Abstract
Pregnancy rhinitis is a common condition that is not yet fully recognized by the public. This form of rhinitis affects approximately one in five pregnant women, can start in almost any gestational week, and disappears after delivery. However, as it reduces quality of life, and also possibly affects the fetus, treatment is often required. Saline irrigations, exercise and mechanical alar dilators are a safe and general means of relieving nasal congestion. Nasal corticosteroids have not been shown to be effective. As nasal decongestants provide good temporary relief, women tend to overuse them. Therefore, to avoid an additional rhinitis medicamentosa, nasal decongestants should be restricted to a few days use. Invasive methods of turbinate reduction may be effective, but are not recommended. The differential diagnosis towards sinusitis is often difficult. Antral irrigation is the ultimate diagnostic for purulent sinusitis and often needs to be repeated for therapeutic reasons. If β-lactam antibiotics are used, an increased dosage is required during pregnancy.
Pregnancy rhinitis has not, until recently, been recognized as a defined condition and taken seriously, even though nasal congestion due to pregnancy has been observed as a phenomenon for many years. A recent paper reports that snoring during pregnancy is very common and that it may have negative effects on the woman as well as on her fetus such as maternal hypertension, pre-eclampsia, intrauterine growth retardation and lower Apgar scores [1]. It is well known that nasal congestion is increased when the subject is in the supine position, especially in patients suffering from rhinitis [2]. Thus, as nasal congestion may result in snoring, pregnancy rhinitis may cause more serious complications than has earlier been suspected.
Air passing in through the nose is treated for the lungs; it is filtered for particles, tempered and humidified. Nasally inhaled air also transports nitric oxide (NO) from the sinonasal unit to the lungs allowing vasodilatation [3]. Nasal congestion may force the subject into mouth breathing, which lacks these functions. In allergic rhinitis, quality of life scores have been shown to be worse than in asthma, possibly influenced by problems such as day tiredness, thirst, poor concentration and headache [4]. This has not yet been evaluated in pregnancy rhinitis, but a parallel seems obvious.
In the last few decades, the awareness of rhinitis medicamentosa has increased. Women with pregnancy rhinitis tend to use nasal decongestants for prolonged periods of time, and are at risk of developing this additional condition [5].
Nasal congestion increases mouth breathing, which gives a dry mouth, and with less saliva the dental protection system against cavities is disturbed. Long-standing nasal congestion can also induce sinusitis.
This knowledge of the effects of nasal congestion is probably confined to ear, nose and throat (ENT)-oriented physicians, whilst pregnant women are mainly in contact with their obstetricians who may not be aware of the problem. A patient with a condition, such as pregnancy rhinitis, which concerns two specialties, is at risk of falling in between them. Research and information may help to close this gap.
Diagnosis
Several studies of the nasal congestion of pregnant women have investigated the phenomenon without stating a proper definition. A presumption has been that it is a condition that appears at the end of the first trimester and disappears after delivery [6,7]. In a study including a control group of nonpregnant women, unspecified subjective nasal congestion was significantly increased only during the third trimester [8]. In order to define pregnancy rhinitis we followed 23 women, who daily, until 1 month after delivery, scored nasal congestion and registered nasal peak expiratory flow (nPEF) [9]. The women were more congested during pregnancy than after, excluding days with other signs of respiratory tract infection (Figure 1). In cases where, by clinical experience, we were convinced that there was a congestion caused by pregnancy, a diagnosis was made. We then looked at the cases, and determined the criteria that would separate them from the rest of the women. This resulted in a clinical definition: ‘nasal congestion present during the last 6 or more weeks of pregnancy without other signs of respiratory tract infection and with no known allergic cause, disappearing completely within 2 weeks after delivery’. In addition, patients often suffer from a watery or a viscous, clear secretion. The swollen mucosa of the nasal turbinates responds to local decongestion, which makes further inspection of the nasal cavities possible (Figure 2).
