ABSTRACT
Aim:
Pregnancy-induced hormonal shifts can exacerbate periodontal disease, yet trimester-specific data, especially from sub-Saharan populations, are scarce. This study assessed and compared periodontal status and treatment needs between pregnant and non-pregnant women in the Democratic Republic of the Congo, with attention to changes across trimesters.
Materials and Methods:
A multicenter cross-sectional study included 307 pregnant women and 309 age-matched non-pregnant controls. Standardized clinical indices, including oral hygiene index-simplified, bleeding on probing, periodontal pocket depth (PPD), clinical attachment loss, and community periodontal index of treatment needs (CPITN) were used. Data were analyzed using Chi-square tests, t tests, and multivariate logistic regression.
Results:
Pregnant women exhibited significantly worse periodontal health. A higher proportion of pregnant women had PPD > 4 mm (26% vs. 19%, P = 0.049) and required advanced periodontal treatment (CPITN treatment need III: 26% vs. 18%, P = 0.013) compared to non-pregnant controls. Periodontal disease severity progressed with gestation: localized gingivitis peaked in the second trimester (50%), while periodontitis was most prevalent in the third trimester (59%). After adjusting for confounders, gestational status was independently associated with higher odds of periodontitis (OR = 2.87, 95% CI: 1.06–7.91).
Conclusion:
Pregnancy is significantly associated with deteriorating periodontal health and increased treatment needs, particularly in the second and third trimesters. These findings underscore the urgent need to integrate trimester-specific periodontal screening and preventive care into routine antenatal services to improve maternal oral and systemic health.
Keywords: CPITN, Democratic Republic of the Congo, gingivitis, maternal oral health, periodontal disease, periodontitis, pregnancy, trimester
INTRODUCTION
Pregnancy is associated with various changes that affect the oral cavity of women.[1] Oral-specific problems in the female population have long been the subject of research. Both physiological (puberty, menstruation, pregnancy, and menopause) and non-physiological factors (hormonal contraception and hormone therapy) influence oral health. During pregnancy, fluctuations in estrogen and progesterone levels lead to dilated and tortuous microvascularization in periodontal tissues, compromising host immunity, and increasing susceptibility to oral infections.[2]
Periodontitis is a chronic inflammatory condition caused by oral biofilm accumulation, leading to irreversible destruction of the supporting structures of the teeth.[3] Gingivitis, a milder and reversible form of periodontal disease, is one of the most prevalent oral conditions during pregnancy. Its onset is linked to elevated levels of sex steroid hormones, which also influence its severity.[4,5] This induced gingivitis appears during pregnancy from the 13th week of amenorrhea. Its overall prevalence varies from 30% to 100%.[6,7] Conversely, periodontitis affects 11% of pregnant women.[8,9]
Hormonal changes during pregnancy are a breeding ground for periodontal disease. This justifies paying more attention to oral health during this period.[10] The pathogenesis of periodontal disease in pregnant women is considered multifactorial, involving hormonal, genetic, and behavioral components.[11] The association between periodontitis and systemic diseases has been extensively documented.[12] These include cardiovascular diseases, pregnancy complications, metabolic disorders, and musculoskeletal conditions. Mechanistic links include elevated inflammatory markers (e.g., C-reactive protein [CRP]), prothrombotic factors, autoantibodies against cardiovascular tissues, dyslipidemia, and oxidative stress.[13,14,15] In addition, studies in patients with peri-implant mucositis have found that heavy smoking and infection with Porphyromonas gingivalis and Tannerella forsythia increase bleeding on probing (BOP).[16]
Studies comparing the prevalence of periodontal disease in pregnant and non-pregnant women are contradictory. Some authors reported a higher level of periodontitis and greater pocket depth in pregnant women than in non-pregnant women.[17] Other authors did not find a significant difference between the two groups.[18] However, studies evaluating trimester-specific variations in periodontal health and analyzing pregnant women’s treatment needs are lacking. The conflicting results from the previous studies, their small sample sizes, and the absence of trimester-specific data justify the present research. Our research question was to determine whether pregnant women with periodontal diseases had a similar periodontal status to non-pregnant women. The study aimed to assess and compare periodontal parameters and treatment needs in pregnant and non-pregnant women, with particular attention to trimester-specific variations.
