**1. Introduction**

Periodontitis has prevailed in human history from the dawn of civilization and still is a major cause of tooth loss in adult population. The etiology of periodontal disease (PD) is complex in nature, and it is a multifactorial disease, which is largely influenced by genetic, environmental, and microbial factors [1]. The periodontal disease begins at the gingiva and progress downwards and affects the tooth-supporting structures, i.e., periodontal ligament, cementum of the root, and alveolar bone. The clinical features of periodontitis are bleeding from the gums, pus discharge, dull gnawing pain, bad breath, mobility of teeth, pathological tooth migration, gingival recession, and exfoliation of teeth in severe cases.

Periodontal disease results from a complex interplay between the subgingival biofilm and the host immune inflammatory event, which develop in the gingival and periodontal tissues in response to the challenge presented by the bacteria [2]. The bacteria may initiate the disease, but the progression is host immune-mediated, and several inflammatory cells and enzymes are released which have a detrimental effect on other cells, tissues, and organ systems. There is a shift from healthy nonpathogenic flora to a huge virulent and infectious anaerobic flora in the periodontal disease. These bacteria and their toxins and various pro-inflammatory mediators penetrate into systemic circulation. The penetration of bacterial toxins and host-mediated immunomodulatory mediators into systemic circulation can have a toxic effect on the cells and organs elsewhere in the body. Environmental, physical, social, and host stresses may affect and modify disease expression through a multitude of pathways.

Systemic diseases tend to increase the periodontitis progression and can complicate the treatment of periodontal diseases. Periodontal infection may significantly enhance the risk for certain systemic diseases or alter the natural course of systemic conditions. There is a two-way relationship between periodontal disease and systemic disease or condition in an individual. The influence of periodontal infection on systemic disease and condition documented includes coronary heart disease (CHD) and CHD-related events such as angina, infarction, atherosclerosis, and other vascular conditions; stroke; diabetes mellitus; preterm labor, low birth weight delivery, and preeclampsia; and respiratory conditions such as chronic obstructive pulmonary disease [3].

Adverse pregnancy outcomes have been attributed to infections and inflammatory conditions in the vagina and elsewhere in the body. The potential role of chronic bacterial infections elsewhere in the body remote from the fetal-placental unit, which may influence the health and growth of babies in the placenta, has been studied immensely. This realization that infection in any part of the body can affect the placenta has led to the idea that periodontal disease can be a possibility in adverse pregnancy outcome. Local elevation of pro-inflammatory prostaglandins and cytokines due to "chronic gram-negative infection" in the periodontal diseases can be a risk factor [4]. Periodontal diseases have shown to increase the systemic levels of some of these inflammatory mediators [5]. Periodontal disease has a possibility to influence pregnancy outcome through an indirect mechanism, involving inflammatory mediators or a direct bacterial assault on the amnion and causing preterm low birth weight babies (PLBW). This chapter highlights the bi-directional relationship between pregnancy, pregnancy outcome, and periodontal disease.

#### **1.1 Focal infection theory revisited**

William Hunter, a British physician in 1900, first developed the idea that oral microorganisms were responsible for a wide range of systemic conditions that were not easily recognized as being infectious in nature. Hunter also identified gingivitis and periodontitis as foci of infection and advocated the extraction of teeth with these conditions to eliminate source of sepsis. He also thought that oral organisms had specific actions on different tissues and that these organisms were acted by producing toxins, thereby resulting in low-grade superinfection that produce systemic effect over prolonged periods. The Hunter theory became widely accepted, thereby leading to wholesale extraction of teeth. The focal infection theory fell into disrepute during the 1940s and 1950s when widespread extraction failed to reduce or eliminate the systemic conditions. However, Hunter ideas did encourage extensive research in the areas of microbiology and immunology. The Hunter theories are being revived today in light of recent research demonstrating links between oral and systemic health. Today's era of evidence-based medicine and dentistry provides an excellent environment in which to examine the possible relationship between oral infection and systemic disorders.

**19**

*Periodontal Disease and Pregnancy Outcome DOI: http://dx.doi.org/10.5772/intechopen.84949*

with normal birth weight infants [7].

**1.2 Pregnancy and its outcome**

resultant clinical picture.

and low birth weight babies.

affect the liver, kidneys, brain, and the clotting system.

tions with highest risk of adverse pregnancy outcomes.

disabilities, and various developmental defects.