Nasal congestion during pregnancy was reduced after delivery.
Endoscopic appearance of the right inferior turbinate in pregnancy rhinitis before (A) and after (B) decongestion.
In our study, the group of pregnancy rhinitics had no change in nasal mucociliary transport speed which was however, found to be significantly decreased during pregnancy in the group of women without the condition [10]. A similar [11], and a reverse [12] physiologic change have been reported. Further studies on larger populations are needed to confirm the findings and understand the mechanisms responsible, including the biologic functions of the changes. Measurement of mucociliary transport speed is of no diagnostic value.
Objective measurements of nasal congestion can also be used in studies, but are not needed for a clinical diagnosis. Our diagnostic criteria for pregnancy rhinitis include the natural course after delivery, in order to make studies on etiology and epidemiology possible. However, in clinical practice the diagnosis is made for a pregnant woman with nasal congestion not due to any other condition.
Differential diagnosis
In pregnancy, sinusitis may give nasal congestion as the only symptom [13]. Even in nonpregnant individuals, sinusitis is often a difficult diagnosis to make, and the presence of nasal congestion is of no help in that respect. Purulent secretion in the middle meatus, sensation of foul smell, unilateral predominance of purulent discharge and unilateral predominance of local pain, have been suggested as strong diagnostic signs for sinusitis [14], but it may not be as simple as that; especially not in primary care [15]. Decongestion facilitates nose inspection, which is best performed with an endoscope, but anterior rhinoscopy is also useful. Ultrasound examination of the sinuses could be an additional tool in experienced hands. In exceptional cases, x-ray may be required, taking care not to expose the fetus. However, antral puncture is the ultimate diagnostic method for sinus empyema.
Airborne allergies can cause nasal congestion, often combined with watery secretion and sneezing, which is not the case in pregnancy rhinitis. Allergic rhinitis due to house dust mites, however, frequently presents with nasal congestion as the sole symptom, and if it appears during pregnancy for the first time, it is difficult to differentiate from pregnancy rhinitis, particularly as the two forms may coexist. Allergy is excluded by relevant tests for specific immunoglobulin (Ig)E.
Rhinitis medicamentosa is a differential diagnosis as well as a complication of pregnancy rhinitis. As most patients do not spontaneously mention their long-standing use of nasal decongestants, it is important to stress that question. If the nasal congestion persists when the use of decongestants has been given up, it is no longer caused by rhinitis medicamentosa. In healthy people with induced rhinitis medicamentosa, the congestion disappears within 2 days after the use of decongestants has ceased [16]. But, to be sure, 1 week seems more appropriate in pregnancy.
Nasal granuloma gravidarum (pregnancy tumor, pregnancy granuloma or telangiectatic polyp) is a benign, rapidly growing tumor, which causes nasal obstruction. The histology is practically the same as in pyogenic granuloma. In contrast to pregnancy rhinitis, it is almost always unilateral and tends to cause recurrent nose-bleed. Inspection of the nasal cavity reveals a lesion, which is well vascularized, and bleeds easily on touch. It may even protrude, and occupy the nasal vestibulum to be readily seen from the outside. Excision under local anesthesia is indicated if nasal obstruction or nose-bleeds are troublesome, but there is a likelihood of spontaneous regression after delivery [17].
Possible influence on the fetus
Effects of pregnancy rhinitis upon the fetus seem to be connected with the mother's sleep. It has long been known that nasal congestion increases when the subject is in the supine position, especially in patients suffering from rhinitis [2]. Difficulty in breathing through the nose increases the tendency to revert to mouth breathing and snoring. Regular snoring was reported in 9% of 73,231 women and was shown to be associated with hypertension, independent of body mass index [18]. In a questionnaire study of 502 women conducted the day after delivery, habitual snoring the previous week was reported in 23% [1]. Snorers had a significantly higher frequency of hypertension, pre-eclampsia and intrauterine growth retardation, and the Apgar scores of their babies were lower.
