Chlamydia in Pregnancy: Risks, Treatment and Retesting
Why chlamydia needs treating in pregnancy, which antibiotics are used, and the test you’ll need afterwards.
Part of our Chlamydia condition guide.
Get urgent help first. Go to A&E or call 999 for sudden, severe pain in a testicle, or severe pain low in your tummy with a fever, fainting or any chance you could be pregnant. Contact NHS 111 (NHS 24 on 111 in Scotland) or your GP the same day for pelvic pain, pain during sex, bleeding between periods or after sex, or a fever with genital symptoms. Online treatment is not suitable in these situations.
If you’re pregnant and have chlamydia, contact your midwife, GP or a sexual health clinic. It’s easily treated in pregnancy with antibiotics that are safe for your baby, and you’ll need a test afterwards to check it has cleared. Access Doctor’s online service doesn’t treat chlamydia in pregnancy or while breastfeeding.
Key fact: Chlamydia in pregnancy can be passed to your baby during birth, causing an eye infection or a chest infection. Treating it during pregnancy, then checking it has gone, prevents this.
Why chlamydia matters in pregnancy
Chlamydia is common and usually causes no symptoms, so many women only find out they have it from a test during pregnancy. It’s easily treated, but pregnancy changes two things. First, the usual first-choice antibiotic, doxycycline, isn’t normally used, so a different antibiotic is needed. Second, a test after treatment is recommended, because leaving the infection untreated at the time of birth puts the baby at risk.
Risks to you and your baby
Untreated chlamydia in pregnancy has been linked with:
- premature birth;
- the waters breaking early (premature rupture of membranes);
- a low birth weight;
- infection of the womb lining after the birth.
These links come mainly from observational studies, and treating the infection during pregnancy reduces the risks.
Eye infection in the baby
A baby can pick up chlamydia during birth and develop a sticky eye infection (neonatal conjunctivitis), usually in the first couple of weeks. It needs antibiotic treatment.
Chest infection in the baby
Less often, a baby develops chlamydia pneumonia in the first few months, with a cough and fast breathing. It also needs antibiotic treatment.
Both are prevented by treating the mother before the birth. If you had chlamydia that wasn’t treated before your baby was born, tell your midwife or health visitor so your baby can be checked.
Testing in pregnancy
The test is the same as at any other time: a self-taken vaginal swab or a urine sample, both safe in pregnancy. NHS advice is to get tested if you’re under 25 and sexually active, if you have a new partner, or if a partner has had chlamydia. Ask your midwife, GP or a sexual health clinic, or use a free NHS home test kit where available. If you test positive, tell your midwife so your care team can arrange treatment and the follow-up test.
Treatment in pregnancy
UK guidance uses one of these antibiotics in pregnancy. Your midwife, GP or clinic will choose the right one for you.
| Antibiotic | Usual course | Notes |
|---|---|---|
| Azithromycin | 1g as a single dose, or 1g on day 1 then 500mg on days 2 and 3 | The most commonly used option. Large studies of pregnancies exposed to azithromycin haven’t shown an increase in major birth defects. |
| Erythromycin | 500mg four times a day for 7 days, or 500mg twice a day for 14 days | An alternative. Stomach upset is common. |
| Amoxicillin | 500mg three times a day for 7 days | An alternative if macrolide antibiotics aren’t suitable. |
| Doxycycline | Not usually used | It can affect a baby’s developing bones and teeth, and its product information says it shouldn’t be used in pregnancy. |
Decide with your care team. The choice depends on your stage of pregnancy, allergies and other medicines. Please don’t take antibiotics left over from before, or prescribed for someone else.
Not Pregnant and Tested Positive?
If you’re not pregnant or breastfeeding and you’ve tested positive for chlamydia, or a partner has, Access Doctor (GPhC #9011198) can assess you online. If you are pregnant, please contact your midwife, GP or a sexual health clinic instead: treatment in pregnancy needs a follow-up test that an online service can’t arrange. Approved before 3pm, Monday to Friday? Dispatched the same day, by Royal Mail Tracked 48, Tracked 24 or Special Delivery guaranteed by 1pm next working day: you choose.
Start Chlamydia Consultation →Adults only online. Access Doctor’s online chlamydia service is for adults aged 18 and over who are not pregnant or breastfeeding. If you’re under 18, pregnant or breastfeeding, an NHS sexual health clinic or your GP can test and treat you free and in confidence, and under 25s can also get help from Brook.
The test after treatment
Outside pregnancy, a test to prove the treatment worked isn’t usually needed. In pregnancy it is. UK guidance (BASHH) advises the test is done at least 3 weeks after finishing treatment, because testing sooner can pick up leftover traces of the bacteria. NHS advice is that you’ll be retested about 4 weeks after treatment. Some NHS services also offer another test later in pregnancy, around 36 weeks, to check you haven’t caught it again.
