Oral thrush during pregnancy: causes and treatment

Oral thrush is an infection that can occur frequently during pregnancy and can affect both the mother and the foetus. During this period, the body undergoes numerous hormonal and physical changes, which can also affect oral health. Hormonal changes and alterations in the body’s pH can promote the overgrowth of the Candida fungus, increasing the risk of infection.

Pregnant women are more susceptible to certain opportunistic infections, including oral thrush. During pregnancy, increased levels of glycogen in the mucous membranes can create a favourable environment for the growth of microorganisms. Therefore, early diagnosis of Candida infection or its prevention is necessary for the well-being of both mother and baby.

Oral thrush is an infection caused by the uncontrolled proliferation of Candida in the mouth. Candida is part of the normal oral microflora of healthy individuals, with approximately 30–60% of adults carrying Candida species in their mouths.

Oral thrush begins suddenly, in the form of whitish patches (characteristically resembling ‘curdled milk’) on a background of congested mucosa. The deposits frequently appear on the tongue, the inside of the cheeks, the roof of the mouth, the oropharynx and, less commonly, on the gums.

The causes of oral thrush during pregnancy include hormonal changes, a weakened immune system and nutritional deficiencies. 

A pregnant woman’s immune system is naturally suppressed to allow the foetus to develop, making the body more vulnerable to such infections. 

During pregnancy, women experience significant hormonal fluctuations, particularly increased levels of hormones such as oestrogen and progesterone. At the same time, a marked proliferation of oral microorganisms has been observed, which tend to utilise the steroid hormones of pregnancy for their development. 

“Studies have shown that the presence of pathogenic microorganisms or their metabolic products in the intrauterine environment stimulates an immune and inflammatory response, which may be responsible for an increased risk of preterm birth and low birth weight,””, explains Dr. Irina Popa, a resident in periodontology.

Other factors leading to the development of oral thrush during pregnancy include:

• endocrine disorders (diabetes, hypothyroidism);
• certain medications (antibiotics, corticosteroids, chemotherapy drugs);
• smoking;
• poor oral hygiene;
• dry mouth (xerostomia).

Symptoms can range from mild forms, which cause only discomfort, to more obvious manifestations affecting the oral mucosa. In most cases, the symptoms appear gradually and can be mistaken for other oral conditions. 

Here are the most common symptoms that may indicate a Candida infection during pregnancy:

• whitish patches on the tongue;
• altered, metallic taste;
• a burning or stinging sensation;
• discomfort when chewing or swallowing;
• light bleeding if the white patches are scratched;
• cracks and redness at the corners of the mouth.

Topical antifungal medicines, such as miconazole or nystatin gel, are generally recommended as first-line treatments for mild forms of candidiasis in pregnant women.

For more severe or persistent infections, systemic antifungal therapy (fluconazole, itraconazole or amphotericin B) may be required. 

However, the choice of systemic agents must be made with caution.

Fluconazole remains one of the most widely used drugs, but its use during pregnancy requires an individualised assessment of potential risks and therapeutic benefits. 

In certain cases, a combination of topical and systemic antifungal therapy may be indicated to achieve better results.

Oral thrush – safe treatments during pregnancy:

• Oral antifungal gels (nystatin, miconazole, as recommended by a doctor);
• Rigorous oral hygiene – the dentist can educate the patient on how to improve oral hygiene through correct brushing techniques and the use of aids (dental floss, oral irrigators, interdental brushes, mouthwashes);
• Avoid self-medication.
   

Treatment for oral thrush during pregnancy consists of local antifungal agents recommended by the doctor, which are considered safe for both the mother and the foetus. It is also very important for the mother to maintain rigorous oral hygiene to prevent the uncontrolled proliferation of Candida species in the oral cavity.

The decision regarding antifungal treatment during pregnancy must always be based on a careful assessment of the therapeutic benefits and potential risks. 

Factors such as the type of medication, the dose, the duration of treatment, the gestational age and the mother’s health must be taken into account. 

The use of systemic antifungals during pregnancy may have a negative impact on embryonic development:

• Risk of congenital malformations: some medicines in the azole class have been associated with congenital malformations when used during the first trimester of pregnancy
• Impaired foetal growth and development: some systemic antifungals may restrict intrauterine growth, and the foetus may have a low birth weight
• Reproductive toxicity: certain medicines may affect reproductive development, including genital abnormalities and reduced fertility in offspring.
   

• brushing twice a day (plus using dental floss, interdental brushes or a mouthwash);
• tongue cleaning;
• a balanced diet, dietary supplements (as recommended by your doctor);
• limiting sugar intake, monitoring blood sugar levels;
• changing your toothbrush after antifungal treatment.