In the maxillary sinuses, production of NO is the main source of nasal NO, which, when inhaled, reduces pulmonary vascular resistance, and increases pulmonary oxygenation [19].
There is a possibility that mouth breathing, due to pregnancy rhinitis, may affect pulmonary vascular tone and/or oxygenation and, potentially, the oxygen supply to the fetus. This could be a mechanism behind the complications associated with snoring as described above.
Furthermore, there is a risk that pregnancy rhinitis induces sleep apnea in women who are predisposed to that disease, but who can normally breathe through the nose.
Treatment
Education of pregnant women
If women know that pregnancy can induce nasal congestion and are informed of the treatment options, they presumably handle it better if it appears. Patients are comforted to hear that their nasal congestion is a common, self-limiting experience, shared by generations of women, noted in ancient writings, and described since the beginning of modern scientific literature. As suggested by Rambur [20], all pregnant women should be informed of pregnancy rhinitis on their first antenatal visit. This pedagogic task naturally implies an educational effort towards the antenatal staff, to ensure that it does not cause anxiety instead of comfort.
Physiologic measures
To raise the head end of the bed sufficiently is a simple measure to reduce nasal congestion and patients may need to be reminded of it. The angle needed would be 30° [2], or 45° [21]. It is probably easier to tolerate ‘books under the legs of the head end of the bed’ than extra pillows, especially in pregnancy, when the side position is desired both because of vena cava syndrome, and because it reduces the risk of snoring.
Physical exercise has a well-known decongesting effect on the nasal mucosa [22] and may have an additional effect on sleep disturbance due to nasal congestion; the normal fatigue and well-being following exercise may help the woman to sleep.
The narrowest part of the airway is the nasal valve region, which can be widened by mechanical devices. An internal nasal dilator significantly reduced snoring in men [23] and was as effective as a local decongestant in healthy subjects [24]. An external nasal dilator improved subjective nasal breathing in 24 patients with ‘pregnancy-related nocturnal nasal congestion’ [25]. As these devices have no side effects they are well worth trying, especially when nasal congestion disturbs sleep.
Nasal saline washings
Nasal washings with a solution of 5 ml of salt in 0.5 l of water are, in my clinical experience, helpful for many women with pregnancy rhinitis, as well as in other sorts of rhinitis. The patient is instructed to prepare it at home, and to lean forward when taking it through the nose. She can choose to just sniff it in from a cupped hand, or to use any of the various products available to make the administration more comfortable. The saline washing produces temporary relief, reduces the amount of secretions and removes crusts, which impair the nasal airway. There are no restrictions as to how often it may be performed.
Nasal decongestants
Women with pregnancy rhinitis tend to overuse nasal decongestants, as they give good temporary relief. This results in an even more troublesome situation due to rhinitis medicamentosa, with rebound swelling, hyper-reactivity and tolerance, which does not resolve after delivery. The patient gets used to the decongested state as being normal, and needs to be informed about the situation [5]. Even a dosage given only in the evenings, to healthy subjects, resulted in rhinitis medicamentosa [26]. For this reason, nasal decongestants should only be used temporarily. Some authors recommend that, during pregnancy, nasal decongestants should not be used for more than 5 [27] or even 3 [28] days.
Oral decongestants
Vasoconstrictors administered orally, such as pseudoephedrine and phenylpropanolamine, are widely used in various sorts of rhinitis [29]. No data are available on whether they are efficient or not in pregnancy rhinitis. Recommendations for their use during pregnancy on the whole vary between countries; for example, phenylpropanolamine is classified to be safe for use during pregnancy in Sweden, whereas pseudoephedrine is preferred in US guidelines [29]. Earlier reports of an increased risk of gastroschisis in the fetus could not be confirmed in a larger study of 206 cases compared with 798 controls [30]. However, as in nonpregnant women, there is a risk of systemic adverse effects, including elevated blood pressure, palpitations, loss of appetite, tremor and sleep disturbance.
