A case-control study to investigate an association between adverse pregnancy outcome and periodontal disease

Pregnancy and Dentistry: A Literature Review on Risk Management during Dental Surgical Procedures

Background: Pregnancy is a unique moment in a woman’s life, accompanied with several physiologic changes that have an impact on oral health. Aim of the study: The purpose of the present study was to conduct a critical review of published literature regarding pregnancy and dentistry, the most frequent oral diseases that are encountered during pregnancy, their correlation to adverse pregnancy events, and safe dental treatments that can be performed during pregnancy. Methods: A Medline/COCHRANE search was carried using specific keywords and MeSH terms, combined with the boolean operators “OR” and “AND”. Results: The search led to 146 publications including guidelines, meta-analyses, systematic and non-systematic reviews, published between 2000 and 2021. Discussion and conclusions: Due to the increased inflammatory and immune body response that characterizes pregnancy, periodontal conditions are often aggravated during pregnancy and periodontal disease encountered frequently in pregnant patients. There are conflicting study results in the literature regarding the association between periodontitis and adverse pregnancy outcomes. Periodontal treatment did not show a significant reduction in the adverse outcomes. Many dentists, often due to lack of information, are reluctant to provide dental treatment to pregnant women. However, preventive and restorative dental treatment is safe during pregnancy. Diagnostic radiographs may be performed after the first trimester if absolutely necessary. Analgesics (such as paracetamol) and anesthetics (such as lidocaine) are also considered safe. In case of infection, antibacterial drugs such as amoxicillin, ampicillin, and some cephalosporines and macrolides can also be prescribed. Organogenesis takes place in the first trimester, the time during which the fetus is susceptible to severe malformations (teratogenesis). The ideal time to perform dental treatment is the second trimester (week 17 to 28). However, acute pain or infections make the intervention of the dentist absolutely necessary and emergency treatment can be performed during the whole pregnancy period.

Association between periodontal indexes and biomarkers in gingival crevicular fluid and preterm birth in pregnancy: a nested case-control study

OBJECTIVES

This study aimed to investigate the association between periodontal indexes and biomarkers in gingival crevicular fluid (GCF) and preterm birth (PTB) in pregnancy, as well as to assess the clinical value of these indexes as predictors of PTB.

METHODS

A nested case-control study was conducted. A total of 300 systematically healthy pregnant women were selected within 36 weeks of gestation and grouped according to the enrolled weeks. Periodontal indexes, including probing depth (PD), bleeding index (BI), gingival index (GI), and five biomarkers in GCF, including interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), and 8-hydroxy-2-deoxyguanosine (8-OHdG) were measured at the enrolled date. The detailed birth outcome was recorded.

RESULTS

Only women at 24-28 weeks of gestation per PTB case (four full-term births) were selected as controls subjects, PTB displayed significantly greater GI, BI, and 8-OHdG (P<0.05). Logistic regression analysis revealed that BI and 8-OHdG were the dependent risk factors of PTB (OR=5.90, P=0.034; OR=1.18, P=0.045, respectively). The areas under the receiver operating characteristic curve (ROC) of BI and 8-OHdG were 0.80 and 0.69, and that of the combined detection was 0.82, which was larger than the individual detection, although the differences were not significant (P>0.05).

CONCLUSIONS

Increased BI and 8-OHdG at 24-28 weeks of gestation are risk factors for PTB. Their combined detection may have some value in the prediction of PTB, but further studies with a larger sample size are needed to explore it and thus provide experiment evidence for establishing an early warning system for PTB in pregnant women with periodontal disease.

Influence of female sex hormones in different stages of women on periodontium

The primary etiologic factor for periodontal diseases is “Dental plaque.” Although pathogenic bacteria in dental plaque are required for the incidence of periodontal disease, a susceptible host is also very important. The susceptibility of the host can be modified by many systemic factors with hormones level being one. The periodontium shows an exaggerated inflammatory response to plaque modified by female sex hormones during puberty, pregnancy, in women taking oral contraceptives, and at the postmenopausal stage. This review provides an in detail analysis of how periodontium is influenced by the fluctuation in sex steroid hormones of females during different phases of their lifetime and to discuss how much the same hormone at different ages and stages shows an exaggerated gingival response to plaque.

Effects of periodontal disease on systemic health

About one in two adults in the United States has periodontal disease. Chronic periodontitis is an oral disease affecting the supporting structures of the teeth leading to progressive loss of the attachment apparatus and bone around teeth. It is characterized by gingival pocket formation and/or gingival recession. The disease is initiated by bacteria and their components like lipopolysaccharide and causes a heightened host inflammatory response. This cascade of inflammatory response ultimately leads to an increased osteoclastic activity and bone loss. Individuals with periodontitis have increased systemic levels of acute phase proteins, plasma antibody levels, coagulation factor, total white blood cell count, neutrophils, C reactive protein (CRP), and cytokines such as INF- gamma (Interferon gamma), TNF-α (Tumor necrosis Factor- Alpha), IL (Interleukin)-1β, IL-2 and IL-6. As periodontitis works on the same chronic inflammation model seen in systemic diseases, there is sufficient evidence to suggest a bi-directional link between the two. This article summarizes the established associations between periodontal disease and systemic health.

Treating periodontal disease for preventing adverse birth outcomes in pregnant women

BACKGROUND

Periodontal disease has been linked with a number of conditions, such as cardiovascular disease, stroke, diabetes and adverse pregnancy outcomes, all likely through systemic inflammatory pathways. It is common in women of reproductive age and gum conditions tend to worsen during pregnancy. Some evidence from observational studies suggests that periodontal intervention may reduce adverse pregnancy outcomes. There is need for a comprehensive Cochrane review of randomised trials to assess the effect of periodontal treatment on perinatal and maternal health.

OBJECTIVES

To assess the effects of treating periodontal disease in pregnant women in order to prevent or reduce perinatal and maternal morbidity and mortality.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 6 October 2016), Cochrane Pregnancy and Childbirth's Trials Register (to 7 October 2016), the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 9) in the Cochrane Library, MEDLINE Ovid (1946 to 6 October 2016), Embase Ovid (1980 to 6 October 2016), and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 6 October 2016). ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials on 6 October 2016. We placed no restrictions on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) investigating the effects of periodontal treatment in preventing or reducing perinatal and maternal morbidity and mortality. We excluded studies where obstetric outcomes were not reported.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts and extracted data using a prepiloted data extraction form. Missing data were obtained by contacting authors and risk of bias was assessed using Cochrane's 'Risk of bias' tool. Where appropriate, results of comparable trials were pooled and expressed as risk ratios (RR) or mean differences (MD) with 95% confidence intervals (CI) . The random-effects model was used for pooling except where there was an insufficient number of studies. We assessed the quality of the evidence using GRADE.

