When you're pregnant, it's normal to have a slight increase in vaginal discharge, particularly in the third trimester. Normal vaginal discharge will be pretty familiar to you, and it's usually odourless, but sometimes can have a mild smell (nothing too offensive) and is often thin and transparent. Yellow discharge, on the other hand, is not normal and could be the symptom of an underlying infection.
To get some expert advice and guidance, we spoke to Dr Deborah Lee, Dr Fox Online Pharmacy, who explains what causes yellow discharge during pregnancy and when to seek help.
Is discharge in pregnancy normal?
"All women have some vaginal discharge, but this naturally increases during pregnancy. The discharge is caused by the production of cervical mucus and normal vaginal transudate, which is tissue fluid that passes through the vaginal walls. Vaginal discharge contains dead cells from the genital tract, mucus, bacteria and white blood cells. Note that the vagina is self-cleansing, and producing a discharge is a way of expelling unwanted material," says Dr Deborah.
What is yellow discharge during pregnancy?
From cervical mucus to the pink discharge at the end of your period, you're likely already familiar with seeing a change in your discharge. During pregnancy, an 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. Any discharge that smells stronger than usual or is offensive should be reported to your midwife or GP. Yellow discharge is usually darker yellow, thick or lumpy, or pale yellow and watery. It may sometimes indicate an infection, and if infections are left untreated, they may lead to complications.
What does yellow discharge during pregnancy mean?
Dr Deborah explains, "It's normal for vagina discharge to increase during pregnancy. Usually, the discharge is clear or whitish, thin and watery." However, she notes, "If it changes in colour or becomes thick, lumpy or foul-smelling, you should seek medical help."
If you experience itching, burning, or any greenish or grey discharge, this could also be a sign of infection. Testing for vaginal and urinary infections could involve a simple urine sample and/or a vaginal swab. Test results may take a couple of days to process. Still, 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.
When to seek help if you have yellow discharge during pregnancy
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 or midwife, who can organise treatment if required. Seeking advice about discharge in pregnancy is wise, as treatment can be different.
It's important to get an assessment from your midwife or GP as advice and/or treatment is available for the following conditions:
Bacterial vaginosis (BV)
"Remember the vagina is self-cleansing and you need those lactobacilli to keep the vagina healthy," explains Dr Deborah. "Normally, the vagina is full of healthy bacteria called lactobacilli, which produce lactic acid. Suppose something leads to a loss of lactobacilli - such as bubble bath, shower gel, vaginal douches – the number of lactobacilli falls. In that case, the pH rises and becomes more alkaline, and other bacteria can grow and multiply," she says. When the balance of microbes that live in the vagina is disturbed by hormonal changes, the bacteria that cause BV can grow and may cause some or a combination of yellowy, vaginal/vulval itching, offensive odour, stinging or burning when passing urine. Around 10-12 per cent of pregnant women can have BV at some stage, and most pregnancies are unaffected by this.
Thrush or yeast infection
"Thrush is very common in pregnancy," says Dr Deborah, with approximately 40 per cent of pregnant women being affected. "It is caused by colonisation of the vagina by Candida organisms. Candida is a fungal infection caused by yeast organisms which can be found incidentally in the healthy vagina of both pregnant and non-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, irritation, and a white curdy discharge. Candida organisms grow well when oestrogen levels are high, as in pregnancy," she says.
Discharge is often thick, white/yellow, and lumpy and is usually described as cottage-cheese-like. It can also cause itching, redness, heat, swelling, an odour, and pain when passing urine or having sex. If you suspect this, contact your midwife or GP for assessment, as they can advise on 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 that would continue trickling or may come with a gush. If you suspect the waters are leaking or have broken, 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 is the most common bacterial STI, and Chlamydia in pregnancy can cause problems during pregnancy and birth, as well as fertility problems. 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 a Sexual Health Clinic without delay," urges Dr Deborah. 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. 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. "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. Deborah. Symptoms that some women may experience include:
• Discharge of yellow mucus and pus from the vagina
• Painful urination
• Abnormal vaginal bleeding
Trichomoniasis 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. You 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
STIs
"Unfortunately, STIs have evolved to survive in the genital tract without causing symptoms, so many women have STIs and remain unaware. STIs have significant harmful consequences for pregnancy," explains Dr Deborah. If you are pregnant and sexually active, even if you have no symptoms, you should go and get tested if
• You are 25 and under
• You’ve never had any STI tests
• You think your partner may have been unfaithful
• Your partner has been recently diagnosed with an STI
• You have sex outside of your regular relationship
• You’ve been sexually assaulted, abused or raped or a victim of domestic violence.
• You are an IV drug user
• You work in the sex or porn industry
• You are vulnerable or disadvantaged, for example, having been in care, or if you have a disability.
"If you test positive for an STI, you must 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 responsible thing to do. The well-trained staff will do their best to put you at ease. The service is confidential, and your GP does not necessarily need to be informed. However, it would be best to keep your GP fully current, especially as you are pregnant," says Dr Deborah Lee.
Meet the expert
Dr Deborah Lee has years of experience working for the NHS but 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.
About the author
Stephanie Spencer is the Hub Editor of Motherandbaby.com and recently welcomed her first baby. With a digital publishing career spanning over 10 years, starting out as an editorial assistant on medical journals and moving on to become a news writer and features editor, Stephanie started at Bauer Publishing in 2019 and began working for Mother&Baby in 2020.