If the test is still positive, you’ll be offered more treatment, and your care team will check whether a partner needs treating, because reinfection from an untreated partner is a common cause.
Partners
Anyone you’ve had sex with in the last 6 months should be tested and treated, even if they feel well. Your current partner should be treated before you have sex again, or you could catch it straight back. Don’t have sex until you have both finished treatment; if azithromycin was used, wait until 7 days after the last dose.
Your partner can be treated at a sexual health clinic or by their GP. If they’re 18 or over and not pregnant, they can also use an online service such as ours. A sexual health clinic can tell partners for you without giving your name; see our partner notification guide.
Breastfeeding
If you’re diagnosed with chlamydia while breastfeeding, UK guidance uses the same antibiotics as in pregnancy, such as azithromycin. Doxycycline passes into breast milk and its product information advises against it while breastfeeding. Our online service doesn’t treat chlamydia while you’re breastfeeding, so please speak to your GP or a sexual health clinic, who can weigh up the options for you and your baby.
UK safety, support and free NHS options
Doxycycline and azithromycin are prescription-only medicines in the UK. Before anything is prescribed, a GPhC-registered pharmacist independent prescriber reviews your consultation, including your allergies and the other medicines you take. Always read the patient information leaflet in the pack. Never share antibiotics with anyone else, even a partner with the same infection, and don’t keep leftovers for another time: return unused tablets to a pharmacy.
If you think you’ve had a side effect from a medicine, tell your pharmacist or doctor. You can also report it to the MHRA through the Yellow Card scheme, which helps keep medicines safe for everyone.
NHS sexual health clinics test and treat chlamydia free of charge across the UK, and you don’t need a GP referral: use the NHS website in England, NHS inform in Scotland, Sexual Health Wales in Wales and nidirect in Northern Ireland to find one. Our private chlamydia treatment online service is an alternative for adults aged 18 and over.
If anything about how you got this infection doesn’t feel right, for example if sex wasn’t your choice or a partner pressures or controls you, you can talk to someone in confidence. See support, if you need it for free, confidential helplines. If you’re in immediate danger, call 999.
Frequently Asked Questions
Can chlamydia cause a miscarriage?
The evidence linking chlamydia to miscarriage is limited and inconsistent. The links are stronger with premature birth and the waters breaking early. Whatever your stage of pregnancy, the safest thing is to get tested if you might be at risk and treated promptly if the test is positive.
Is azithromycin safe in pregnancy?
Azithromycin is one of the antibiotics UK guidance uses for chlamydia in pregnancy. There are no large randomised trials in pregnant women, but large observational studies haven’t shown an increase in major birth defects. Your midwife, GP or clinic will discuss the options with you and arrange a test afterwards.
Will chlamydia affect my baby if I’m treated before the birth?
If chlamydia is treated during pregnancy and a test afterwards confirms it has cleared, your baby is very unlikely to be affected. The eye and chest infections happen when the infection is still present at the time of birth.
What happens if I had chlamydia when my baby was born?
Tell your midwife, health visitor or GP so your baby can be checked. Babies who pick up chlamydia at birth can develop a sticky eye infection, usually in the first couple of weeks, or a chest infection in the first few months. Both are treated with antibiotics.
Should I tell my midwife I have chlamydia?
Yes. Your midwife and care team need to know so they can make sure you get an antibiotic that’s safe in pregnancy, arrange the test after treatment and check your baby after the birth. Chlamydia is very common, and your care team’s only concern is looking after you and your baby.
Can I take chlamydia treatment while breastfeeding?
Yes, but the choice of antibiotic matters. UK guidance uses the same antibiotics as in pregnancy, such as azithromycin. Doxycycline’s product information advises against it while breastfeeding. Our online service doesn’t treat chlamydia while you’re breastfeeding, so please see your GP or a sexual health clinic.
Can I get chlamydia treatment online while pregnant?
Not from Access Doctor. Treatment in pregnancy needs a test afterwards and care from your antenatal team, which an online service can’t arrange. Contact your midwife, GP or a sexual health clinic; testing and treatment at NHS sexual health clinics are free.
References
- British Association for Sexual Health and HIV (BASHH). UK national guideline for the management of infection with Chlamydia trachomatis, 2026 (Saunders J, et al.). doi.org
- NHS Scotland Right Decisions. Chlamydia in pregnancy. rightdecisions.scot.nhs.uk
- NICE Clinical Knowledge Summaries. Chlamydia – uncomplicated genital. cks.nice.org.uk
- NHS. Chlamydia: treatment. nhs.uk
- Electronic Medicines Compendium. Azithromycin 500mg tablets: Summary of Product Characteristics. medicines.org.uk
- Electronic Medicines Compendium. Doxycycline 100mg capsules: Summary of Product Characteristics. medicines.org.uk
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.