MAIN RESULTS

There were 15 RCTs (n = 7161 participants) meeting our inclusion criteria. All the included studies were at high risk of bias mostly due to lack of blinding and imbalance in baseline characteristics of participants. The studies recruited pregnant women from prenatal care facilities who had periodontitis (14 studies) or gingivitis (1 study).The two main comparisons were: periodontal treatment versus no treatment during pregnancy and periodontal treatment versus alternative periodontal treatment. The head-to-head comparison between periodontal treatments assessed a more intensive treatment versus a less intensive one.Eleven studies compared periodontal treatment with no treatment during pregnancy. The meta-analysis shows no clear difference in preterm birth < 37 weeks (RR 0.87, 95% CI 0.70 to 1.10; 5671 participants; 11 studies; low-quality evidence) between periodontal treatment and no treatment. There is low-quality evidence that periodontal treatment may reduce low birth weight < 2500 g (9.70% with periodontal treatment versus 12.60% without treatment; RR 0.67, 95% CI 0.48 to 0.95; 3470 participants; 7 studies).It is unclear whether periodontal treatment leads to a difference in preterm birth < 35 weeks (RR 1.19, 95% CI 0.81 to 1.76; 2557 participants; 2 studies; ) and < 32 weeks (RR 1.35, 95% CI 0.78 to 2.32; 2755 participants; 3 studies), low birth weight < 1500 g (RR 0.80, 95% CI 0.38 to 1.70; 2550 participants; 2 studies), perinatal mortality (including fetal and neonatal deaths up to the first 28 days after birth) (RR 0.85, 95% CI 0.51 to 1.43; 5320 participants; 7 studies; very low-quality evidence), and pre-eclampsia (RR 1.10, 95% CI 0.74 to 1.62; 2946 participants; 3 studies; very low-quality evidence). There is no evidence of a difference in small for gestational age (RR 0.97, 95% CI 0.81 to 1.16; 3610 participants; 3 studies; low-quality evidence) when periodontal treatment is compared with no treatment.Four studies compared periodontal treatment with alternative periodontal treatment. Data pooling was not possible due to clinical heterogeneity. The outcomes reported were preterm birth < 37 weeks, preterm birth < 35 weeks, birth weight < 2500 g, birth weight < 1500 g and perinatal mortality (very low-quality evidence). It is unclear whether there is a difference in < 37 weeks, preterm birth < 35 weeks, birth weight < 2500 g, birth weight < 1500 g and perinatal mortality when different periodontal treatments are compared because the quality of evidence is very low.Maternal mortality and adverse effects of the intervention did not occur in any of the studies that reported on either of the outcomes.

AUTHORS' CONCLUSIONS

It is not clear if periodontal treatment during pregnancy has an impact on preterm birth (low-quality evidence). There is low-quality evidence that periodontal treatment may reduce low birth weight (< 2500 g), however, our confidence in the effect estimate is limited. There is insufficient evidence to determine which periodontal treatment is better in preventing adverse obstetric outcomes. Future research should aim to report periodontal outcomes alongside obstetric outcomes.

Further evidence for periodontal disease as a risk indicator for adverse pregnancy outcomes

BACKGROUND

Although there is increasing evidence to suggest an association between periodontal disease and adverse pregnancy outcomes, the issue remains controversial.

STUDY OBJECTIVE

This study tested the hypothesis that periodontal disease is a risk indicator for preterm delivery of low-birthweight infants.

MATERIALS AND METHODS

The study sample comprised 443 pregnant women with a mean (± standard deviation) age of 24.13 (±5.30) years. At first visit, maternal oral health status was assessed by the measurement of probing pocket depth and clinical attachment loss, and periodontal status was graded as absent, mild, moderate or severe. An association was sought between pregnancy outcomes and maternal periodontal status.

RESULTS

While controlling for other factors, significant associations were found between pregnancy outcomes and maternal periodontal index scores.

CONCLUSION

This study provides further evidence that periodontal disease is a risk indicator for adverse pregnancy outcomes.

Periodontitis, cardiovascular disease and pregnancy outcome--focal infection revisited?

Over the last two decades there has been a renewed interest around the possible effects of periodontal disease on both cardiovascular health and pregnancy outcome (among other diseases), a topic which has interested science for hundreds of years. These have led to a range of studies, workshops and consensus documents being published, with corresponding coverage in general and professional media. In this article the authors summarise the history and supporting theories behind such associations, whether clinical studies have been able to confirm these and what this might mean for general practitioners who are questioned on this topic by patients.

The effects of periodontal treatment on pregnancy outcomes

BACKGROUND

Preterm infants are at greater risk than term infants for physical and developmental disorders. Morbidity and mortality increases as gestational age at delivery decreases. Observational studies indicate an association between poor periodontal health and risk for preterm birth or low birthweight, making periodontitis a potentially modifiable risk factor for prematurity.

AIM

To identify randomized controlled trials (RCTs) published between January 2011 and July 2012 and discuss all published RCTs testing whether periodontal therapy reduces rates of preterm birth and low birthweight.

METHODS

Search of databases including PubMed, ISI Web of Science and Cochrane Library.

RESULTS

The single RCT identified showed no significant effect of periodontal treatment on birth outcomes.

DISCUSSION

All published trials included non-surgical periodontal therapy; only two included systemic antimicrobials as part of test therapy. The trials varied substantially in terms of sample size, obstetric histories of subjects, study preterm birth rates and the periodontal treatment response. The largest trials--also judged to be high-quality and at low risk of bias--have yielded consistent results, and indicate that treatment does not alter rates of adverse pregnancy outcomes.

CONCLUSION

Non-surgical periodontal therapy, scaling and root planing, does not improve birth outcomes in pregnant women with periodontitis.