The first association between periodontal disease and preterm low birth weight babies was documented by Offenbacher and colleagues in 1996 using a case-control study design. The study by Offenbacher et al. [6] suggested that maternal periodontal disease could lead to a sevenfold increased risk of delivery of a preterm low birth weight infant. Human case-control studies have demonstrated that women who have low birth weight infants as a consequence of either preterm labor or premature rupture of membranes tend to have more severe periodontal disease than mothers

Every pregnant woman who is carrying a live baby in her womb wishes to deliver a healthy baby. There are numerous genetic, pathological, and environmental factors that can affect the growth and development of the baby in the womb. During the course of a normal pregnancy, a series of profound and dynamic physiological changes occur in both the mother and developing baby [8]. Pregnancy and parturition involve a complex series of molecular and biological events for mother and fetus. Pregnancy by itself does not cause periodontal diseases, but the hormonal changes during pregnancy accentuate the gingival response to plaque and modify

Medical science aims at reducing the risk factors involved in the growth and development of a baby in the womb. Adverse pregnancy outcomes including preeclampsia, preterm delivery, intrauterine growth restriction, and fetal demise affect a significant number of pregnancies and are a major source of both maternal and neonatal morbidity and mortality. The Centers for Disease Control and Prevention (CDC) advocates that babies born with less than 5.5 pounds or 2.5 kg will be at risk of long-term health problems such as delayed motor skills, social growth, or learning disabilities. Babies born, at least 3 weeks, earlier than its due date have also risk for retarded growth and development [9]. Respiratory problems, vision and hearing loss, or feeding and digestive problems are other problems associated with preterm

Adverse pregnancy outcomes (APOs) are serious events that every year cause the death or disability of many newly born infants worldwide [10]. The most common adverse pregnancy outcomes are represented by low birth weight (LBW), preterm birth (PTB), and preeclampsia (PE). Adverse pregnancy outcomes represent an important health issue which affects not only the infant but also the mother, and more than half a million women die each year from related causes. About 10–15% of maternal death during pregnancy is associated with PE and eclampsia, which could

World Health Organization (WHO) in 1995 defined low birth weight (LBW) as any live birth of <2500 g and very low birth weight to be <1500 g. WHO defines preterm birth as any live birth at <37 weeks of gestation period [11, 12]. More than 33% of the infant mortality is attributed to the preterm low birth weight (PTLW), and surviving infants also have increased morbidity to congenital, neurological

Little reduction in incidence of adverse pregnancy outcomes has occurred despite advances in technology, promotion of prenatal care, and continued scientific efforts. Investigations to detect the potential causative factors for adverse pregnancy outcome include infection and/or inflammation in the reproductive tract and at sites remote from the feto-placental unit. The relationship between adverse pregnancy outcomes and maternal periodontal infections has been studied extensively over the past 10 years, as periodontal infection is most prevalent in popula-

#### *Periodontal Disease and Pregnancy Outcome DOI: http://dx.doi.org/10.5772/intechopen.84949*

*Gingival Disease - A Professional Approach for Treatment and Prevention*

a multitude of pathways.

pulmonary disease [3].

outcome, and periodontal disease.

**1.1 Focal infection theory revisited**

oral infection and systemic disorders.

and several inflammatory cells and enzymes are released which have a detrimental effect on other cells, tissues, and organ systems. There is a shift from healthy nonpathogenic flora to a huge virulent and infectious anaerobic flora in the periodontal disease. These bacteria and their toxins and various pro-inflammatory mediators penetrate into systemic circulation. The penetration of bacterial toxins and host-mediated immunomodulatory mediators into systemic circulation can have a toxic effect on the cells and organs elsewhere in the body. Environmental, physical, social, and host stresses may affect and modify disease expression through

Systemic diseases tend to increase the periodontitis progression and can complicate the treatment of periodontal diseases. Periodontal infection may significantly enhance the risk for certain systemic diseases or alter the natural course of systemic conditions. There is a two-way relationship between periodontal disease and systemic disease or condition in an individual. The influence of periodontal infection on systemic disease and condition documented includes coronary heart disease (CHD) and CHD-related events such as angina, infarction, atherosclerosis, and other vascular conditions; stroke; diabetes mellitus; preterm labor, low birth weight delivery, and preeclampsia; and respiratory conditions such as chronic obstructive

