What does yellow discharge during pregnancy mean?

When you're pregnant, you're much more in tune with your body, just like when you were looking out for symptoms of ovulation and getting to know your menstrual cycle better with the likes of an ovulation calculator. So if you've noticed yellow discharge during pregnancy, you may be feeling worried about what this might mean for you and your baby and what you should do about it.

What is yellow discharge during pregnancy?

From cervical mucus to the pink discharge at the end of your period, you may already be used to seeing a change in your discharge. During pregnancy, some increase in vaginal discharge, known as leukorrhea, can be expected as your hormones, oestrogen and progesterone, change. This discharge should be clear, whiteish or even cream or pale yellow. Any discharge that is an unusual colour, including yellow, can be reported to your midwife or GP who after discussing with you, may advise testing. Yellow discharge may indicate an infection and if infections are left untreated they may lead to complications such as waters breaking early or premature birth.

We spoke to midwife and co-founder of My Expert Midwife, Lesley Gilchrist, who said: "Yellow discharge can be anything from a pale lemon through to a bright or deep yellow. Pregnancy puts added stress on to your bladder, particularly in later stages which can cause urine leakage. Urine in pregnancy may be stronger in colour if you are not keeping well hydrated and may add a yellow tinge to your usual discharge, however, if unsure, seek advice from your healthcare provider.

Other yellow discharge may be more obvious and could be thin and watery, thick, frothy, or lumpy in appearance. Normal vaginal discharge either has no smell or has a very inoffensive smell, any discharge that smells stronger than normal or is offensive should be reported to your midwife or GP.

What does yellow discharge during pregnancy mean?

Yellow discharge in pregnancy, especially when accompanied by an offensive odour could indicate an infection and we would recommend that you seek advice from your midwife or GP for investigations. Testing for vaginal and urine infections could involve a simple urine sample and/or a vaginal swab. Test results may take a couple of days to process, but your GP or midwife may organise for you to have a course of antibiotics which may be stopped if results are negative or changed if the results suggest a preferable alternative.

Conditions that have yellow discharge as a symptom

Yellow discharge does not necessarily mean there is infection, however, it is important to get an assessment from your midwife or GP as advice and/or treatment is available for the following conditions:

Bacterial Vaginosis (BV)

When the balance of microbes that live in the vagina are disturbed by hormonal changes, antibiotic use or by using harsh chemical products in the bath or shower, the bacteria that cause BV can grow and may cause some or a combination of the following: yellowy, vaginal/vulval itching, offensive odour, stinging or burning when passing urine. Around 10-30 per cent of pregnant women can have BV at some stage and most pregnancies are unaffected by this.

Yeast Infection

Also known as thrush, yeast infections are common in pregnancy due to hormonal changes, with approximately 30 per cent of pregnant women being affected. Discharge is often thick, white/yellow and lumpy and is often described as cottage-cheese-like. It can also cause itching, redness, heat, swelling, have an odour and causes pain when passing urine or having sex. Contact your midwife or GP for assessment if you suspect this as treatment can advise the treatment during pregnancy.

Rupture of Membranes or simply waters leaking or breaking.

The amniotic fluid is the water that your baby floats around in inside the amniotic sac. If this sac develops a leak or ruptures, you may experience a clear or straw-like pale yellow fluid which would continue to trickle or may come with a gush. If you suspect the waters are leaking or have broken, then contact your local maternity unit for advice.

Sexually transmitted infections (STIs)

All of these STIs can be treated during pregnancy, so contact your health care provider, midwife or doctor if you have symptoms or suspect you could have an STI:

Chlamydia is an STI, however, you may not experience any symptoms so you can be unaware you have been infected. Chlamydia in pregnancy can cause problems during pregnancy and birth as well as fertility problems. Symptoms can include the following:

• Pain when passing urine

• Increased vaginal discharge which may be yellow

• Pelvic and abdominal pain

• Pain or bleeding during/after sex

Gonorrhoea can pass from mother to baby during birth. Symptoms that some women may experience include:

• Discharge of yellow mucus and pus from the vagina

• Painful urination

• Abnormal vaginal bleeding

Trichomoniasis may not always have symptoms however some of these can indicate this infection:

• Abnormal vaginal discharge that may be yellow-green

• Increased amount of discharge which may have an unpleasant smell

• Itching, painful, and swollen vagina and vulva

• Pain when passing urine or having sex

Is yellow discharge during pregnancy a sign that something is wrong?

