Common Infections During Pregnancy
When you are pregnant, your body works a little differently. Your immune system adjusts itself to protect your baby — which means some infections need a little more attention than they would outside of pregnancy. This is not scary. This is just good information to have.
Why Infections Matter More in Pregnancy
Here is something most women are not told clearly enough.
When you are pregnant, your immune system deliberately dials itself down a little. Not because something is wrong but because your body needs to accept your baby, who carries DNA that is half from someone else. If your immune system stayed at full strength, it might treat your baby like a foreign object and attack it.
So your body makes a compromise. It softens. It adjusts. And as a result , some infections that would give you a few uncomfortable days normally can hit a little harder in pregnancy. And some of them can cross the placenta and affect your baby too.
This does not mean you will get sick. Most women go through their entire pregnancy without any significant infection. But knowing which ones to watch for, how to avoid them, and what to do if you think something is wrong , that is the kind of knowledge that protects two lives at once.
Let's go through them one by one. Simply. Clearly. No medical overwhelm.
1. Urine Infections (UTIs)
A urine infection , also called a UTI or urinary tract infection , is when bacteria get into your bladder and cause an infection. It is one of the most common infections in pregnancy. In fact it affects up to 1 in 10 pregnant women.
Why does pregnancy make it more likely? Two reasons. First, pregnancy hormones relax the muscles in your urinary tract. Second, your growing uterus puts pressure on your bladder. Both of these make it easier for bacteria to travel up and cause an infection.
Outside of pregnancy, a UTI is annoying but usually not dangerous. In pregnancy, if a urine infection is not treated it can travel up to your kidneys and a kidney infection can trigger early labour. This is serious. This is why even a mild UTI in pregnancy always needs treatment with antibiotics.
There is also something called a silent UTI ,where bacteria are in your urine and causing infection, but you feel absolutely no symptoms at all. This is why your doctor tests your urine at every single prenatal appointment. They are checking even when you feel completely fine.
- · Burning or stinging when you urinate
- · Needing to run to the bathroom urgently but very little coming out
- · Urine that looks cloudy, dark, or smells stronger than usual
- · A dull ache or pressure in your lower belly
- · Sometimes absolutely nothing at all
- · You have a fever above 38°C along with back pain or pain in your side .This means the infection may have reached your kidneys
- · You feel feverish, shivery, or generally very unwell alongside urinary symptoms
- · Your symptoms are getting worse instead of better
Your doctor will test your urine to find out which bacteria is causing the infection. You will be given a short course of pregnancy-safe antibiotics — usually 3 to 7 days. Finish the entire course even if you feel better after two days. Do not try to treat a UTI in pregnancy with home remedies or cranberry juice alone. You need antibiotics.
To help prevent UTIs: Drink plenty of water throughout the day. Go to the bathroom after intercourse. Always wipe front to back. Wear cotton underwear. Do not hold your urine in for long periods of time.
2. Group B Strep (GBS)
Group B Strep , or GBS , is a type of bacteria that lives naturally in the gut and vaginal area of roughly 1 in 4 healthy women. It causes absolutely no harm to the woman herself. Most women who carry it never even know.
The reason it matters in pregnancy is that GBS can be passed to the baby during labour and delivery. In a small number of newborns it can cause a serious infection affecting the blood, the lungs, or the brain.
The vast majority of babies born to mothers who carry GBS are completely fine. The risk of a baby developing a serious GBS infection is small and with the right treatment during labour, that risk becomes even smaller. This is manageable. You just need to know about it in advance.
Between weeks 35 and 37 of your pregnancy, your doctor will offer you a simple swab taken from the vaginal and rectal area. It is quick and painless. If it comes back positive, you will be given antibiotics through a drip during your labour. This dramatically reduces the risk to your baby.
Nothing. GBS has no symptoms in the mother. You will only know you carry it through the swab test.
Important: Even if you have not been tested , if your waters break more than 18 hours before your baby is born, or if you develop a fever during labour, or if you go into labour before 37 weeks , you will be given GBS antibiotics automatically. Your doctors know to do this.
3. Bacterial Vaginosis (BV)
Bacterial vaginosis , or BV , is when the natural balance of bacteria inside the vagina gets disrupted and certain bacteria start to overgrow. It is not a sexually transmitted infection. It is just an imbalance and it is actually very common in pregnancy.
