBaby by phone, chat, text, or email to receive evidence-based information that can help you make an informed decision.

References:

• American Red Cross. Facts About Blood and Blood Types. American Red Cross. https://www.redcrossblood.org/donate-blood/blood-types.html. Published 2025. Accessed April 29, 2025.

• Bowman J. Thirty-five years of Rh prophylaxis. Transfusion. 2003;43(12):1661-1666. doi:10.1111/j.0041-1132.2003.00632.x

• Hematology: Vaccinating the Rh-Negative. Time Magazine. June 21, 1968. https://time.com/archive/6636313/hematology-vaccinating-the-rh-negative/. Accessed April 30, 2025.

• The American College of Obstetricians and Gynecologists. The Rh Factor: How It Can Affect Your Pregnancy. https://www.acog.org/womens-health/faqs/the-rh-factor-how-it-can-affect-your-pregnancy. Published 2024. Accessed April 29, 2025.

• Yoham AL, Casadesus D. Rho(D) Immune Globulin. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2025 Jan. Updated May 22, 2023. https://www.ncbi.nlm.nih.gov/books/NBK557884/. Accessed April 28, 2025.