Adverse pregnancy outcomes have been attributed to infections and inflammatory conditions in the vagina and elsewhere in the body. The potential role of chronic bacterial infections elsewhere in the body remote from the fetal-placental unit, which may influence the health and growth of babies in the placenta, has been studied immensely. This realization that infection in any part of the body can affect the placenta has led to the idea that periodontal disease can be a possibility in adverse pregnancy outcome. Local elevation of pro-inflammatory prostaglandins and cytokines due to "chronic gram-negative infection" in the periodontal diseases can be a risk factor [4]. Periodontal diseases have shown to increase the systemic levels of some of these inflammatory mediators [5]. Periodontal disease has a possibility to influence pregnancy outcome through an indirect mechanism, involving inflammatory mediators or a direct bacterial assault on the amnion and causing preterm low birth weight babies (PLBW). This chapter highlights the bi-directional relationship between pregnancy, pregnancy

William Hunter, a British physician in 1900, first developed the idea that oral microorganisms were responsible for a wide range of systemic conditions that were not easily recognized as being infectious in nature. Hunter also identified gingivitis and periodontitis as foci of infection and advocated the extraction of teeth with these conditions to eliminate source of sepsis. He also thought that oral organisms had specific actions on different tissues and that these organisms were acted by producing toxins, thereby resulting in low-grade superinfection that produce systemic effect over prolonged periods. The Hunter theory became widely accepted, thereby leading to wholesale extraction of teeth. The focal infection theory fell into disrepute during the 1940s and 1950s when widespread extraction failed to reduce or eliminate the systemic conditions. However, Hunter ideas did encourage extensive research in the areas of microbiology and immunology. The Hunter theories are being revived today in light of recent research demonstrating links between oral and systemic health. Today's era of evidence-based medicine and dentistry provides an excellent environment in which to examine the possible relationship between

**18**

The first association between periodontal disease and preterm low birth weight babies was documented by Offenbacher and colleagues in 1996 using a case-control study design. The study by Offenbacher et al. [6] suggested that maternal periodontal disease could lead to a sevenfold increased risk of delivery of a preterm low birth weight infant. Human case-control studies have demonstrated that women who have low birth weight infants as a consequence of either preterm labor or premature rupture of membranes tend to have more severe periodontal disease than mothers with normal birth weight infants [7].

#### **1.2 Pregnancy and its outcome**

Every pregnant woman who is carrying a live baby in her womb wishes to deliver a healthy baby. There are numerous genetic, pathological, and environmental factors that can affect the growth and development of the baby in the womb. During the course of a normal pregnancy, a series of profound and dynamic physiological changes occur in both the mother and developing baby [8]. Pregnancy and parturition involve a complex series of molecular and biological events for mother and fetus. Pregnancy by itself does not cause periodontal diseases, but the hormonal changes during pregnancy accentuate the gingival response to plaque and modify resultant clinical picture.

Medical science aims at reducing the risk factors involved in the growth and development of a baby in the womb. Adverse pregnancy outcomes including preeclampsia, preterm delivery, intrauterine growth restriction, and fetal demise affect a significant number of pregnancies and are a major source of both maternal and neonatal morbidity and mortality. The Centers for Disease Control and Prevention (CDC) advocates that babies born with less than 5.5 pounds or 2.5 kg will be at risk of long-term health problems such as delayed motor skills, social growth, or learning disabilities. Babies born, at least 3 weeks, earlier than its due date have also risk for retarded growth and development [9]. Respiratory problems, vision and hearing loss, or feeding and digestive problems are other problems associated with preterm and low birth weight babies.

Adverse pregnancy outcomes (APOs) are serious events that every year cause the death or disability of many newly born infants worldwide [10]. The most common adverse pregnancy outcomes are represented by low birth weight (LBW), preterm birth (PTB), and preeclampsia (PE). Adverse pregnancy outcomes represent an important health issue which affects not only the infant but also the mother, and more than half a million women die each year from related causes. About 10–15% of maternal death during pregnancy is associated with PE and eclampsia, which could affect the liver, kidneys, brain, and the clotting system.

World Health Organization (WHO) in 1995 defined low birth weight (LBW) as any live birth of <2500 g and very low birth weight to be <1500 g. WHO defines preterm birth as any live birth at <37 weeks of gestation period [11, 12]. More than 33% of the infant mortality is attributed to the preterm low birth weight (PTLW), and surviving infants also have increased morbidity to congenital, neurological disabilities, and various developmental defects.

Little reduction in incidence of adverse pregnancy outcomes has occurred despite advances in technology, promotion of prenatal care, and continued scientific efforts. Investigations to detect the potential causative factors for adverse pregnancy outcome include infection and/or inflammation in the reproductive tract and at sites remote from the feto-placental unit. The relationship between adverse pregnancy outcomes and maternal periodontal infections has been studied extensively over the past 10 years, as periodontal infection is most prevalent in populations with highest risk of adverse pregnancy outcomes.