MATERIALS AND METHODS
STUDY TYPE AND SETTING
This multicenter cross-sectional study was conducted at four national military hospitals in Kinshasa, Democratic Republic of the Congo, following Strengthening the Reporting of Observational Studies in Epidemiology guidelines.[19] From February to October 2023, 308 pregnant women attending prenatal clinics and 309 non-pregnant women from nearby military camps were recruited. The choice of these different selected hospitals was because the vast majority of pregnant women live in these different military camps where police officers or even their husbands are the body of this service, with easy access to the various prenatal centers. The free care of pregnant women allowed the examiners to follow up until delivery. The study protocol was approved by the Ethics Committee of the Public Health School, Kinshasa University, Faculty of Medicine (ESP/CE/87B/2025) and adhered to the Declaration of Helsinki. All participants provided written informed consent.
STUDY POPULATION
The study included pregnant women attending prenatal consultations and a control group of non-pregnant women. Inclusion criteria for the pregnant group were: confirmed pregnancy (by gonadotropin β-subunit levels in venous blood samples (20 mL) and ultrasound), age between 15 and 45 years, first trimester attendance (up to 12 weeks of amenorrhea), and informed consent. Non-pregnant women were eligible if they had reached menarche, consented to participate, and were mentally capable of answering questions. Exclusion criteria applied to both groups included: antibiotics during the past 3 months (n = 35), were receiving periodontal treatment (n = 59), wore dental prostheses (n = 22), had systemic diseases such as diabetes (n = 17), were smokers (n = 5), had presented at the stomatology department (n = 53), or had less than 20 functional teeth (n = 8); these women were excluded to avoid potential selection bias. After applying exclusion criteria and providing informed consent, 616 women participated in the study, including 307 pregnant and 309 non-pregnant women (adherence rate = 76%).
STUDY VARIABLES AND CLINICAL EXAMINATION
Data were collected through structured interviews and clinical oral examinations. Interview data included sociodemographic information (age, marital status, education level, occupation, and socioeconomic status), gestational age, and obstetric history.
Clinical examinations were performed by a calibrated examiner (EDK) using a dental chair, mirror, tweezers, a WHO periodontal probe, and appropriate lighting. The following periodontal indices were recorded: Oral Hygiene Index-Simplified (OHI-S),[20] BOP, Clinical attachment loss (CAL), and community periodontal index of treatment needs (CPITN).[21,22]
Examinations followed a standardized protocol starting from the disto-buccal surface of the maxillary right second molar, proceeding anteriorly and then to the opposite side, followed by the mandible. All fully erupted permanent teeth were examined, except for third molars, erupting, supernumerary, or partially impacted teeth. Measurements were recorded at six sites per tooth: mesiobuccal, midbuccal, disto-buccal, mesiolingual, midlingual, and distolingual. Periodontal pocket depth (PPD) was defined as the distance from the free gingival margin to the pocket base. A PCP-10 periodontal probe (Hu-Friedy, Chicago, IL) was used.
To ensure reliability, 30 patients were reexamined 1 h later by the same examiner. The intra-class correlation coefficients (κ) for PPD and CAL were 0.84 and 0.86, respectively.
Periodontal health was defined as PPD ≤ 3 mm and BOP < 10%. Gingivitis was classified as localized (BOP 10%–30%) or generalized (BOP ≥ 30%).[23] Trimesters were defined as follows: first (1st–12th week), second (13th–24th week), and third (25th–36th week) of amenorrhea.
DATA ANALYSIS
The collected data were analyzed using Statistical Package for the Social Sciences version 25.0 software (INM Corp., Armonk, NY, USA). Arithmetic means, frequencies, and the Chi-square test or Fisher’s exact test were used to compare the proportion of participants in each dental health category between the two groups, and the t test was used when appropriate to compare the mean of indices. Logistic regression identified factors associated with periodontal disease, with odds ratios and 95% confidence intervals (CI) used to assess the strength of association. The Bonferroni correction was applied to adjust for multiple comparisons. Statistical significance was set at P < 0.05.