The effects of periodontal treatment on pregnancy outcomes

BACKGROUND

Preterm infants are at greater risk than term infants for physical and developmental disorders. Morbidity and mortality increases as gestational age at delivery decreases. Observational studies indicate an association between poor periodontal health and risk for preterm birth or low birthweight, making periodontitis a potentially modifiable risk factor for prematurity.

AIM

To identify randomized controlled trials (RCTs) published between January 2011 and July 2012 and discuss all published RCTs testing whether periodontal therapy reduces rates of preterm birth and low birthweight.

METHODS

Search of databases including PubMed, ISI Web of Science and Cochrane Library.

RESULTS

The single RCT identified showed no significant effect of periodontal treatment on birth outcomes.

DISCUSSION

All published trials included non-surgical periodontal therapy; only two included systemic antimicrobials as part of test therapy. The trials varied substantially in terms of sample size, obstetric histories of subjects, study preterm birth rates and the periodontal treatment response. The largest trials - also judged to be high-quality and at low risk of bias - have yielded consistent results, and indicate that treatment does not alter rates of adverse pregnancy outcomes.

CONCLUSION

Non-surgical periodontal therapy, scaling and root planing, does not improve birth outcomes in pregnant women with periodontitis.

Epidemiology of association between maternal periodontal disease and adverse pregnancy outcomes--systematic review

BACKGROUND AND OBJECTIVES

There is still debate regarding potential relationships between maternal periodontitis during pregnancy and adverse pregnancy outcomes. The aim of this systematic review was to synthesize the available epidemiological evidence on this association.

DATA SOURCES

Combined electronic and hand search of MEDLINE, EMBASE, WEB OF SCIENCE and Cochrane Central Register databases.

STUDY ELIGIBILITY CRITERIA

Original publications reporting data from cross-sectional, case-control or prospective cohort epidemiological studies on the association between periodontal status and preterm birth, low birthweight (LBW) or preeclampsia. The search was not limited to publications in English. All selected studies provided data based on professional assessments of periodontal status, and outcome variables, including preterm birth (<37 weeks gestation), LBW (<2500 g), gestational age, small for gestational age, birthweight, pregnancy loss or miscarriage, or pre-eclampsia.

PARTICIPANTS

Pregnant women with or without periodontal disease, and with or without adverse pregnancy outcomes, assessed either during pregnancy or postpartum. No intervention studies were included. Study appraisal and synthesis methods - Publications were assessed based on predefined screening criteria including type of periodontal assessment, consistency in the timing of the periodontal assessment with respect to gestational age, examiner masking and consideration of additional exposures and confounders.

RESULTS

Maternal periodontitis is modestly but significantly associated with LBW and preterm birth, but the use of a categorical or a continuous exposure definition of periodontitis appears to impact the findings: Although significant associations emerge from case-control and cross-sectional studies using periodontitis "case definitions," these were substantially attenuated in studies assessing periodontitis as a continuous variable. Data from prospective studies followed a similar pattern, but associations were generally weaker. Maternal periodontitis was significantly associated with pre-eclampsia.

LIMITATIONS

There is a high degree of variability in study populations, recruitment and assessment, as well as differences in how data are recorded and handled. As a result, studies included in meta-analyses show a high degree of heterogeneity.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Maternal periodontitis is modestly but independently associated with adverse pregnancy outcomes, but the findings are impacted by periodontitis case definitions. It is suggested that future studies employ both continuous and categorical assessments of periodontal status. Further use of the composite outcome preterm LBW is not encouraged.

Is there a relationship between maternal periodontitis and pre-term birth? A prospective hospital-based case-control study

OBJECTIVE

The aim of this study is to verify the existence of an association between maternal periodontal disease and pre-term delivery in an unselected population of post-partum Turkish women.

MATERIALS AND METHODS

This case-control study was conducted on 100 women who gave birth in either a special or a government maternity hospital. The case group consisted of 50 mothers who had delivered an infant before 37 weeks' gestation and weighed under 2500 g. The control group included 50 mothers who had given birth to an infant with a birth weight of more than 2500 g and a gestational age of ≥37 weeks. Data of mothers and infants were collected using medical registers and questionnaires. Clinical periodontal examinations were carried out in six sites on every tooth in the mother's mouth. A participant who presented at least four teeth with one or more sites with a PPD ≥4 mm and CAL ≥3 mm at the same site was considered to have periodontal disease. Statistical methods included parametric and non-parametric tests and multiple logistic regression analysis.

RESULTS

There were no statistically significant differences between the cases and controls with regard to periodontal disease and pre-term delivery (OR = 1.48; 95% CI = 0.54-4.06).

CONCLUSION

The findings indicated that maternal periodontitis was not a possible risk factor for pre-term delivery. Further studies with additional clinical trials are needed to explore the possible relationship between periodontal disease and pre-term birth.

The effect of phase-I periodontal therapy on pregnancy outcome in chronic periodontitis patients

Recent studies have shown periodontal diseases (gum diseases) as risk factors for adverse pregnancy outcomes, such as prematurity and low birth weight. Objectives of the present study were to determine the effect of non-surgical periodontal therapy on pregnancy outcomes in women with periodontitis and to detect IgM and IgG status in cord blood during delivery. A total of 20 pregnant women in their 2nd trimester and associated with chronic generalised periodontitis were selected and recruited for the study. They were grouped into two: Group 1 (treatment group) and Group 2 (control). Periodontal parameters of all the subjects were recorded at baseline and after delivery. Data related to weight of the infant and type of delivery was recorded. During the delivery, cord blood was collected for the estimation of IgM and IgG antibodies. All the recordings were subjected for statistical analysis. The study concluded that maternal periodontitis was associated with adverse pregnancy outcomes.

Role of cytokines in development of pre-eclampsia associated with periodontal disease - Cohort Study

AIM

The present study was designed to find any association of cytokines in women with periodontal disease and development of pre-eclampsia in North Indian population.

MATERIALS AND METHODS

A total of 504 consecutively registered primigravida with a single live pregnancy were recruited at 14-18 weeks of gestation from antenatal clinic of Maulana Azad Medical College & associated Lok Nayak Hospital and Maulana Azad Institute of Dental Sciences, New Delhi. One periodontist performed oral health examination of all patients at inclusion into study. Blood samples were collected to measure the level of cytokines IL-4, IL-10, TNF-α and IFN-γ.