Systemic corticosteroids
Corticosteroids have been administered systemically for various nasal conditions, but prolonged or repeated use should generally be avoided to prevent adrenal suppression or other systemic side effects. The only published paper found that deals with such treatment for rhinitis due to pregnancy is Mabry's description of his experiences with the ‘gradual but sustained congestion of the nasal mucosa, usually developing toward the end of the first trimester of pregnancy’ [6]. In his opinion, short courses (≤2 weeks) of oral corticosteroids may give temporary relief allowing withdrawal of nasal vasoconstrictors, and intranasal submucosal injections of corticosteroids give effect within a few hours, which lasts for 4–6 weeks. No studies of these treatments have been carried out, and the risk of side effects affecting the fetus and the pregnant woman is obvious, including blindness after intranasal injections.
Nasal corticosteroids
Nasal corticosteroids are effective in allergic rhinitis [31,32], nasal polyps [33], rhinitis medicamentosa [34], and perennial, nonallergic rhinitis [35]. However, pregnant patients were never included in any of these studies.
Nasal spray of fluticasone propionate did not show any effect on pregnancy rhinitis in 53 women treated for 8 weeks in a placebo-controlled, randomized, double-blind study with parallel groups, as evaluated by daily symptom scores and nPEF, as well as acoustic rhinometry before and after treatment [36]. Neither was there any detectable influence on maternal morning S-cortisol and overnight 12-h-U-cortisol, nor any difference in ultrasound measures of fetal growth, or in pregnancy outcome.
Congenital malformations were studied in 2014 infants whose mothers had used inhaled budesonide for asthma in early pregnancy [37]. Using the Swedish Medical Birth Registry, no increase in the rate of congenital malformations was observed compared with the general population rate. Thus, it could probably also be safely used in this respect when inhaled nasally for rhinitis during pregnancy.
Surgery
Invasive methods such as electrocautery, cryo-therapy, laser or radiofrequency, used to reduce mucosal swelling of the inferior turbinates in pregnancy rhinitis, are discussed by Rambur [20]. Each method has its advantages, as have different types of surgical reduction. The effect may be temporary or permanent and the frequency, degree, and duration of side effects such as crusting, edema and bleeding, varies [38]. The tendency of pregnancy rhinitis to heal spontaneously after a limited period of time has to be borne in mind. These methods should be carefully considered in desperate cases only, for example in a woman with pregnancy rhinitis and sleep apnea if other sorts of treatment of the nose fail, and continuous positive airway pressure is not tolerated.
Antibiotics
Antibiotics are not indicated in pregnancy rhinitis. However, it is important to treat sinusitis intensively. Repeated antral irrigations are often needed, when the sinusitis has been longstanding before diagnosis. Due to local tradition, this way of treating sinusitis may be underused. The dosage of β-lactam antibiotics needs to be elevated by 50%, due to increased renal clearance during pregnancy [39]. An extra dose per day is recommended, in order to increase the time over the minimum inhibitory concentration.
Historic knowledge
Several scientific papers published in the late 19th century presented observations connecting the genital organs with the nose. In a case report from 1881, Bresgen described a woman with ozaena, which worsened during menstruation [40]. In 1884, MacKenzie quoted the Ayurvéda, Hippocrates and Celsus, and quite a few 19th century writers, and he presented multiple observations of his own, among others on ‘the erection of the nasal turbinated structures’ during menstruation, and worsening of nasal symptoms during menstruation or sexual excitement [41]. He expanded his theories, and included nasal congestion during pregnancy, ‘at periods corresponding to those of the menstrual flow’ [42]. Endriss also described epistaxis and worsening of nasal disease due to menstruation [43].