Yellow discharge is not always a sign that something is wrong. Some women naturally produce discharge that is slightly yellow in colour and this could be something as simple as diet-related. If your normal vaginal discharge is a pale yellow then usually there is no cause for concern but as a rule of thumb if your discharge has changed in colour, texture, or smell then we would recommend you seek advice from your midwife or GP to rule out any infection that could cause complications in your pregnancy.

When to seek help

During your pregnancy, it is important that if you notice any changes to anything including a change in colour to your normal vaginal discharge, you seek advice from your healthcare providers, either your GP, your midwife, or your obstetrician as they can organise tests and treatment if required. Seeking advice about discharge in pregnancy is wise as treatments recommended may be different to if you were not pregnant.

Don’t be afraid or embarrassed to discuss anything with your midwife or doctor, including discharge; there is very little that they will not have seen or heard before, says Lesley Gilchris.

We also spoke to Dr Deborah Lee, Dr Fox Online Pharmacy who said: "All women have some vaginal discharge, but this naturally increases during pregnancy. The discharge is caused by the production of cervical mucous, and normal vaginal transudate which is tissue fluid that passes through the vaginal walls. Vaginal discharge contains dead cells from the genital tract, mucous, bacteria and white blood cells. Note that the vagina is self-cleansing, and producing a discharge is a way of expelling unwanted material.

It's normal for vagina discharge to increase during pregnancy. Usually, the discharge is clear or whitish in colour, and thin and watery. If it changes in colour or becomes thick, lumpy or foul-smelling, you should seek medical help, says Dr Deborah Lee.

Vaginal discharge can be yellow, grey, green, pink, brown or blood-stained. In fact, although the colour gives a clue to the diagnosis, this is not a fail-safe way to make a diagnosis. If your discharge has changed or is troubling you, you must see your GP or go to the Sexual Health Clinic promptly, where the necessary swabs and tests can be carried out.

Causes of a yellow discharge

Yellow discharge can be caused by the following:

Bacterial vaginosis (BV)

BV is very common. In one UK study, BV was present in 12% of pregnant women attending an antenatal clinic. BV is not an STI. In general, it is not a serious condition and if you have it, there is no need to be overly worried or anxious.

Normally, the vagina is full of healthy bacteria called lactobacilli which produce lactic acid. Hence the pH of the vagina is acidic, and this helps prevent any unwanted bacteria from growing there. If something leads to a loss of lactobacilli  - such as bubble bath, shower gel, vaginal douches or the use of any other hygiene products – the number of lactobacilli falls, the pH rises and becomes more alkaline, and other bacteria can grow and multiply. These are bacteria such as Gardnerella, Prevotella and other mixed anaerobic bacteria. They typically produce amines which give the discharge its characteristic fishy smell, says Dr Deborah Lee.

According to the National Institute for Clinical Excellence (NICE), women should not be routinely screened in pregnancy for BV. But if a woman has symptoms, the tests should be taken, and treatment offered.

BV is diagnosed by taking a high vaginal swab, and also testing the vaginal pH with pH paper.

In the Sexual Health Clinic microscopy is performed on vaginal secretions. The characteristic findings are large numbers of white cells, and the presence of clue cells, which are epithelial cells with bacteria attached to the cell surface, continues Dr Deborah Lee.

BV is treated with the antibiotic metronidazole 400 mg twice a day or intravaginal 0.75% gel for 5 days. Alternatively, it can be treated in the second or third trimester with 2% clindamycin vaginal cream used nightly for 7 nights.