RESULTS

The profile of blood levels of cytokines from women with periodontal disease was observed. The log serum levels of TNF-α & IL-4 at 16-18 weeks of gestation were significantly higher in women with periodontal disease (4.13 ± 2.06; 0.47 ± 1.56 pg/ml respectively) than in women with healthy gums (2.16 ± 1.51; 0.02 ± 1.84 pg/ml respectively, p < 0.001). Periodontal disease is associated with log serum TNF-α levels at cut-off ≥14.43 pg/ml at sensitivity 71.2% and specificity 62% (OR = 4.04; 95%CI = 2.77-5.87). Woman with periodontal disease who later developed pre-eclampsia had lower levels of TNF-α (3.72 ± 1.33 pg/ml) than those with periodontal disease who did not develop pre-eclampsia (4.20 ± 2.15 pg/ml, p ≥ 0.05).

CONCLUSION

Reduced TNF-α level secretion in the early second trimester in women with periodontal disease appears to be associated with the development of pre-eclampsia.

Bi-directional relationship between pregnancy and periodontal disease

During pregnancy profound perturbations in innate and adaptive immunity impact the clinical course of a number of infectious diseases, including those affecting periodontal tissues. Conversely, it has been suggested that periodontal infections may increase the risk of adverse pregnancy outcomes. In this review, a summary of the literature associated with the bidirectional relationship between pregnancy and periodontal disease as well as the possible mechanisms behind this interaction were examined.

Evaluation of periodontal pathogens in amniotic fluid and the role of periodontal disease in pre-term birth and low birth weight

BACKGROUND

Pre-term birth and/or low birth weight (PTLBW) is a serious problem in developing countries. The absence of known risk factors in ≈ 50% of PTLBW cases has resulted in a continued search for other causes. The aim of this study was to examine the effect of periodontitis on pregnancy outcomes.

METHODS

Samples were taken from 50 pregnant women who underwent amniocentesis. Polymerase chain reaction was performed on amniotic fluid samples obtained during amniocentesis and on subgingival plaque samples to determine the presence of Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus and Eikenella corrodens. Plaque index, gingival index, bleeding on probing, probing depth and clinical attachment level were evaluated. Medical records were obtained after birth.

RESULTS

Social and demographic variables were similar among the Gingivitis (G), Localized Periodontitis (LP) and Generalized Periodontitis (GP) groups. Four subjects gave birth to PTLBW neonates. Campylobacter rectus, T. forsythia, P. gingivalis and F. nucleatum were detected in the amniotic fluid and subgingival plaque samples of three patients who gave birth to PTLBW neonates. The amniotic fluid sample from the fourth patient was not positive for any of the tested pathogens.

CONCLUSION

These findings suggest that the transmission of some periodontal pathogens from the oral cavity of the mother may cause adverse pregnancy outcomes. The results contribute to an understanding of the association between periodontal disease and PTLBW, but further studies are required to better clarify the possible relationship.

Perinatal periodontal disease reduces social behavior in male offspring

OBJECTIVE

Our objective was to verify whether prenatal maternal periodontitis is a risk factor for the development of central nervous system disorders in rats.

METHODS

Periodontitis was induced by placing a ligature around the upper and lower first molars in 9 female Wistar rats (experimental group); 9 rats were left unligated (control group). The maternal general activity in an open field was observed on gestational day (GD) 0, GD 4, and GD 14, and the maternal performance was assessed on the second day after birth. The pups' play behavior was assessed on postnatal day 30. The relative level of reelin was measured in the frontal cortex by real-time PCR analysis.

RESULTS

The results showed that, compared with the control group, (1) the general activity in female rats with periodontitis was decreased, (2) the maternal performance of these rats was not modified by periodontitis, (3) the play behavior of pups from dams with periodontitis was decreased, and (4) there were no differences in the frontal cortex reelin levels of pups from dams with periodontitis.

CONCLUSIONS

We conclude that pre- and postnatal periodontitis induces maternal sickness behavior and reduces the pups' play behavior without interference with frontal cortex reelin expression.

Association of maternal periodontal health with adverse pregnancy outcome

AIM

The present study aims to determine the association of periodontal disease (identified early in pregnancy) and adverse pregnancy outcomes in a North Indian population.

MATERIAL AND METHODS

  A total of 340 primigravida women, aged 20-35 years with single live pregnancy were recruited at 14-20 weeks period of gestation from the antenatal clinic. These women had undergone periodontal examination at time of recruitment. The pregnancy outcomes were recorded.

RESULTS

Out of 340 primigravida women, 147 (43.23%) women had gingivitis and 61 (17.94%) women had periodontitis. Periodontitis was found to be significantly associated with pre-eclampsia, intrauterine growth restriction, preterm delivery, and low birthweight with odds ratios (95% confidence interval) of 7.48 (2.72-22.42), 3.35 (1.20-9.55), 2.72 (1.30-5.68) and 3.03 (1.53-5.97), respectively.

CONCLUSIONS

The study shows a significant association between periodontitis (but not with gingivitis) and adverse pregnancy outcomes. Maternal periodontitis is associated with an increased risk of pre-eclampsia, intrauterine growth restriction, preterm delivery and low birthweight infants.

Pathogenic mechanisms linking periodontal diseases with adverse pregnancy outcomes

In the last 2 decades, a large proportion of studies have focused on the relationship between maternal periodontal disease and poor obstetric outcomes. The aim of the present review is to summarize the current knowledge about human studies on the pathogenetic mechanisms linking periodontal diseases with adverse pregnancy outcomes. A search of the medical literature was conducted using NIH (National Institute of Health) Pubmed through April 2011. Articles were identified with the Medical Subject Heading (MeSH) and free text terms "small for gestational age (SGA)," "preeclampsia," "preterm labor," and "periodontal disease." Experimental human studies have shown that periodontal pathogens may disseminate toward placental and fetal tissues accompanied by an increase in inflammatory mediators in the placenta. As such, new inflammatory reactions within the placental tissues of the pregnant woman may occur, the physiological levels of prostaglandin E(2) (PGE(2)) and tumor necrosis factor-α (TNF-α) in the amniotic fluid may increase and eventually lead to premature delivery. Although many data from clinical trials suggest that periodontal disease may increase the adverse pregnancy outcome, the exact pathogenetic mechanism involved remains controversial. The findings explain the potential link between periodontal infections and adverse pregnancy outcomes. First, periodontal bacteria can directly cause infections both of the uteroplacenta and the fetus; second, systemic inflammatory changes induced by periodontal diseases can activate responses at the maternal-fetal interface. Of note, associative studies have produced different results in different population groups and no conclusive evidence has still been produced for the potential role of preventive periodontal care to reduce the risk factors of preterm birth.