After these publications, interest seems to have faded until 1943, when Mohun presented 20 cases of ‘vasomotor rhinitis’ during pregnancy; appearing in the 3rd to 7th month of gestation, persisting to term, all but one normalizing within 10 days post partum [44]. He concluded that there was a connection with estrogen, but also that ‘the acromegaly of pregnancy may in some way predispose the nasal structure to vasomotor rhinitis’.
Estrogen was suggested to influence the nasal mucosa, as there were case reports of success with nasal application of estrogen in the treatment of atropic rhinitis [45,46].
In a 1950 summary, Holmes and colleagues, referring to the predecessors above, stated that ‘the occurrence of hyperemia with swelling and hypersecretion in the nose as an accompaniment of menstruation does not require further confirmation’ and emphasized the influence of psychologic factors on the pathogenesis of those symptoms in menstruation as well as in pregnancy [47].
Etiology
Nasal mucosal swelling can be caused by a decrease in the α-adrenergic tonus to the venous sinusoids giving increased vascular pooling of blood. Another mechanism is leakage of plasma from the vascular bed into the stroma of the mucosa, giving edema. No hormone is known to activate any of these pathways in the nasal mucosa.
Estrogen
The theory that raised levels of estrogen cause nasal congestion in pregnancy is based mainly on the results of Toppozada and colleagues from biopsy studies on nasal mucosa in pregnancy [7] and from women taking contraceptive pills [48], although a similar study during the menstrual cycle failed to show any cyclic changes [49]. The early high-estrogen contraceptive pills produced nasal congestion as a side effect.
If estrogen causes nasal obstruction there should be a relative congestion during the preovulatory and luteal phases of the menstrual cycle, when the serum levels of estrogen are highest. However, in a study of 41 normally menstruating women, we found significantly more congestion during the menstrual phase, when the estrogen levels are lowest [50]. Furthermore, serum levels of estradiol measured four times during pregnancy in 23 women were not shown to be more elevated in women with pregnancy rhinitis than in women without [51].
If estrogen causes nasal obstruction there should also be increasing congestion in every pregnant woman. The mean results of different measurements indicate rising congestion during pregnancy [12], but some individuals react differently. Only 8 out of 23 pregnant women had increasing congestion and nine individuals, surprisingly, registered declining congestion during the course of pregnancy [9]. A parallel is obvious: approximately a third of asthmatics improve during pregnancy, whereas a third deteriorate [52]. Even though reports of the exact proportions are still extremely variable (0–69% and 0–44%, respectively), influenced by the different ways asthma severity was assessed and the variable severity of disease in the groups that were studied, the existence of this variation in pregnant asthmatics seems indisputable. The largest cohort studied (568 patients) confirmed these figures and also showed a significant relationship between self-reported change in asthma course during pregnancy and that of rhinitis [53]. However, this is not surprising as there is a widely accepted connection between asthma and rhinitis in general: the concept of the ‘united airways’ [54], where upper and lower airway inflammatory events influence each other, being part of a systemic condition with variable manifestations.
Placental growth hormone
After the first trimester of pregnancy the episodic bursts of human growth hormone (hGH) are replaced by a continuous secretion, with rising values of a placental growth hormone variant (PGH) [55]. In our study, serum levels of PGH were significantly higher in the pregnancy rhinitis group throughout pregnancy [51].
A ‘hormonal rhinitis’ has been proposed to occur in acromegaly [56]. Skinner and Richards support the theory that hGH may induce changes in the mucosa of the upper airways [57]. They found an increased frequency of mucosal hypertrophy and polyps in the sinuses of acromegalic patients compared with patients with prolactinoma. No such pathology was found in the nasal mucosa, which was, however, examined after preoperative cocaine treatment. We believe that PGH may stimulate mucosal growth in a similar way and thereby induce pregnancy rhinitis.
Progesterone
Serum levels of progesterone were similar in pregnant women with or without pregnancy rhinitis [51]. This does not support the mechanism proposed by Schatz and Zeiger of increased circulating blood volume, possibly enhanced by the vasodilating effect of progesterone, being responsible for pregnancy-induced nasal congestion [58]. Although no quantitative confirmation of this vascular pooling exists, they do consider it an apparent cause [27].
