What Should Expectant Mums Know About Toxoplasmosis?
Toxoplasmosis tends to crop up whenever we talk about pregnancy, as it’s one of those infections which – if you catch it while you’re expecting – can cause serious developmental problems for the baby. But is it equally risky for everyone?
In healthy adults, if the parasite gets into the body, the immune system usually deals with it easily. You might only notice mild, vague symptoms – think tiredness, a slight temperature, flu-like feelings, swollen lymph nodes – and often there’s no clear cause identified.
When the immune system is immature or weakened – such as in unborn babies and newborns – the infection can do real harm: eye inflammation or even blindness, lung infection, calcifications in the brain, hydrocephalus, neurological or eye symptoms after birth, or miscarriage. In these cases the parasite multiplies faster and spreads more easily. The highest-risk situation is when a woman with no existing toxoplasmosis antibodies becomes infected during pregnancy and the parasite crosses the placenta to a baby who can’t yet fight it off.
Toxoplasmosis is common – potentially affecting up to half the population. Many infections in pregnancy are symptom-free, and the chance of transmission to the baby rises as pregnancy progresses: around 15% in the 1st trimester, 25% in the 2nd, and 65% in the 3rd. The earlier the infection, the more severe the potential impact, so the first 12 weeks are especially critical.
What’s the culprit?
The parasite is Toxoplasma gondii, a microscopic single-celled organism found almost everywhere on Earth. The illness is a zoonosis – it can pass from animals to humans.
It can infect all mammals and birds, living in vertebrates and humans. Its life cycle involves two hosts: its definitive host is the cat, where it reproduces and produces eggs (oocysts). Those oocysts pass into the environment in cat faeces and can then infect other animals. Humans act as intermediate hosts, where the parasite multiplies.
The parasite has two main forms: a rapidly multiplying form early in infection, and a cyst form that persists in chronic infection. Although cats play a key role, with sensible precautions you can avoid infection. Many cats have previously been infected and will no longer shed the parasite – more on that below.
How can toxoplasmosis be caught?
The best-known route is cat faeces – for example when cleaning a litter tray or via contaminated soil in a sandpit or garden. A cat typically sheds the parasite for about 10 days after first infection; if it encounters the parasite again later, it won’t shed it again.
Contaminated soil, water, and food can also carry the parasite. If soil is contaminated, oocysts can get onto fruit and veg (or onto our hands), and children can ingest them from soil. In meat, only thorough cooking kills T. gondii.
A special point for pregnancy: a new infection in the mother can be passed to the baby via the placenta.
Incubation is roughly 10–23 days after eating contaminated meat, and 5–20 days after exposure to cat faeces, soil or unwashed produce.
How can you avoid toxoplasmosis during pregnancy?
A lot depends on whether you already have antibodies – i.e., you’ve had toxoplasmosis before. If you’re immune, you’re protected even if you encounter the parasite while pregnant. It’s useful to have a blood test to check, especially if you’ve lived with pets or spent time around animals.
If you’re not immune, consider testing every two months during pregnancy so any new infection is picked up early and treated. Because infections are often silent, don’t rely on symptoms – lab testing is key.
What if a test picks up a new infection early?
Treatment should start as soon as possible and continue until birth; the newborn is typically treated for six weeks even without symptoms. With timely action, babies generally do well.
During pregnancy, double down on food hygiene and everyday habits:
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No raw or undercooked meat (including steak tartare and underdone steak); cook meat right through.
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Wash and peel fruit and veg; opt for cooked veg more often.
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Handle raw meat with disposable gloves and use a separate chopping board.
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Ideally skip gardening; if you must, wear gloves.
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If there’s a cat at home, have someone else change the litter daily.
Love your cat? Here’s how to keep everyone safe
There’s no need to rehome a beloved pet. With practical steps the risk is very low – and you can test whenever you want reassurance.
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Arrange daily litter cleaning – preferably by someone else during pregnancy.
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Don’t feed your cat raw meat; avoid hunting opportunities.
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Wash hands often after stroking your cat; avoid letting your pet near your face.
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Schedule periodic toxoplasmosis tests for yourself if you’d like extra peace of mind.
How does screening work?
It’s a straightforward blood test. Results show whether you have antibodies (past infection and protection) or a current infection that needs immediate treatment. That timing matters: past infection means protection; current infection means prompt therapy.
Good to know…
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Your cat can be given a quick test to see if it has already had toxoplasmosis. If it has, it won’t shed the parasite again.
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Your own screening reveals whether you’re immune, or whether there’s a recent infection. If so, follow-up testing can help estimate when it started and what it means for the baby.
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For mums-to-be in higher-risk groups (cat owners, gardeners), lab testing is especially helpful.
Sources:
NHS — Toxoplasmosis: causes, risks, prevention and when to seek help