Maternal periodontitis as a risk factor for prematurity

BACKGROUND

The aim of this study was to investigate maternal periodontitis associated with prematurity.

METHODS

We carried out a case-control study including 718 puerperae who experienced a spontaneous delivery: 360 cases (premature) and 358 controls (full-term). Sociodemographic, obstetric, prenatal, perinatal and periodontal data were obtained within 48 h after delivery. Periodontitis was defined as probing depth ≥ 4 mm and attachment loss ≥ 3 mm at same site, for ≥ 4 teeth.

RESULTS

Periodontitis was associated with prematurity (odds ratio 6.95; confidence interval 3.69-13.09). Prematurity was associated with maternal age < 20 years, family income < one minimum salary, maternal schooling < 8 years, premature birth history, premature membrane rupture, ruptured membranes > 24 h, smoking, urinary tract infection, leukorrhea, pre-eclampsia, prenatal consultations < 3 and precarious housing. After multivariate confounder adjustments, periodontitis remained independently associated with prematurity (odds ratio 6.05; confidence interval 3.01-12.16).

CONCLUSIONS

Periodontitis is strongly associated with prematurity, indicating necessity for regular periodontal investigation and treatment during pregnancy.

Periodontitis-associated risk factors in pregnant women

OBJECTIVE

The main objective of this study was to investigate the risk factors associated with periodontitis in pregnant women.

METHODS

This study was conducted in two stages. In Stage 1, a cross-sectional study was conducted to determine the prevalence of periodontitis among 810 women treated at the maternity ward of a university hospital. In Stage 2, the factors associated with periodontitis were investigated in two groups of pregnant women: 90 with periodontitis and 720 without. A hierarchized approach to the evaluation of the risk factors was used in the analysis, and the independent variables related to periodontitis were grouped into two levels: 1) socio-demographic variables; 2a) variables related to nutritional status, smoking, and number of pregnancies; and 2b) variables related to oral hygiene. Periodontitis was defined as a probing depth ≥ 4 mm and an attachment loss ≥ 3 mm at the same site in four or more teeth. A logistic regression analysis was also performed.

RESULTS

The prevalence of periodontitis in this sample was 11%. The variables that remained in the final multivariate model with the hierarchized approach were schooling, family income, smoking, body mass index, and bacterial plaque.

CONCLUSION

The factors identified underscore the social nature of the disease, as periodontitis was associated with socioeconomic, demographic status, and poor oral hygiene.

Periodontal treatment during pregnancy decreases the rate of adverse pregnancy outcome: a controlled clinical trial

Objectives

The aim of this study was to evaluate the effects of non-surgical treatment of periodontal disease during the second trimester of gestation on adverse pregnancy outcomes.

Material and Methods

Pregnant patients during the 1^st and 2^nd trimesters at antenatal care in a Public Health Center were divided into 2 groups: NIG – "no intervention" (n=17) or IG- "intervention" (n=16). IG patients were submitted to a non-surgical periodontal treatment performed by a single periodontist consisting of scaling and root planning (SRP), professional prophylaxis (PROPH) and oral hygiene instruction (OHI). NIG received PROPH and OHI during pregnancy and were referred for treatment after delivery. Periodontal evaluation was performed by a single trained examiner, blinded to periodontal treatment, according to probing depth (PD), clinical attachment level (CAL), plaque index (PI) and sulcular bleeding index (SBI) at baseline and 35 gestational weeks-28 days post-partum. Primary adverse pregnancy outcomes were preterm birth (<37 weeks), low birth weight (<2.5 kg), late abortion (14-24 weeks) or abortion (<14 weeks). The results obtained were statistically evaluated according to OR, unpaired t test and paired t test at 5% significance level.

Results

No significant differences were observed between groups at baseline examination. Periodontal treatment resulted in stabilization of CAL and PI (p>0.05) at IG and worsening of all periodontal parameters at NIG (p<0.0001), except for PI. Significant differences in periodontal conditions of IG and NIG were observed at 2nd examination (p<0.001). The rate of adverse pregnancy outcomes was 47.05% in NIG and 6.25% in IG. Periodontal treatment during pregnancy was associated to a decreased risk of developing adverse pregnancy outcomes [OR=13.50; CI: 1.47-123.45; p=0.02].

Conclusions

Periodontal treatment during the second trimester of gestation contributes to decrease adverse pregnancy outcomes.

Periodontal disease and pregnancy outcomes: time to move on?

Maternal periodontal disease is a highly prevalent condition that has been studied extensively in relation to adverse pregnancy outcomes, including preterm delivery, preeclampsia, and low birth weight. Investigators speculate that hematogenous transport of bacteria and/or pro-inflammatory mediators from sites of periodontal infection into the placenta, fetal membranes, and amniotic cavity induces pathological processes that lead to these adverse outcomes. Preliminary observational studies supported this hypothesis, but more recent work by our group and others do not demonstrate an increased risk of adverse pregnancy outcomes among women with periodontal disease, and most randomized trials fail to demonstrate improved perinatal outcomes following treatment of periodontal disease in pregnancy.

Maternal periodontitis and the causes of preterm birth: the case-control Epipap study

AIM

To analyse the association between maternal periodontitis and preterm birth (<37 weeks' gestation) according to the causes of preterm birth.

MATERIALS AND METHODS

Epipap is a case-control multi-centre study of singleton livebirths. One thousand one hundred and eight women with preterm deliveries and 1094 with deliveries at term (> or =37 weeks) at six French maternity units were included. Periodontal examinations after delivery identified localized and generalized periodontitis. Cases were classified according to four causes of preterm birth. Polytomous logistic regression analysis was used to control for confounders (maternal age, parity, nationality, educational level, marital status, employment during pregnancy, body mass index before pregnancy, smoking status) and the examiner.

