From the Guidelines
Pregnant women can experience a bad taste in their mouth during pregnancy primarily due to hormonal changes, particularly increased estrogen levels, which can alter taste perception. This condition, known as dysgeusia, typically occurs during the first trimester but can persist throughout pregnancy. The hormonal fluctuations can cause a metallic, bitter, or sour taste that lingers even when not eating. Other contributing factors include increased sensitivity to certain foods, heightened sense of smell, acid reflux or heartburn which is common in pregnancy, and changes in oral health such as increased saliva production and gum inflammation, as noted in a recent study on pregnancy-related gastrointestinal and liver disease 1.
Some key points to consider:
- Heartburn, nausea, and vomiting are common during pregnancy, with frequency ranging from 30%–90%, and can contribute to a bad taste in the mouth 1.
- Nausea and vomiting of pregnancy (NVP) usually begins at 4–6 weeks, peaks at 8–12 weeks, and subsides by week 20, which may also impact taste perception 1.
- Diet and lifestyle modification are the initial steps in managing these symptoms in pregnancy, including reducing spicy, fatty, acidic, and fried foods, and eating small, frequent, and bland meals 1.
- Specific triggers, such as certain foods with strong odors or activities, should be identified and avoided to help manage symptoms and reduce the occurrence of a bad taste in the mouth 1.
To manage this symptom, pregnant women can try:
- Brushing teeth and tongue regularly
- Using alcohol-free mouthwash
- Staying hydrated
- Chewing sugar-free gum
- Eating small frequent meals
- Consuming citrus fruits or drinking lemon water which may temporarily mask the unpleasant taste. While dysgeusia is typically harmless and resolves after delivery, persistent severe symptoms should be discussed with a healthcare provider to rule out other conditions, as recommended by the American College of Obstetricians and Gynecologists (ACOG) 1.
From the Research
Changes in Taste During Pregnancy
- Pregnant women often report a change in taste, including an increased bitter or decreased sweet response 2.
- The majority of studies report either no change, or an increase in threshold/decrease in perceived taste intensity, particularly in the early stages of pregnancy, suggesting a possible decrease in taste acuity when pregnant 2.
- Physiological changes occurring during pregnancy, such as changes in weight and immune response, as well as circulating gonadal hormones, may influence taste signaling 2.
Gustatory Sense During Pregnancy
- A study of 97 pregnant women found that 90 (92.8%) reported some type of change in taste during pregnancy, usually a change in sour taste (59 women; 65.6%) 3.
- Pregnant women had higher gustatory thresholds than non-pregnant women, with a marked decrease in gustatory function noticed in the first trimester 3.
- The decrease in gustatory function during the first trimester is considered to be due to the notable changes in secretion of hormones that occur during this stage 3.
Hormonal Changes and Taste
- Salivary estrogen levels increased significantly during the second and third trimesters of pregnancy 4.
- Estrogen regulates the cellular functions of several tissues that may disturb the host response against bacteria, and high estrogen levels may contribute to the development of pregnancy gingivitis 4.
- Salivary measurements of estradiol and progesterone can be used as noninvasive methods for assessment of ovarian function, and may be related to changes in taste during pregnancy 5.