In this article:
What Is Chorioamnionitis?
Chorioamnionitis is a bacterial infection of the fetal membranes (chorion and amnion), placenta, and amniotic fluid. It develops when bacteria (most commonly those that normally reside in the vagina) migrate upward and infiltrate the uterus.Common culprits include:
- Group B Streptococcus (GBS)
- Escherichia coli (E. coli)
- Mycoplasma hominis
- Ureaplasma urealyticum
Why Chorioamnionitis Matters for Pregnancy and Labour
Chorioamnionitis is linked to multiple pregnancy complications:- Preterm labour: Infection often triggers early contractions and cervical dilation.
- Maternal sepsis: Infection may enter the bloodstream, causing systemic illness.
- Fetal tachycardia and distress: The baby’s elevated heart rate is a frequent early clue.
- Neonatal sepsis or pneumonia: The baby can inhale infected amniotic fluid or acquire bacteria during delivery.
- Uterine infections postpartum: These may require IV antibiotics and a longer recovery.
- Increased NICU admissions: Especially if preterm delivery occurs.
Who Is More Likely to Develop Chorioamnionitis?
Chorioamnionitis affects the birthing parent, but it also poses serious risks for the baby. Understanding which situations make the birthing parent more vulnerable can help you recognise when extra monitoring, faster action, or preventive steps might be needed:- Your water breaks early and labour is delayed: The longer the time between your water breaking and delivery, especially beyond 18 hours, the more likely it is that bacteria will travel upward and cause infection.
- Labour goes on for too long: Particularly in first-time pregnancies, prolonged or difficult labour increases your risk, especially if internal exams are frequent.
- You’ve had multiple vaginal checks during labour: While sometimes necessary, each internal exam increases the chance of bacteria entering the uterus, especially after the membranes have ruptured.
- Your baby is being monitored internally: Tools like scalp electrodes or intrauterine pressure catheters involve placing instruments into the uterus, which slightly raises infection risk.
- You have an untreated vaginal or urinary infection: Bacterial vaginosis, STIs, or a UTI during pregnancy can create an entry point for bacteria to move into the uterus.
- You've had chorioamnionitis before: If you've experienced this in a past pregnancy, your care team may monitor you more closely this time, as you're at slightly higher risk again.
- Your immunity is lower than usual: Conditions like gestational diabetes, HIV, or even long-term use of steroids can weaken your body’s ability to fight infection.
- Meconium in your waters or poor oral health: Some research suggests that meconium-stained fluid or untreated gum disease may increase overall inflammation and make the uterus more susceptible.
Recognising the Warning Signs
Chorioamnionitis is typically identified through a combination of maternal and fetal signs:- Maternal fever: A single temperature of 39.0°C (102.2°F) or higher, or two consecutive readings of 38.0–38.9°C (100.4–102.0°F) taken 30 minutes apart
- Tachycardia: Heart rate over 100 bpm in the birthing parent or over 160 bpm in the fetus
- Uterine tenderness: Pain or sensitivity in the uterus, especially between contractions
- Foul-smelling vaginal discharge or amniotic fluid: An unusual odour can signal bacterial presence
- Leukocytosis: An elevated white blood cell count, typically found via blood tests
How Doctors Diagnose It
There is no single definitive test, but diagnosis typically includes:- Clinical evaluation: Monitoring fever, uterine tenderness, and maternal/fetal heart rates
- Blood tests: Elevated white cell count and inflammatory markers like CRP
- Amniocentesis (rare): To test for pathogens in amniotic fluid if infection is suspected before labour
- Fetal monitoring: Persistent tachycardia or signs of distress
Treatment: Fast and Targeted
The gold standard treatment is to administer broad-spectrum intravenous antibiotics immediately, often before lab confirmation. Common regimens include:- Ampicillin and Gentamicin: For labouring patients
- Add Clindamycin or Metronidazole post-C-section to cover anaerobic bacteria
After delivery, the birthing parent usually receives antibiotics for an additional 24–48 hours. Newborns are monitored for signs of sepsis, and some may receive IV antibiotics even if asymptomatic.
Prevention and Early Screening
There’s no guaranteed way to prevent chorioamnionitis, but risks can be reduced:- Screen and treat STIs or vaginal infections early in pregnancy
- Limit vaginal exams, especially after membrane rupture
- Maintain good oral hygiene, which is linked to reduced systemic inflammation
- Discuss antibiotic prophylaxis with your doctor if you tested positive for Group B Strep
What Happens to the Baby?
Babies exposed to chorioamnionitis may need:- NICU admission for close monitoring
- Blood cultures, lumbar puncture, and chest X-rays to rule out sepsis or pneumonia
- Antibiotic therapy for 5–7 days, depending on symptoms and lab findings
- Low birth weight
- Difficulty breathing (due to lung immaturity)
- Rarely, long-term neurodevelopmental challenges
Emotional Toll and Support Resources
A sudden infection diagnosis, emergency delivery, or NICU stay can be emotionally distressing. You might feel confused, guilty, or helpless.Here’s how to care for yourself:
- Ask your doctor to explain every step in plain language.
- Involve your partner or support person during key decisions.
- Focus on short-term milestones, not blame or regret.
- Seek out postpartum counsellors at hospitals or helplines like iCall or Fortis Mental Health Support.
- Join NICU parent support groups to process your experience.
FAQs on Chorioamnionitis (Amniotic Fluid Infection): Causes, Risks, and What Pregnant People Should Know
- Can I prevent chorioamnionitis entirely?
You can reduce risk by managing infections early, limiting internal exams, and maintaining hygiene, but not all cases are preventable. - Will I always need a C-section?
No. Many patients deliver vaginally. Surgery is only done if medically needed. - Will my baby have long-term issues?
Most newborns recover fully with prompt care. Complications are more likely in preterm or very low birthweight babies.