RESULTS

Localized periodontitis was identified in 129 (11.6%) cases and in 118 (10.8%) control women and generalized periodontitis in 148 (13.4%) and 118 (10.8%), respectively. A significant association was observed between generalized periodontitis and induced preterm birth for pre-eclampsia [adjusted odds ratio 2.46 [95% confidence intervals (95% CI)1.58-3.83]. Periodontitis was not associated with spontaneous preterm birth or preterm premature rupture of membranes or with the other causes.

CONCLUSION

Maternal periodontitis is associated with an increased risk of induced preterm birth due to pre-eclampsia.

Women's attitudes to and perceptions of oral health and dental care during pregnancy

AIMS

To assess pregnant women's opinions on and perceptions of oral health and their relationship to oral hygiene and dental care practices.

METHODS

Questionnaire survey on perceived oral health, oral hygiene and utilization of dental services among 649 nulliparae attending for antenatal care at all public antenatal clinics in Adelaide, South Australia.

RESULTS

Women rated their general health significantly better than their oral health (P<0.001) and attributed more importance to healthy teeth for their baby than for themselves (P<0.001). Only 35% had dental care during pregnancy; 35% had no dental visit for at least two years and 27% reported cost as a major deterrent. Eighteen percent had experienced gingival bleeding before pregnancy and 41% during pregnancy. Gingival bleeding outside pregnancy was clearly related to perceived oral health (P<0.001), but this was less so for bleeding during pregnancy. The latter was not related to age, level of education, employment, marital status, or smoking habits. Only 38% of women with gingival bleeding in pregnancy had a dental care visit in pregnancy and 28% considered their oral health as very good.

CONCLUSIONS

Many pregnant women do not perceive gingival bleeding as indicating inflammatory disease and seek no professional help for it. Maternity care providers need to devote more attention to oral health in antenatal clinics and antenatal education.

Periodontal therapy for pregnant women and cases of low birthweight: an intervention study

BACKGROUND

Over the past decade, strong evidence for an association between maternal periodontitis and low birthweight has started to appear. However, few intervention studies have been proposed for investigating this hypothesis. The aim of this study was to evaluate whether periodontal therapy among pregnant women would reduce the incidence of low birthweight.

METHODS

A nonrandomized intervention study was performed, with two control groups. The sample comprised 339 pregnant women: 141 in the experimental group (treated for periodontitis), 145 in control group 1 (without periodontitis) and 53 in control group 2 (with untreated periodontitis). The experimental group received periodontal treatment throughout pregnancy, whereas control group 1 was only monitored over the same period. After delivery, birthweight information on the newborns was obtained. The analysis procedures consisted of stratified analysis followed by logistic regression.

RESULTS

The frequency of low birthweight among the women with treated periodontitis was 9.22%, while it was 13.10% in the group without periodontal disease. However, the difference was not statistically significant (RR 0.72; 95% CI 0.36-1.45). The occurrence of this outcome in the group with untreated periodontitis (24.53%) was greater than in the other two groups.

CONCLUSION

This suggests that periodontal therapy is a protective factor for birthweight.

Periodontal disease and adverse pregnancy outcomes

Periodontal disease is a common infectious disease in women of reproductive age. The disease is often not diagnosed and in studies of over 10 000 women has been associated with preterm birth, small for gestational age newborns, and preeclampsia. It has been shown in a smaller number of women that treatment of periodontal disease may reduce the rate of preterm birth. The pregnancy complications of periodontal disease may be due to lipopolysaccharide from the periodontal pockets inciting prostaglandin pathways controlling parturition. Three large randomized controlled trials of treatment of periodontal disease are underway and may provide confirmation of the importance of periodontal disease in causing complications of pregnancy.

Periodontal disease and adverse pregnancy outcomes: is there an association?

OBJECTIVE

We assessed the risk of adverse pregnancy outcomes (preterm birth [PTB], preeclampsia [PRE], fetal growth restriction [FGR], or perinatal death) in women with periodontal disease (PD) compared to those without.

STUDY DESIGN

A multicenter prospective cohort study enrolled women from 3 sites between 6 and 20 weeks' gestation. The presence of PD was defined as periodontal attachment loss > or = to 3 mm on 3 or more teeth. The primary binary composite outcome included PRE, PTB, FGR, or perinatal death. Multivariable logistic regression (MVLR) was used to control for confounders.

RESULTS

Three hundred eleven patients with and 475 without PD were included. There was no association between PD and the composite outcome, PRE, or PTB in unadjusted analyses. There was no association between PD and the composite outcome (adjusted odds ratio [AOR], 0.81; 95% confidence interval [CI], 0.58-1.15; P = .24), preeclampsia (AOR, 0.71; 95% CI, 0.37-1.36; P = .30), or preterm birth (AOR, 0.77; 95% CI, 0.49-1.21; P = .25) after adjusting for relevant confounders.

CONCLUSION

Despite the body of literature suggesting an association between PD and adverse pregnancy outcomes in urban populations, this large prospective study failed to demonstrate an association.

Is maternal periodontal disease a risk factor for preterm delivery?

Several studies have suggested an association between maternal periodontal disease and preterm delivery, but this has not been a consistent finding. In 2006-2007, the authors examined the relation between maternal periodontal disease and preterm delivery among 467 pregnant Thai women who delivered a preterm singleton infant (<37 weeks' gestation) and 467 controls who delivered a singleton infant at term (> or =37 weeks' gestation). Periodontal examinations were performed within 48 hours after delivery. Participants' periodontal health status was classified into 4 categories according to the extent and severity of periodontal disease. Logistic regression was used to estimate odds ratios and 95% confidence intervals. Preterm delivery cases and controls were similar with regard to mean probing depth, mean clinical attachment loss, and mean percentage of sites exhibiting bleeding on probing. After controlling for known confounders, the authors found that severe clinical periodontal disease was not associated with an increased risk of preterm delivery (odds ratio = 1.20, 95% confidence interval: 0.67, 2.16). In addition, there was no evidence of a linear increase in risk of preterm delivery or its subtypes associated with increasing severity of periodontal disease (P(trend) > 0.05). The results of this case-control study do not provide convincing evidence that periodontal disease is associated with preterm delivery or its subtypes among Thai women.

