Sinusitis is an infection of the sinuses that can lead to swelling, tenderness, and a reduced sense of smell. Many of us may have experienced this after a cold or flu.¹ Not all medications are safe during pregnancy and care must be taken to avoid risks and complications. This article will explore how sinusitis can present during pregnancy, the risks to the mother and foetus, and how it can be managed. 

Symptoms

Typical symptoms of sinusitis (which can be chronic or acute) include:¹

• Blocked / runny nose
• Pain, swelling, and tenderness (particularly around the cheeks, eyes, and forehead)
• Reduced sense of smell
• Nasal discharge (green or yellow mucus)
• Fever
• Other: headaches, toothaches, coughing, postnasal drip (where mucus drips down through the throat), pressure in the ears, halitosis (or bad breath), snoring, and sounding nasal

Testing for sinusitis during pregnancy

In addition to the presence of these hallmark symptoms, sinusitis can also be diagnosed through nasal and sinus examination with an endoscope (a long, thin and flexible camera, and light-bearing tube), a mucus culture to determine the cause of the infection, allergy testing, and imaging tests (such as a CT scan or an MRI).²

What causes sinusitis during pregnancy?

It has been found that immune deficiency contributes to the development of chronic rhinosinusitis in some people.³ Pregnant women are considered to have a ‘unique immunological condition’ that helps maintain the well-being of the mother and developing foetus (which is developing an active immune system). This condition can modulate the mother’s immune system during pregnancy, meaning pregnant women may respond differently to pathogens. The mother’s immune system adapts to protect the growing foetus from the stage of implantation of the embryo. 

Growth of the placenta is a key factor, as the placenta has its immune response and can modulate susceptibility, severity, and response to infectious diseases in pregnant women.⁴ 

Hormonal changes during pregnancy may also contribute to the occurrence of sinusitis.⁵ New onset cases of rhinitis occur in 20% of pregnant women. The hormones oestrogen, progesterone, and androgen can all bind to receptors in the nasal passage membrane. It is thought that varying levels of particularly oestrogen and progesterone, which are naturally higher in pregnancy, could be related to the onset of sinusitis.⁸ 

Oestrogen and progesterone can also promote mucus production and lead to post-nasal drip via ‘hypersensitivity reactions’.⁵ Oestrogen has also been seen to increase the occurrences of nasal polyps (small, noncancerous growths in the nasal passages), which are risk factors for sinusitis. Placental growth hormones also play a part. 

However, the mechanisms by which these hormonal changes influence sinusitis in pregnancy are unclear.

Risks related to sinusitis during pregnancy

Sinusitis is generally not likely to harm the foetus, though it can in rare circumstances lead to complications and worsen the severity of symptoms in the mother. Evidence also suggests that ongoing nasal congestion, which can gradually reduce oxygenation, may impact the developing foetus, so early management is important. However, the evidence is inconclusive.

In one study, it was found that body mass index (BMI) and gestational age (i.e., the week of pregnancy) are both significantly associated with rhinitis (inflammation of the nasal passages) which can lead to sinusitis if left untreated).⁶ Multiple pregnancies (which heighten levels of hormones), and women with obesity, excessive weight gain or gestational diabetes are more likely to suffer from rhinitis. 

How to manage sinusitis during pregnancy? 

Medical recommendations

The management of sinusitis in pregnancy has not been extensively studied, and the evidence base is poor. One 2016 systematic review presented a series of recommendations from an expert panel.⁷ 

Medical recommendations for rhinosinusitis based on this study include:

• Particularly where rhinosinusitis is severe, the use of oral corticosteroids in small bursts may be safe during the first trimester, but medical advice should be sought along with diabetes testing
• Nasal corticosteroid use is safe at medically recommended doses (these include, for example, fluticasone, mometasone, and budesonide), but evidence is still lacking. Budesonide is the most widely studied corticosteroid in pregnancy, and 50 micrograms once or twice daily in each nostril should be safe during pregnancy for managing rhinosinusitis
• If sinusitis is bacterial, oral antibiotics may be considered only if they are safe for the foetus. The safest are penicillin and cephalosporin classes of antibiotics. Those that should not be used during pregnancy include: tetracyclines, aminoglycosides, trimethoprim-sulfamethoxazole, and fluoroquinolones 
• Therapy with anti-leukotriene drugs should be avoided during pregnancy (this refers to a group of medications used to prevent breathing problems, often used for asthma, as well as chronic obstructive pulmonary disease or COPD, and allergies). The evidence base is poor and some (such as the anti-leukotriene drug montelukast) are excreted into the breast milk with unknown consequences to the baby
• Oral decongestants should be avoided during pregnancy, as these are generally not effective in treating rhinosinusitis and pose a risk of birth defects in the developing foetus. However, no studies directly assess these drugs in rhinosinusitis and pregnancy, and more research is needed
• Antihistamines and allergen immunotherapy (referring to any allergy medicines taken) again have a poor evidence base for the management of rhinosinusitis during pregnancy. These medications are generally not recommended for use during pregnancy. Recommendations are for immunotherapy to continue at the same dose where needed, but no new medication should be started during pregnancy. Over-the-counter medication pseudoephedrine is not recommended during pregnancy 
• Aspirin should be avoided during pregnancy, as it is associated with risks to the developing foetus. Aspirin belongs to a class of drugs called non-steroidal anti-inflammatory drugs (NSAIDs), and these should not be used during pregnancy 
• Paracetamol (also known as acetaminophen) is safe for use during pregnancy for pain, headaches, and fever
• Surgery that is a non-emergency should be avoided during pregnancy due to the inherent risks associated with surgery, such as infection and risks related to the use of general anaesthesia. If sinusitis is severe or complex, surgery (e.g., turbinate surgery, balloon sinuplasty) may be considered with local anaesthesia 

However, more robust research is needed with larger sample sizes, in all areas of medical intervention for pregnant women with sinusitis. 

Safe, alternative remedies

• Use of saline nasal rinses and sprays is considered safe during pregnancy⁷
• Keeping hydrated and using humidifiers are safe and can help moisten the air entering the nasal passages. Dry air is generally not good for the nose and sinus membranes, drying them out, stimulating mucus production, and attracting pathogens. Keeping the nasal passages moist is important 
• Steam inhalation from heated water in a large bowl (not directly from a steaming kettle) is a safe and effective technique for opening up the sinuses, thinning mucus, and helping to relieve pressure. A hot bath or shower are good alternatives. Eucalyptus in small quantities is considered safe during pregnancy and effective for sinusitis and could be added in. The use of essential oils during pregnancy should be discussed with a healthcare professional to ensure safety 
• Sleep will help strengthen the immune system to fight off the infection. Prop yourself up on a few pillows to help with breathing 
• Eat nutrient-rich food such as fruits and vegetables to support your immune system, even if your appetite has changed through pregnancy. Soups, warm drinks such as ginger tea (ginger is a natural anti-inflammatory agent), honey (a natural anti-septic), and some probiotic foods (like yoghurt) may help support the immune system and relieve sinusitis. However, any supplements should be checked with the doctor before they are used during pregnancy
• A warm compress can relieve sinus pressure, open up the blocked passageways, and help loosen mucus. A warm, damp cloth applied to the face can help soothe sinus pain 

Summary 

Sinusitis can be a debilitating condition causing pain, swelling, and tenderness. During pregnancy, the immune system adapts to the presence of the developing foetus, working to protect its wellbeing. The changing immune system, often from varying hormone levels, can mean the mother is more or less likely to catch certain illnesses. 

See a healthcare provider if:

• Symptoms worsen after improving
• Symptoms are severe (for example, you are experiencing a severe headache or facial pain)
• Symptoms do not improve after 10 days
• You experience multiple sinus infections
• You have an ongoing fever (over 4 days)

Sinusitis can occur more often during pregnancy but can be managed with some medications. Steam inhalation and saline nasal rinses are safe and effective alternative remedies for sinusitis. Eating a nutrient-dense diet and getting plenty of sleep can help strengthen the immune system to manage the condition better.