The most important thing is to think about why it might have happened. Remember the vagina is self-cleansing and you need those lactobacilli to keep the vagina healthy. There is no need to wash out the vagina, or use anything down there such as baby wipes, vaginal douches or sprays – these all contain chemicals which are irritants and can cause itching, burning and sensitivity, as well as destroy the natural flora of the vagina, says Dr Deborah Lee.

For best results, shower rather than bath. Shower once a day. Just run the water over the genital area but do not squirt water, shower gel or anything else up inside the vagina. Afterwards, pat the area dry with a clean towel. If you really want to use soap down there, use a small blob of emollient – such as Hydromol, E45 cream or Doublebase – as a soap substitute. Rub it gently onto the vulva and splash it off with water. Emollients are generally additive-free. For women with recurrent BV, it's best not to wash your hair in the shower – do this over the basin – to avoid any shampoo or conditioner getting into the vagina.

Smoking also increases the risk of BV. It's always imperative you do all you can to stop smoking in pregnancy, says Dr. Deborah Lee.

If BV is recurrent and troublesome, speak to your midwife or Obstetrician for the best advice. Sometimes women are advised to use medication regularly to stop BV from recurring. This is called prophylaxis.

Thrush – Acute vulvovaginal candidiasis

Thrush is very common in pregnancy  - the proper term is vulvovaginal candidiasis. It is caused by colonisation of the vagina by candida organisms – most often Candida albicans but sometimes by other species. Candida is a fungal infection caused by yeast organisms which can be found incidentally in a healthy vagina, says Dr Deborah Lee.

In some studies, around 40% of pregnant women are found to have candida present in their vaginas, although most had no symptoms. Around 20% - 30% of women will have at least one attack of vulvovaginal candidiasis in their pregnancy.

Candida can be found commonly in the vaginas of both pregnant and no pregnant women often causing no symptoms. But if the yeast starts to grow and reproduce, the hyphae (filaments) branch out and burrow into the epithelial skin surface, causing intense burning and irritation, along with a white curdy discharge. Candida organisms grow well when oestrogen levels are high, as in pregnancy, says Dr Deborah Lee.

Although typically, candida causes a white cottage cheese-like discharge, it can be present if the discharge has a different colour. For example, BV and candidiasis can occur at the same time. In the clinic, candida will always be considered and tested for in any pregnant woman with a discharge.

Candida infection does not harm the unborn baby or have any effect on the pregnancy. However, if you have any symptoms such as abnormal discharge, burning or itching, go to the Sexual Health Clinic or see your GP without delay, says Dr Deborah Lee.

Candida is diagnosed with a high vaginal swab. However, the spores and hyphae of candida can be seen in the vaginal secretions when a woman has microscopy in the Sexual Health clinic.

Vulvovaginal candidiasis is treated with a 500 mg vaginal clotrimazole pessary, inserted every night for 7 nights. Oral antifungal medication is best avoided in pregnancy when possible. It's also very important to avoid using conventional hygiene products and follow the instructions (as for BV) in terms of vulvovaginal hygiene as outlined above. Any of these products contain irritants which cause local inflammation, change the vaginal pH and encourage the growth of unwanted organisms.

Chlamydia

Chlamydia is the most common bacteria STI. In a recent study from The Netherlands, the prevalence of chlamydia in pregnancy was 3.2%. In recent years, the number of cases of chlamydia has been increasing. In the UK, between 2022-2023, the number of cases of chlamydia rose by 8.2%..){href='https://www.gov.uk/government/statistics/sexually-transmitted-infections-stis-annual-data-tables/sexually-transmitted-infections-and-screening-for-chlamydia-in-england-2023-report#:~ =There%20were%20increases%20in%20bacterial,%25%20(6%2C081%20to%206%2C527).' }

Although chlamydia can be harmful in pregnancy, at present there is no routine chlamydia testing in pregnancy in the UK, as there is insufficient evidence to support it. However, if you have been at risk of acquiring an STI, or have symptoms, such as a change in your discharge, you should see your GP or go to the Sexual Health Clinic without delay.