A critical assessment of adverse pregnancy outcome and periodontal disease

BACKGROUND

Pre-term birth is a major cause of infant mortality and morbidity that has considerable societal, medical, and economic costs. The rate of pre-term birth appears to be increasing world-wide and efforts to prevent or reduce its prevalence have been largely unsuccessful.

AIM

To review the literature for studies investigating periodontal disease as a possible risk factor for pre-term birth and adverse pregnancy outcomes.

MAIN FINDINGS AND CONCLUSION

Variability among studies in definitions of periodontal disease and adverse pregnancy outcomes as well as widespread inadequate control for confounding factors and possible effect modification make it difficult to base meaningful conclusions on published data. However, while there are indications of an association between periodontal disease and increased risk of adverse pregnancy outcome in some populations, there is no conclusive evidence that treating periodontal disease improves birth outcome. Based on a critical qualitative review, available evidence from clinical trials indicates that, although non-surgical mechanical periodontal treatment in the second trimester of pregnancy is safe and effective in reducing signs of maternal periodontal disease, it does not reduce the rate of pre-term birth. Clinical trials currently underway will further clarify the potential role of periodontal therapy in preventing adverse birth outcomes. Regardless of the outcomes of these trials, it is recommended that large, prospective cohort studies be conducted to assess risk for adverse pregnancy outcome in populations with periodontal disease. It is critical that periodontal exposure and adverse birth outcomes be clearly defined and the many potential confounding factors and possible effect modifiers for adverse pregnancy outcome be controlled in these studies. If periodontal disease is associated with higher risk of adverse pregnancy outcome in these specific populations, large multicenter randomized-controlled trials will be needed to determine if prevention or treatment of periodontal disease, perhaps combined with other interventions, has an effect on adverse pregnancy outcome in these women.

Periodontal disease definition may determine the association between periodontitis and pregnancy outcomes

AIM

The aim of this secondary analysis is to explore whether the application of different definition criteria of periodontitis, used in other similar studies, has an influence on the significance of the association between periodontitis and prematurity or low birth weight.

MATERIAL AND METHODS

Fourteen periodontitis definitions and more than 50 periodontal disease continuous measurements, found in 23 published studies, were applied to a cohort study that included 1296 pregnant women. The associations with adverse pregnancy outcomes were analysed using logistic regression analysis.

RESULTS

Six of the 14 tested definitions of periodontitis resulted in statistically significant adjusted odds ratios (ORs) for some of the adverse pregnancy outcomes, while no significance was found for the other eight case definitions. Out of more than 50 periodontal continuous measurements tested, only 17 demonstrated statistically significant ORs.

CONCLUSIONS

Our results support the hypothesis that the significance of the association between periodontal disease and pregnancy outcomes may be determined by the periodontal disease definition or measurement used.

Periodontal disease and pregnancy outcomes: state-of-the-science

To examine the existing evidence on the relationship between periodontal disease and adverse pregnancy outcomes, we conducted a systematic review of studies published up to December 2006. Studies published in full text were identified by searching computerized databases (e.g., MEDLINE, EMBASE). A meta-analysis was performed to pool the effect size of the clinical trials. Forty-four studies were identified (26 case-control studies, 13 cohort studies, and 5 controlled trials). The studies focused on preterm low birth weight, low birth weight, preterm birth, birth weight by gestational age, miscarriage or pregnancy loss, preeclampsia, and gestational diabetes mellitus. Of the chosen studies, 29 suggested an association between periodontal disease and increased risk of adverse pregnancy outcome (odds ratios [ORs] ranging from 1.10 to 20.0) and 15 found no evidence of an association (ORs ranging from 0.78 to 2.54). A meta-analysis of the clinical trials suggested that oral prophylaxis and periodontal treatment may reduce the rate of preterm low birth weight (pooled risk ratio (RR): 0.53, 95% confidence interval [CI]: 0.30-0.95, P < 0.05), but did not significantly reduce the rates of preterm birth (pooled RR: 0.79, 95% CI: 0.55-1.11, P > 0.05) or low birth weight (pooled RR: 0.86, 95% CI: 0.58%1.29, P > 0.05). The authors conclude that periodontal disease may be associated with increased risk of adverse pregnancy outcomes. More methodologically rigorous studies are needed in this field. Currently, there is insufficient evidence to support the provision of periodontal treatment during pregnancy for the purpose of reducing adverse pregnancy outcomes.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader should be able to state that the published literature is not vigorous to clinically link periodontal disease and/or its treatment to specific adverse pregnancy outcomes, and explain that more rigorous studies with world-wide agreed-upon definitions are particularly needed before periodontal disease treatment can be recommended.

Periodontal disease as a risk factor for adverse pregnancy outcomes: a prospective cohort study

AIM

The aim of this study was to determine the association between periodontitis and the incidence of preterm birth (PB), low birth weight (LBW) and preterm low birth weight (PLBW) MATERIAL AND METHODS: One thousand and ninety-six women were enrolled. Periodontal data, pregnancy outcome variables and information on other factors that may influence adverse pregnancy outcomes were collected. Data were analysed using a logistic regression model.

RESULTS

The incidence of PB and LBW was 6.6% and 6.0%, respectively. The incidence of PLBW was 3.3%. PB was related to mother's age, systemic diseases, onset of prenatal care, previous PBs, complications of pregnancy, type of delivery, the presence of untreated caries and the presence of periodontitis (odds ratio 1.77, 95% confidence interval: 1.08-2.88). LBW was related to mother's smoking habits, ethnicity, systemic diseases, previous LBW babies, complications of pregnancy and type of delivery. PLBW was related to mother's age, onset of prenatal care, systemic diseases, previous LBW babies, complications of pregnancy and type of delivery.

CONCLUSIONS

The factors involved in many cases of adverse pregnancy outcomes have still not being identified, although systemic infections may play a role. This study found a modest association between periodontitis and PB. Further research is required to establish whether periodontitis is a risk factor for PB and/or LBW.

Evaluation of the incidence of preterm low birth weight in patients undergoing periodontal therapy

BACKGROUND

Preterm low birth weight was reported to be related to periodontal infections that might influence the fetus-placenta complex. The aim of this study was to provide periodontal treatment for pregnant women and to evaluate if this treatment can interfere with pregnancy duration and weight of the newborn.