Incidence
As the few earlier reports on incidence comprise small numbers of women (30% in 79 women [6], 18% in 66 women [59], and 21% in 160 women [25]) we conducted a questionnaire study on 810 women. Subjective nasal congestion was registered upon all visits during and after pregnancy in 599 of the women (74% response rate) [60]. The incidence of pregnancy rhinitis was 22%. It manifested itself in gestational weeks 7 through 36; in other words, from as early as it was possible for it to be registered, until as late as possible to obtain a 6-week duration (Figure 3). By excluding women with longstanding nasal problems before conception, the incidence of pregnancy rhinitis may have been underestimated, but as their symptoms may have varied over time when they were not pregnant, it was too difficult to evaluate what impact pregnancy may have had.
Pregnancy rhinitis appeared at any time during gestation in the 133 women§.
In another study of 2264 Swedish pregnant women on visits in gestational weeks 12, 20, 30 and 36, a positive answer to the question of ‘daily nasal stuffiness during the last 3 weeks’ on any of the visits placed those women into the ‘stuffiness’ group [61]. In week 36, the rate was 42%. Out of 1546 women who answered on all four occasions, 11% reported stuffiness every time. These figures include all types of rhinitis.
One study fails to show any significantly increased frequency of nasal congestion during pregnancy [62]. A totale of 27 nonpregnant and 33 pregnant women were asked, once in each trimester, to score nasal congestion on a visual analog scale (VAS) and the ‘prevalence of congestion’ was compared. The cutoff level on the scale that was used to define congestion was not specified in the paper. The resulting 33, 61, 55 and 55%, respectively, was not significantly different, despite the ‘congestion’ in pregnancy being almost twice as frequent as in the controls. This method, with interindividual comparison of VAS values, is most certainly not appropriate for such a small number of women, but no power calculation was presented in this paper.
Risk factors
Smoking
The incidence of pregnancy rhinitis in our questionnaire study was significantly higher in smokers than in nonsmokers (odds ratio: 1.7; 95% confidence interval: 1.1–2.5) [63]. It is possible that smoking, as an irritant, adds to other changes in some women and thus produces nasal congestion.
Allergy
The electron-microscopic findings of the nasal mucosa from pregnant women with nasal symptoms were identical to those in allergic rhinitis, reported Toppozada and colleagues [7]. Mabry found no connection between anamnestically constant or frequent nasal congestion in pregnancy and previously documented allergic rhinitis [59].
In our questionnaire study the proposed risk factors asthma, hay fever and month of conception were not associated with the incidence of pregnancy rhinitis [60]. In a study of 165 of those women, 83 of whom had experienced pregnancy rhinitis, in vitro tests for ten airborne allergens were performed [63]. The overall sensitization was not raised in the group of women who had experienced pregnancy rhinitis compared with the group of women who had not. However, sensitization to house dust mites was more frequent in the former group. Thus, it seems that the few women who have high levels of IgE against house dust mites are more likely to experience pregnancy rhinitis. It is impossible to separate their pregnancy rhinitis from a subclinical allergic rhinitis with deterioration during pregnancy, but they all clearly recovered after delivery, indicating a pregnancy-related reaction.
Serum levels of soluble intercellular adhesion molecule (sICAM)-1 have been shown to be elevated in perennial [64], and seasonal allergic rhinitis [65], and can thus be used as a marker of allergic nasal disease. In a study on 23 pregnant women, the group of women with pregnancy rhinitis had similar mean serum values of sICAM-1 as the group without the diagnosis and the values did not change significantly over time [63].