- · A thin, greyish or white discharge
- · A strong fishy smell — often more noticeable after sex
- · Mild itching or irritation
- · Many women have no symptoms at all
If BV is left untreated during pregnancy, it has been linked to an increased risk of early labour, premature waters breaking, and low birth weight. This is why any unusual discharge during pregnancy should always be mentioned to your doctor , not ignored, and not self-treated.
Your doctor will do a simple swab to confirm BV. You will be given pregnancy-safe antibiotics — usually as tablets or a gel. Do not try to treat it yourself with over-the-counter products. You need the right diagnosis and the right treatment.
BV and thrush are different. Thrush , a yeast infection ,is also more common in pregnancy. It causes a thick white discharge that looks like cottage cheese, with intense itching. It feels very different from BV. Both are common. Both need to be checked and treated by your doctor. Do not guess which one you have . let your doctor swab and confirm.
4. Toxoplasmosis
Toxoplasmosis is an infection caused by a tiny parasite. In healthy adults it usually causes nothing or maybe mild swollen glands and tiredness that you would not think twice about. But if it is caught during pregnancy and crosses the placenta, it can cause serious problems for the baby affecting the brain, the eyes, and other organs.
- · Raw or undercooked meat — especially lamb, pork, and game meat
- · Cat litter — cats can carry this parasite and shed it in their faeces
- · Garden soil — the parasite can live in soil
- · Unwashed fruits and vegetables — if they have been in contact with contaminated soil
Usually nothing at all. Sometimes mild tiredness and swollen glands easy to mistake for a minor cold.
If your doctor suspects toxoplasmosis, a blood test can confirm it. Treatment is available and works well which is why it is important to mention any relevant symptoms or exposures to your OB.
Prevention is simple and works:
- · Cook all meat thoroughly — no pink in the middle
- · Wear gloves when gardening and wash your hands well afterward
- · Ask someone else to change the cat litter box while you are pregnant. If you must do it yourself — gloves on, and wash hands immediately after
- · Wash all fruits and vegetables thoroughly before eating
5. Listeria
Listeria is a bacterial infection that comes from certain foods. Pregnant women are around 10 times more likely to get listeria than other healthy adults because of how the immune system adjusts in pregnancy.
In the mother, listeria can feel like mild flu I.e. fever, muscle aches, nausea, diarrhoea. The reason it is taken so seriously in pregnancy is that it can cross the placenta and reach the baby directly. It can cause miscarriage, stillbirth, early labour, or serious illness in a newborn.
These are the foods to completely avoid during pregnancy:
- · Soft cheeses that are unpasteurised — brie, camembert, blue cheese, certain feta cheeses
- · Any kind of pâté — meat, fish, or vegetable
- · Ready-to-eat smoked fish and smoked seafood
- · Deli meats and pre-packaged sliced meats that have been sitting out
- · Soft-serve ice cream
- · Unpasteurised milk or juices
Fever, muscle aches, nausea, and loose stools — very similar to a stomach bug or mild flu. Symptoms can appear anywhere from a few days to a few weeks after eating contaminated food.
You are pregnant and develop a fever with flu-like symptoms — always call your OB. Do not assume it is just a virus. Listeria is treated with antibiotics, and catching it early makes a real difference.
The simplest prevention: Avoid the foods on the list above completely. Reheat all leftovers until they are steaming hot all the way through. Keep your fridge cold — below 5°C. Eat freshly prepared food as much as possible. These are small, easy habits that carry a lot of protection.
6. Rubella (German Measles)
Rubella is a virus. In adults it causes a mild rash, a slight fever, and some swollen glands . Most people barely notice it. But rubella caught in the first 12 weeks of pregnancy can cause very serious damage to a developing baby affecting the heart, brain, eyes, and ears. This is called Congenital Rubella Syndrome.
Most women are already immune to rubella either from a childhood vaccination or from having had it as a child. Your immunity is checked with a simple blood test at your very first prenatal appointment. Most women find out they are already protected and never need to think about it again.
You cannot be vaccinated during pregnancy because the rubella vaccine is a live vaccine. So during your pregnancy, you will be advised to avoid anyone who has rubella. After your baby is born, you will be vaccinated straight away so you are fully protected for any future pregnancies.
If you are planning a pregnancy and have never been vaccinated , get a rubella vaccination now, wait one month, and then start trying. This one vaccine eliminates the risk entirely.
7. CMV (Cytomegalovirus)
CMV is a very common virus. By the time most people reach adulthood, more than half have already had CMV without ever knowing it, because it causes little to no symptoms in healthy people. A bit of tiredness. Maybe some swollen glands. Easy to miss.