METHODS

The sample consisted of 450 pregnant women who were under prenatal care at a polyclinic in Três Corações, Brazil. Women with risk factors, such as systemic alterations (ischemic cardiopathy, hypertension, tuberculosis, diabetes, cancer, anemia, seizure, psychopathology, urinary tract infection, sexually transmitted diseases, asthma, and human immunodeficiency virus), and/or users of alcohol, tobacco, and drugs were excluded from the study. Data related to age, socioeconomic level, race, marital status, number of previous pregnancies, and previous preterm delivery also were evaluated. Initially, the sample was divided into two groups: 122 healthy patients (group 1) and 328 patients with periodontal disease (group 2). In group 2, 266 patients underwent treatment and 62 patients dropped out. After mothers gave birth, pregnancy duration and the weight of all infants were analyzed and recorded.

RESULTS

There was no statistical difference between the healthy and treated groups. However, there was a difference in the non-treated group, with a 79% incidence of preterm low birth weight. Educational level, previous preterm birth, and periodontal disease were related significantly to preterm delivery (P <0.001).

CONCLUSION

Periodontal disease was related significantly to preterm low birth weight.

Periodontal disease and pregnancy outcomes: exposure, risk and intervention

Despite the many advances in medicine, the rate of preterm birth has not significantly decreased in the United States over the past several decades. In fact, the rate rose in 2003 to more than 12% of all births in the United States. This equates to over half a million premature births in the United States alone. Consequently, the identification of risk factors for preterm birth which are amenable to intervention would have far-reaching and long-lasting effects. There is emerging evidence of a relationship between periodontal health and adverse pregnancy outcomes, particularly preterm birth/preterm low-birth-weight infants. Therefore this chapter explores the putative association between periodontal disease and infant prematurity, as well as the results of intervention studies which treated periodontal disease in order to reduce the incidence of prematurity. Of 31 published studies, 22 show a positive association between premature birth and periodontal disease. Ongoing studies are addressing the efficacy of periodontal treatment for decreasing the incidence of infant prematurity.

Exploring the relationship between periodontal disease and pregnancy complications

BACKGROUND

Increasing evidence suggests that maternal gingivitis and periodontitis may be a risk factor for preterm birth and other adverse pregnancy outcomes.

TYPES OF STUDIES REVIEWED

To clarify the possible mechanisms behind the association between periodontal disease and preterm delivery, the authors reviewed studies of the effect of infection with periodontal pathogens in animal models on pregnancy outcomes including fetal growth, placental structural abnormalities and neonatal health. After the first report, in 1996, of a potential association between maternal periodontal disease and delivery of a preterm/low-birth-weight infant in humans, many case control and prospective studies were published. This review summarizes these, as well as early studies involving periodontal intervention to reduce risk.

RESULTS

Although there are some conflicting findings and potential problems regarding uncontrolled underlying risk factors, most of the clinical studies indicate a positive correlation between periodontal disease and preterm birth. Recent studies also have shown that there are microbiologic and immunological findings that strongly support the association. The studies indicate that periodontal infection can lead to placental-fetal exposure and, when coupled with a fetal inflammatory response, can lead to preterm delivery. Data from animal studies raise the possibility that maternal periodontal infections also may have adverse long-term effects on the infant's development.

CLINICAL IMPLICATIONS

Education for patients and health care providers regarding the biological plausibility of the association and the potential risks is indicated, but there is insufficient evidence at this time for health care policy recommendations to provide maternal periodontal treatments for the purpose of reducing the risk of adverse pregnancy outcomes.

Chronic periodontitis and pre-term labour in Brazilian pregnant women: an association to be analysed

AIM

To investigate the association between chronic periodontitis (CP) and pre-maturity in a group of Brazilian pregnant women from the State of São Paulo.

MATERIALS AND METHODS

One hundred and twenty-four women were investigated consecutively in a cross-sectional study, between December 2003 and May 2005. Sixty-eight women had pre-term labour (PTL) and 56 had term labour. A periodontal examination was carried out to identify the presence of CP. Statistical analysis used the Fisher's exact test or chi(2) for the discrete variables and the Mann-Whitney test for the non-parametric variables. Odds ratio (OR) was calculated with a 95% confidence interval (CI), to evaluate the relation between CP and pre-maturity.

RESULTS

Periodontal indicators, such as clinical attachment loss (p<0.0001) and bleeding on probing (p=0.012), were observed more in the PTL group. The presence of CP increased the risk for PTL (OR: 4.7, 95% CI: 1.9-11.9), pre-term birth (PTB; OR: 4.9, 95% CI: 1.9-12.8) and low birth weight (<2500 g; OR: 4.2, 95% CI: 1.3-13.3). The pregnant women with PTL presented low levels of schooling (p=0.029) and the lowest number of pre-natal appointments (p=0.0001) when compared with those with term labour.

CONCLUSION

CP is strongly associated with PTL, PTB and low birth weight in a group of Brazilian pregnant women. These data point to the necessity of regularly investigating CP during pregnancy.

Pre-term delivery and periodontal disease: a case?control study from Croatia

AIM

The aim of this report was to assess the strength and influence of periodontitis as a possible risk factor for pre-term birth (PTB) in a cohort of 81 primiparous Croatian mothers aged 18-39 years.

METHODS

PTB cases (n = 17; mean age 25 +/- 2.9 years; age range 20-33 years) were defined as spontaneous delivery after less than 37 completed weeks of gestation that were followed by spontaneous labour or spontaneous rupture of membranes. Controls (full-time births) were normal births at or after 37 weeks of gestation (n = 64; mean age 25 +/- 2.9 years; age range 19-39 years). Information on known risk factors and obstetric factors included the current pregnancy history, maternal age at delivery, pre-natal care, nutritional status, tobacco use, alcohol use, genitourinary infections, vaginosis, gestational age, and birth weight. Full-mouth periodontal examination was performed on all mothers within 2 days of delivery.

RESULTS

PTB cases had significantly worse periodontal status than controls (p = 0.008). Multivariate logistic regression model, after controlling for other risk factors, demonstrated that periodontal disease is a significant independent risk factor for PTB, with an adjusted odds ratio of 8.13 for the PTB group (95% confidence interval 2.73-45.9).

CONCLUSION

Periodontal disease represents a strong, independent, and clinically significant risk factor for PTB in the studied cohort. There are strong indicators that periodontal therapy should form a part of preventive prenatal care in Croatia.