Hyper-reactivity
To differentiate hyper-reactive subjects from controls using rhinostereometry, a limit of 0.4 mm ipsilateral congestion, 5 min after provocation with histamine 2 mg/ml has been proposed [66]. We compared 12 women who had experienced pregnancy rhinitis in this respect, with 13 who had not [63]. There was no difference between the two groups regarding the number of women exceeding that limit. Neither was any difference found between the groups regarding their reactions to increasing concentrations of histamine, as measured by rhinostereometry or acoustic rhinometry.
Conclusion
Pregnancy rhinitis has evolved as a defined clinical entity that commonly occurs. It can occur at almost any time during pregnancy, and it disappears after delivery. As far as we know, it is not caused by any single factor. Placental growth hormone seems to be the hormone involved, rather than estrogen or progesterone. Smoking and sensitization to house dust mites may also play a role. Nasal congestion may be considered a trivial problem, but quality of life studies rank it highly. Furthermore, it increases the risk of snoring, which has been suggested to have negative effects on the fetus. Therefore, it is important that pregnant women are informed about pregnancy rhinitis and how to manage it. There is no cure, but simple measures such as physical exercise, elevating the head end of the bed, nasal alar dilators and nasal saline washings can improve nasal breathing. Nasal decongestants should be avoided for prolonged periods of time, as their use induces rhinitis medicamentosa. If the patient has difficulty discontinuing use of nasal decongestants, nasal corticosteroids could be effective, but they have not been shown to be effective in isolated pregnancy rhinitis. Systemic corticosteroids and oral decongestants should not be used. Sinusitis is a differential diagnosis, which needs to be borne in mind, and which can be difficult to exclude without an antral puncture.
Executive summary
Pregnancy rhinitis is defined as nasal congestion present during the last 6 or more weeks of pregnancy without other signs of respiratory tract infection and with no known allergic cause, disappearing completely within 2 weeks of delivery.
These criteria include the natural course after delivery, in order to make studies on etiology and epidemiology possible. However, in clinical practice the diagnosis is made once a pregnant woman makes a consultation with nasal congestion not due to any other condition.
Sinusitis, allergy and rhinitis medicamentosa are common diagnoses, which should be excluded. A thorough patient history and inspection of the nose is the minimum of investigation.
Snoring during pregnancy may give hypertension, pre-eclampsia, intrauterine growth retardation and lower Apgar scores.
There is a theory that mouth breathing, due to pregnancy rhinitis, may affect pulmonary vascular tone and/or oxygenation and possibly also the oxygen supply to the fetus.
Furthermore, there is a risk that pregnancy rhinitis induces sleep apnea in women who are predisposed to that disease.
All pregnant women should be informed about pregnancy rhinitis.
Simple measures such as physical exercise, elevated head end of the bed, nasal alar dilators and nasal saline washings can improve nasal breathing.
Nasal decongestants should be avoided for prolonged periods of time, as they induce rhinitis medicamentosa. If the patient finds it difficult to stop the use of nasal decongestants, nasal corticosteroids can be effective, but they have not been shown to be effective in isolated pregnancy rhinitis.
Systemic corticosteroids and oral decongestants should not be used.
Even though nasal congestion due to pregnancy has been noted in ancient writings and has been described since the beginning of modern scientific literature, our knowledge is limited.
Placental growth hormone seems to be the hormone involved, rather than estrogen or progesterone.
Pregnancy rhinitis affects about one in five pregnant women.
It can occur at almost any gestational week.
Smoking and sensitization to house dust mites are risk factors for pregnancy rhinitis, whereas asthma, hay fever, month of conception and hyper-reactive nasal mucosa are not.
Future perspective
Scientific activity concerning pregnancy rhinitis has not been overwhelming in the past. As our definition made it possible for us to carry out further studies on the subject, it may hopefully inspire others, too. At present, delivery is the only known cure and more knowledge on the mechanisms behind the condition is needed to find another. I believe that the results from studies on nasal breathing, snoring and pregnancy complications will stimulate us to find it in the near future. Until then, there is a rewarding educational task to deliver the present knowledge to antenatal, primary care and ENT staff, as well as to the public.