Chlamydia has been found to increase the risk of miscarriage, premature rupture of membranes, preterm delivery and low birth weight. It can also cause neonatal conjunctivitis and pneumonia.

Up to 70% of women with chlamydia have no symptoms. This is why if you have been at risk, you should get tested, even if you are not experiencing any symptoms. If you do have symptoms, these include abnormal vaginal discharge, pain passing urine, abnormal bleeding, pelvic pain and painful sex. If you have any of these symptoms, go to the Sexual Health Clinic or see your GP as soon as possible.

Chlamydia is diagnosed by taking a vulvovaginal swab, which you may be asked to do yourself in the toilet. Alternatively, the doctor or nurse may examine you and take the swab at the same time. You may also be asked to provide a urine sample. The chlamydia test is a nucleic acid amplification test (NAAT test) which is very sensitive.

If chlamydia is present in pregnancy, it needs to be promptly treated. The first choice treatment is a single dose of the antibiotic azithromycin, although there are other options.

For more information – NHS - Chlamydia

Gonorrhoea

Gonorrhoea is an STI which can be present in pregnant women. In a recent 2022%20.){href='https://pubmed.ncbi.nlm.nih.gov/35998807/#:~ =The%20worldwide%20pooled%20prevalence%20of,%25)%20(0.27%2D0.84%25).' } publication, the prevalence of gonorrhoea in pregnancy in European countries was 0.52%. Gonorrhoea is a serious infection which can have significant consequences for both mother and baby. In the UK, between 2022-2023, the number of cases of gonorrhoea rose by 9.4%..){href='https://www.gov.uk/government/statistics/sexually-transmitted-infections-stis-annual-data-tables/sexually-transmitted-infections-and-screening-for-chlamydia-in-england-2023-report#:~ =There%20were%20increases%20in%20bacterial,%25%20(6%2C081%20to%206%2C527).' }

Around 50% of women infected with gonorrhoea will not have any symptoms, which is why it's vital to go for STI testing if you have been at risk. If symptoms do occur, the most common are abnormal vaginal discharge, pain passing urine and pelvic pain.

Gonorrhoea causes intense inflammation, first at the cervix, but it can ascend the genital tract to affect the endometrium (lining of the womb), the fallopian tubes, ovaries and the peritoneum (cells lining the pelvic/abdominal wall). It can cause meningitis, endocarditis and sepsis. Just like chlamydia, gonorrhoea in pregnancy increases the risk of miscarriage, premature rupture of membranes, preterm delivery and low birth weight, and can also cause neonatal conjunctivitis, says Dr. Deobrah Lee.

If you have been at risk of an STI, or have any symptoms including a change in your vaginal discharge, visit the Sexual Health Clinic or see your GP without delay.

Gonorrhoea is diagnosed with a swab taken from the cervix and/or a urine sample. These are nucleic acid amplification (NAAT) tests which are very sensitive. Swabs are also taken from the cervix to try and culture the gonococcal organisms. In the Sexual Health clinic, samples of cervical secretions can be examined under the microscope and gonorrhoea may be identified.

The first-line treatment for gonorrhoea in pregnancy is an intramuscular injection of the antibiotic ceftriaxone 250 mg. You will be asked not to have sex on treatment, and to reattend the clinic in 3 weeks for a repeat test – a test of cure – to check it has been eradicated. All recent sexual partners also need to be treated.

Trichomonas vaginalis (TV)

TV is a parasite that swims in vaginal secretions. It is an STI. When present, it often causes severe irritation, burning and discomfort in the vulvovaginal area. Vaginal discharge may be green, grey or yellow, thin and watery or frothy, and can have a foul smell. Sometimes it may be present with no symptoms, says Dr Deborah Lee.

TV in pregnancy is linked to premature delivery and a low birthweight.

The advice is the same - If you have been at risk of an STI, or have any symptoms including a change in your vaginal discharge, visit the Sexual Health Clinic or see your GP without delay.

TV is usually diagnosed in the Sexual Health Clinic when the TV organisms can be seen swimming in vaginal secretions under the microscope. It can also be cultured from a high vaginal swab.

