Pregnancy; the reproductive process through which a new baby is conceived, incubated and ultimately born into the world. Pregnancy is a unique, exciting time in a woman's life, as it highlights the woman's amazing creative powers. The growing fetus in the womb depends entirely on its mother's healthy body for all needs. Consequently, pregnant women must take steps to remain as healthy as they possibly can. There are so many changes going on in pregnant ladies and their mouth is no exception. Good oral hygiene is extremely important during pregnancy. Oral health and pregnancy effect each other, the increase of hormone levels can leave pregnant lady’s mouth more vulnerable to dental problems from bacteria and plaque & this in turn effect developing fetus adversely.

It should be the duty of health providers to educate pregnant women about the impact of good oral health on the well‐being of the mother and fetus. Prenatal oral health counseling is very important in informing the pregnant woman on the risks that poor oral health poses for the mother and fetus.

During pregnancy many complex physiologic changes occur in the women’s body, which can adversely affect oral health.

Effect on Periodontal Tissues:

Although the main cause that effects the health of periodontal tissues adversely is presence of bacteria in biofilms of dental plaque . But there are also secondary causes or factors that induce the oral changes and thus can adversely effect the periodontium , these can be certain medications like CCBs , smoking , medical conditions like diabetes , vitamins deficiency or hormonal changes like in pregnancy.

Several hormones, including the sex steroids, have an influence on the cellular components of the periodontal tissues and may interfere with the mechanisms involved in the pathology of periodontitis. Fluctuations in the levels of these hormones in physiologic or non-physiologic conditions may result in significant alterations in the periodontium, especially in the presence of preexisting plaque-induced gingival inflammation. Effects of these sex hormones (progesterone & estrogens) on the periodontium, include the following changes –

Involvement in vascular functions such as angiogenesis and vascular permeability: Higher estrogen levels in the body stimulate angiogenesis i.e formation of new blood vessels, while increased circulating progesterone levels increases capillary permeability and dilation, resulting in increased gingival exudate that may facilitate the recruitment of more inflammatory cells in the gingival area and the crevicular fluid. The enhanced vascular permeability may also be partly due to stimulating effects of progesterone on prostaglandin synthesis. 1

An effect of estrogen on salivary peroxidases: The salivary per-oxidases are the enzymes that are secreted in mammals through salivary glands or other mucosal glands which act as natural anti-bacterial & active against a variety of microorganisms. Elevated estrogen changes the redox potential of the salivary peroxidases thus affecting the action of salivary peroxidases. 2

Estrogen-mediated suppression: The increased level of estrogen in body leads in suppression of leukocytes production in the bone marrow and inhibition of polymorphonuclear leukocyte chemotaxis and phagocytosis. 3

Progesterone-induced reduction of the anti-inflammatory: effects of glucocorticoids, either directly via receptor binding on osteoblasts or indirectly by antagonizing glucocorticoid receptors. 4

Therefore, periods of hormonal flux during puberty, pregnancy, menopause or use of contraceptives have been associated with periodontal manifestations. These manifestations include –

Gingivitis & pregnancy tumor – Relationship between pregnancy and gingivitis confirmed the existence of a significant increase in gingivitis throughout pregnancy and between pregnant versus post-partum or non pregnant women.

Ehlers et al compared the dental evaluation and gingival crevicular fluid from 40 pregnant women and 40 age-matched nonpregnant control subjects. They found that 80% of pregnant women had gingival inflammation compared with 40% of control subjects.5

The interproximal papillae become red, edematous and tender to palpation, and they bleed easily if subjected to trauma. In some patients, the condition will progress locally to become a pyogenic granuloma or “pregnancy tumour,” which is most commonly seen on the labial surface of the papilla.

Tooth mobility – Mobility is highest during the last month of pregnancy. Increase of mobility during pregnancy was caused by alterations of the periodontal membrane and not because of the changes in the alveolar socket bone. The upper incisors are most mobile during the last month of pregnancy .6 During pregnancy the fibers and bone that support and hold the teeth in its socket can temporarily loosen causing the teeth to be slightly movable. This is usual a normal occurrence and will repair itself after pregnancy. Pregnancy associated gingivitis can also cause tooth mobility, as well as the more advanced periodontal disease.

Periodontitis – If gingivitis is not treated, it will progress into a more severe gingival disease called Periodontitis. Periodontitis can be associated with an infection of the gums and supporting bone of the teeth and can result in recession, tooth mobility, bone loss and bacteremia.