In pregnancy, however, if you catch CMV for the first time or if a previous CMV infection reactivates , it can sometimes cross the placenta. CMV is actually the most common viral cause of birth defects in children. It can cause hearing loss, vision problems, and developmental delays in the baby.
CMV spreads through close contact with another person's bodily fluids I.e. saliva, urine, tears. The most common way it spreads to pregnant women is through young children. Changing nappies, wiping a toddler's nose, sharing food or a spoon, a child coughing near your face , these are all ways CMV can spread.
There is no vaccine for CMV yet. Prevention is the key.
Simple habits that reduce your risk significantly:
- · Wash your hands thoroughly after changing nappies or wiping a child's nose
- · Do not share food, drinks, or utensils with young children
- · Do not let a young child kiss you on the mouth
- · Do not share a toothbrush
If you work in a nursery, school, or childcare setting — mention this to your OB. They may want to discuss additional precautions with you.
8. Chickenpox (Varicella)
Most adults are already immune to chickenpox because they had it as a child. But if you have never had chickenpox and have not been vaccinated, pregnancy is not the time to catch it for the first time.
Chickenpox in pregnancy can be serious for the mother causing severe pneumonia in some cases. And it can also affect the baby. If caught before 28 weeks, there is a small risk of a rare condition called fetal varicella syndrome affecting the baby's skin, eyes, and limbs. If caught very close to the time of delivery, the newborn can be born with active chickenpox and no immune protection.
The classic chickenpox rash I.e. itchy red spots that turn into blisters, spreading across the body. Fever, tiredness, and feeling generally unwell come first, usually a day or two before the rash appears.
If you think you have been in contact with someone who has chickenpox or with someone who has shingles (which is caused by the same virus) and you are not sure whether you are immune , call your OB the same day. Do not wait and see.
A blood test can quickly confirm whether you are immune. If you are not immune, there is a treatment called VZIG (Varicella Zoster Immune Globulin) , an injection that can reduce the severity of chickenpox if given within 10 days of exposure.
If you are planning a pregnancy and are not sure whether you have had chickenpox, ask your doctor to check your immunity. If you are not immune, you can be vaccinated before you start trying to conceive.
9. Zika Virus
Zika is a virus spread mainly through the bite of infected mosquitoes specifically a type of mosquito found in tropical and subtropical regions. It can also be spread through sexual contact with a person who has been infected.
In adults, Zika usually causes very mild symptoms I.e. a slight fever, a rash, joint pain, and red eyes for a few days. Many people feel nothing at all.
In pregnancy, however, Zika can cause a serious condition in the baby called microcephaly where the baby's brain does not develop properly and the head is smaller than normal. It is also associated with other severe brain defects.
If you are pregnant or trying to conceive ,check the travel advisories for your destination before any international trip. Countries in South America, Central America, parts of the Caribbean, Southeast Asia, and parts of Africa have had Zika outbreaks.
If you are travelling to or from a Zika-affected area:
- · Use strong mosquito repellent — DEET-based is safe in pregnancy
- · Wear long sleeves and long trousers especially in the morning and evening
- · Sleep under a mosquito net
- · Use condoms during sex for the duration of your trip and for 8 weeks after returning
- · Tell your OB about your travel plans before you go and when you return
10. The Flu (Influenza)
The flu is a respiratory viral infection ,most people know it well. Runny nose, fever, body aches, exhaustion, sore throat. Normally unpleasant but manageable.
In pregnancy, the flu can be significantly more severe. Pregnant women are much more likely to develop complications from the flu including pneumonia, hospitalisation, and in serious cases, very preterm birth. Your heart, lungs, and immune system are all working harder in pregnancy, making your body less able to fight a severe respiratory infection.
Get your flu vaccine. This is the single most important thing you can do to protect yourself from flu during pregnancy. The flu vaccine is completely safe at any stage of pregnancy. It also passes antibodies to your baby ,protecting them in the first few months of life before they are old enough to be vaccinated themselves.
If you do get the flu during pregnancy , rest, stay hydrated, and call your OB. Antiviral medication (such as oseltamivir / Tamiflu) can be prescribed in pregnancy and works best when started within the first 48 hours of symptoms. Do not take ibuprofen, use paracetamol only.
The flu vaccine in pregnancy protects two people at once , you and your baby. It is one of the simplest, most evidence-backed things you can do for your baby's health before they are even born.
11. COVID-19
COVID-19 is caused by the coronavirus SARS-CoV-2. By now, most people have experienced it. For most healthy adults, it causes a respiratory illness ranging from mild to moderate.