TV is treated with the antibiotic metronidazole, 400 mg taken twice a day for 5-7 days. As with other STIs, there should be no sex on treatment, and your most recent sexual partner(s) should also be treated at the same time, continues Dr Deborah Lee.

Urine

Up to 40% of women experience incontinence, usually stress incontinence, during pregnancy. This means they involuntarily pass urine when they laugh, cough or sneeze. It’s caused by the pressure of the expanding uterus onto the bladder. Pregnant women may notice they have to go to the toilet to pee more often and have to get up at night.

If you have a yellow discharge, it might mean you are leaking urine. Again, you should discuss this with your GP, midwife or Obstetrician. They will exclude possible diagnoses such as a urinary tract infection (UTI) or diabetes which can occur in pregnancy, continues Dr Deborah Lee.

After the pregnancy, it's important to follow advice carefully and do your pelvic floor exercises.

Leaking amniotic fluid

Your baby is growing inside a sac filled with fluid called amniotic fluid. The baby is suspended in the fluid which protects it from knocks and bumps as it grows. Sometimes, amniotic fluid can leak especially towards the end of pregnancy.

In around 2 in 100 pregnancies, membranes can rupture before 27 weeks of gestation – this is known as premature rupture of membranes. If this happens, you will feel a sudden gush of warm fluid down below. If you suspect this has happened, you need to contact your local maternity unit right away.

Premature rupture of membranes is diagnosed by performing a vaginal speculum examination, where fluid may be seen flowing from the cervix. A testing strip may be used to measure the pH, which will be raised to 6 or above if this is indeed amniotic fluid.

The management of premature ruptured membranes depends on the gestation and other factors. If you are 37 weeks plus, 90% of women will go into labour spontaneously within the next 24 hours. Alternatively, between 34-27 weeks gestation, the baby may need to be delivered and admitted to the neonatal intensive care unit. Before 34 weeks, you will be admitted to hospital and kept on bed rest. You will be given steroids to help mature the baby's lungs. It's also vital to be monitored for infection, says Dr Deborah Lee.

General information

Unfortunately, STIs are very clever, and they have evolved to survive in the genital tract without causing symptoms – after all – if you knew they were there, you would go and get treatment – so they prefer to live there undisturbed.

Because of this many women have STIs and remain totally unaware. And STIs have significant harmful consequences for pregnancy.

If you have any abnormal discharge, get yourself to the Sexual Health Clinic. You can’t self diagnose a vaginal discharge by the colour  - this just makes certain things more likely. The only way to know what it is, is to be seen and have the correct tests.

If you are pregnant, even if you have no symptoms, you should go and get tested if

If you test positive for an STI, it's vital you follow the instructions for treatment to ensure the infection is eradicated. This means taking all the antibiotics, not having sex until your results are back, and you are told it is OK to do so, and getting your partner and any other recent partners, tested and treated, says Dr Deborah Lee.

Try not to be embarrassed about going to the Sexual Health Clinic. It's a good, responsible thing to do. The staff are well trained and will do their best to put you at ease. The service is confidential and your GP does not necessarily need to be informed, although especially as you are pregnant, it would be best to keep your GP fully up to date", says Dr Deborah Lee.

Meet the expert:

This article contains expert advice from registered midwife and co-founder of My Expert Midwife, Lesley Gilchrist. With extensive experience as a labour ward co-ordinator and as a community midwife, Lesley brings her expertise in pregnancy, postnatal, birth and the birth process to Mother&Baby to keep you informed and empowered.

Having worked for many years in the NHS, mostly as Lead Clinician within an integrated Community Sexual Health Service, Dr Deborah Lee now works as a health and medical writer, with an emphasis on women's health, including medical content for Dr Fox pharmacy. She has published several books and remains passionate about all aspects of medicine and sexual health. After completing her Medical Degree at University of Southampton Medical School in 1986, Dr Lee trained as a GP and after a number of years specialised in Sexual & Reproductive Health (S&RH).