2. Tooth surface loss in pregnancy – Tooth surface loss, primarily through acid-induced erosion ,may be seen if there has been nausea and associated repeated vomiting during pregnancy. The palatal surfaces of the upper incisors and canines are often the most affected . The woman commonly presents complaining of sensitivity, which is a consequence of the resulting dentine exposure. These women should be advised to avoid tooth brushing directly after vomiting as the effect of erosion can be exacerbated by brushing an already demineralized tooth surface.7

3. Dental caries & pregnancy- Dental caries is a bacterial infection which is multifactorial in nature and caused by the bacterial fermentation of dietary sugars resulting in the localized destruction of the tooth. The important organisms in the initiation and progression of dental caries are the Streptococcus mutans , Lactobacilli and Actinomyces sp. Although pregnancy has no direct relation in the alteration of tooth structure.

The increased levels of Streptococcus mutans and Lactobacilli are found in late pregnancy and during lactation.8

4. Mucosal Changes in pregnancy – In pregnancy , due to increased level of the estrogen there is enhanced proliferation and desquamation of the oral mucosa.These desquamating cells enhance the microenvironment by providing nutrition and a suitable environment for bacterial growth, therefore potentially predisposing to caries. 9

5. Halitosis –

Pregnancy-induced nausea and vomiting due to morning sickness are experienced by 66% of pregnant women 10. Frequent vomiting leads to acidic environment in the mouth and this leads to demineralization of the teeth & makes the teeth more prone to food lodgment and decay, which results in halitosis. 11 Fetus in the womb absorbs calcium from the calcium deposits in the mother’s body. Insufficient calcium in the mother’s blood causes mineral to leach out from the bones and teeth & it may cause weaking of teeth that subsequently might results in cavities and decayed teeth causing bad breath. 12

Oral bacteria and bacterial byproducts can gain access to the fetoplacental unit via hematogenous spread, where they may produce inflammatory responses that could lead to adverse pregnancy outcomes.13 As described above the elevated levels of the sex hormones in pregnancy adversely affects the oral health , and in turn , the diseased periodontium or bad oral health may results in the bad outcomes in pregnancy. These risks in pregnancy related to bad oral health include the following.

It has been suggested that subclinical infections such as periodontitis can contribute to premature delivery and low birthweight as a result of pathogenic microorganisms or their microbial products, such as lipopolysaccharide (LPS), reaching the uterus via the bloodstream, inducing cytokine release in the decidua or the membranes, resulting in increased prostaglandin production or, indeed, uterine muscle contraction.14 Inflammatory mediators like cytokines and prostaglandins, when produced in the periodontal tissues in response to LPS stimulation, may also pose a real threat to the fetoplacental unit and increase the risk of preterm delivery and low birthweight.15

Proposed bio-mechanism of linking periodontal diseases to preterm-lowbirth weight delivery in Figure 1

According to traditional concepts, dental treatment of any kind has been avoided during the first trimester of pregnancy, so as not to harm the fetus during organogenesis. But nowadays , there is not enough evidence to ignore dental treatment even during the first trimester of pregnancy , emergency dental procedures are indicated at all times during pregnancy and can be performed during any trimester when a delay in necessary treatment could result in significant risk to the mother and an indirect risk to the fetus. 16 For elective dental procedures, the ideal period for complete dental treatment of a pregnant woman is the beginning of the second trimester. At this stage, there is no risk of teratogenesis, nausea and vomiting have subsided, and the uterus is not yet large enough to cause discomfort. However, it is important to remember that extensive reconstruction, crown and bridge as well as removable partial dentures should be deferred until after pregnancy.16

The major concern of administration of drug use in pregnancy is all about their safety to the developing fetus. To determine the risks associated with the use of drugs in pregnancy , US FDA has recommended different drug categories out of which category A & B are considered to be safe –

Drugs safe in pregnancy for the purpose of dental treatment or diagnosis 23, these are :

a. Local anesthetics – lignocaine is safe in pregnancy as it falls in category B

b. Analgesics – paracetamol category B , aspirin falls in c/d & it should be avoided in 3rd trimester , ibuprofen low dose & it should be avoided in 3rd trimester

c. Antibiotics – The safe antibiotics in dental prescribing are Amoxicillin & amoxicillin-clavulonate , azithromycin , cepahlosporins , erthyromycin (except estolate form).

d. Moutwashes – chlorohexidine moutwashes can be safely prescribed in pregnant ladies as they fall in category B according to US FDA.

Thus knowledge of drugs and their effects is also an important factor in safe prescribing of antibiotics, painkillers in dental practise.

From the above overall discussion we can conclude that the hormonal changes induced during pregnancy increases the risk of developing gum diseases, which in turn can be dangerous for the mother and can also impact the health of the baby. There should be done patient counselling by the physician or midwives prenatally or referral by them to dental professional to educate the patient about the two way interconnection of pregnancy and oral health. The patient should also be instructed about the proper brushing & flossing techniques and dietary instructions should also be given so that patient can maintain good oral environment during this crucial time period, and thus can prevent pregnancy complications that could arise from bad oral health.

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