In pregnancy, COVID-19 is associated with a higher risk of severe illness compared to non-pregnant women of the same age. It also increases the risk of preterm birth and admission to intensive care. Pregnant women are considered a high-risk group.
Stay up to date with your COVID-19 vaccinations including any boosters recommended during pregnancy. The COVID-19 vaccine is safe in pregnancy and has been given to millions of pregnant women worldwide. It reduces your risk of severe illness significantly.
If you test positive during pregnancy rest, stay hydrated, take paracetamol for fever, and call your OB to let them know. They will advise you based on how far along you are and how you are feeling. Monitor your baby's movements carefully if you feel unwell.
- · Your breathing becomes difficult
- · Your oxygen levels drop
- · You develop a very high fever that does not come down
- · Your baby's movements reduce while you are unwell
The Golden Rules for Staying Safe
All of these infections sound different , but the ways to protect yourself overlap a lot. Here are the habits that protect you from nearly all of them.
This is the single most effective thing you can do. Wash your hands before eating, after using the bathroom, after contact with animals, after changing nappies, after gardening, and after being in public spaces. Use soap and water for at least 20 seconds. Alcohol hand gel when soap is not available.
- · Cook all meat thoroughly — no pink in the middle
- · Avoid the high-risk foods: soft unpasteurised cheeses, pâté, deli meats, raw fish, raw eggs, soft-serve ice cream
- · Wash all fruits and vegetables before eating
- · Store food properly and reheat leftovers until steaming hot
- · Keep your fridge below 5°C
Make sure you are up to date on:
- · Flu vaccine — recommended every pregnancy, at any stage
- · COVID-19 vaccine — recommended and safe in pregnancy
- · Rubella, chickenpox — check your immunity before pregnancy if you can
Any unusual discharge. Any fever. Any rash. Any flu-like symptoms. Any travel to tropical countries. Any contact with someone who has an infection. Your OB cannot help you if they do not know. There is no such thing as an unnecessary call during pregnancy.
- · Ask someone else to change the cat litter box
- · Wear gloves when gardening
- · Do not share food or utensils with young children
- · Wash your hands after handling raw meat
The Things Worth Remembering
- · Most pregnancies pass without any significant infection. This article is not meant to frighten you — it is meant to inform you.
- · Many of these infections are preventable with simple, consistent habits — hand washing, food safety, and vaccinations.
- · Some infections have no symptoms at all in the mother — which is why your urine and blood are tested at every prenatal appointment even when you feel fine.
- · If something feels wrong — a fever, unusual discharge, flu-like symptoms, a rash — call your OB the same day. Do not wait and see.
- · You are not being dramatic when you call your doctor. You are being a good mother.
FAQ’s
I have a cat. Is my baby at risk?
Your cat is not automatically a risk. The toxoplasmosis parasite is shed in a cat's faeces — and only in cats that have recently been infected (usually through eating infected prey like mice). The simplest solution is to ask someone else to change the litter box during your pregnancy. If you live alone and must do it yourself — wear gloves, wash your hands thoroughly, and change the litter daily (the parasite takes 1 to 5 days to become infectious after being shed). Indoor cats that do not hunt are very low risk.
I ate brie before I knew I was pregnant. What do I do?
Do not panic. Listeria infection is actually rare — even among people who eat high-risk foods. If you ate something on the avoid list before you knew you were pregnant, mention it to your OB at your next appointment. If you ate it recently and develop fever or flu-like symptoms, call your OB today. One accidental exposure is not a cause for alarm — consistent avoidance going forward is what matters.
Is the flu vaccine really safe in pregnancy?
Yes — and not just safe, but recommended. The flu vaccine has been given safely to pregnant women for decades. It does not contain a live virus so it cannot give you or your baby the flu. It protects you from severe illness during pregnancy and passes protective antibodies to your baby through the placenta — giving them some immunity in their first months of life before they can be vaccinated themselves.
I have BV. Will it definitely harm my baby?
Not necessarily — and not if it is treated. BV is associated with certain pregnancy risks, but millions of women have BV during pregnancy and go on to have completely healthy babies. The key is to get it diagnosed and treated promptly rather than leaving it untreated. Tell your OB, get the correct treatment, and complete the full course.
What if I get sick and don't know what it is?
Call your OB. Describe your symptoms clearly — when they started, what they feel like, your temperature if you have measured it, any rash, any unusual discharge. They will tell you what to do next. You do not need to diagnose yourself. That is what your doctor is for.
References
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