RESULTS
A total of 616 women participated in the study, comprising 307 pregnant and 309 non-pregnant women. Baseline demographic characteristics—including age, education level, profession, and brushing frequency—were similar between the two groups, with no statistically significant differences except for socioeconomic status (P = 0.018) and marital status (P = 0.035); pregnant women were more likely to be married and of medium socioeconomic status [Table 1].
Table 1.
Basic characteristics of pregnant and non-pregnant women
| Variables | Total N = 616 (%) |
Pregnant N = 307 (%) |
Non-pregnant N = 309(%) |
P value2 |
|---|---|---|---|---|
| Age | 0.219 | |||
| [15-25] | 242 (39%) | 120 (39%) | 122 (39%) | |
| ]25-35] | 286 (46%) | 145 (47%) | 141 (46%) | |
| ]35-45] | 88 (14%) | 42 (14%) | 46 (15%) | |
| Level of education | 0.119 | |||
| Non in school | 9 (1.5%) | 4 (1.3%) | 5 (1.6%) | |
| Primary | 43 (7.0%) | 21 (6.8%) | 22 (7.1%) | |
| Secondary | 464 (75%) | 231 (75%) | 233 (75%) | |
| University | 100 (16%) | 51 (17%) | 49 (16%) | |
| Profession | 0.232 | |||
| Hairdreser | 2 (0.3%) | 1 (0.3%) | 1 (0.3%) | |
| merchant | 82 (13%) | 36 (12%) | 46 (15%) | |
| Dressmaker | 22 (3.6%) | 12 (3.9%) | 10 (3.2%) | |
| Teacher | 2 (0.3%) | 1 (0.3%) | 1 (0.3%) | |
| Beautician | 2 (0.3%) | 1 (0.3%) | 1 (0.3%) | |
| Student | 19 (3.1%) | 11 (3.6%) | 8 (2.6%) | |
| Housewife | 412 (67%) | 207 (67%) | 205 (66%) | |
| Functionary | 60 (9.7%) | 31 (10%) | 29 (9.4%) | |
| Nurse | 10 (1.6%) | 5 (1.6%) | 5 (1.6%) | |
| Doctor | 3 (0.5%) | 1 (0.3%) | 2 (0.6%) | |
| Musician | 2 (0.3%) | 1 (0.3%) | 1 (0.3%) | |
| Socio economic level | 0.018 | |||
| Low | 116 (19%) | 43 (14%) | 73 (24%) | |
| High | 11 (1.8%) | 5 (1.6%) | 6 (1.9%) | |
| Medium | 398 (65%) | 214 (70%) | 184 (60%) | |
| Medium high | 91 (15%) | 45 (15%) | 46 (15%) | |
| Civil status | 0.035 | |||
| Single | 228 (37%) | 101 (33%) | 127 (41%) | |
| Maried | 388 (63%) | 206 (67%) | 182 (59%) |
Pearson’s chi-squared test; Fisher’s exact test, N: total number of samples; %: percent
PERIODONTAL STATUS COMPARISON
Pregnant women demonstrated a significantly higher prevalence of periodontal pathology than their non-pregnant counterparts. Gingival BOP was more pronounced among pregnant women, with localized gingivitis (LG) reported in 35% and generalized gingivitis (GG) in 15%, compared to 31% and 12% in the control group, respectively [Table 2]. PPD > 4 mm was observed in 26% of pregnant women versus 19% of non-pregnant women (P = 0.049). CAL > 3 mm was also more frequent in pregnant women (9.8% vs. 6.5%); however, this difference was not statistically significant (P = 0.132) [Table 2].
Table 2.
Periodontal parameters in pregnant and non-pregnant women
| Variables | Average N (%) |
Pregnant N = 307 (%) |
Non-pregnant N = 309 (%) |
P value2 |
|---|---|---|---|---|
| BOP | 0.210 | |||
| GG | 83 (13%) | 47 (15%) | 36 (12%) | |
| GL | 203 (33%) | 106 (35%) | 97 (31%) | |
| Normal | 330 (54%) | 154 (50%) | 176 (57%) | |
| OHI-S | 0.221 | |||
| Good | 229 (37%) | 109 (36%) | 120 (39%) | |
| Bad | 143 (23%) | 83 (27%) | 60 (19%) | |
| Perfect | 20 (3.2%) | 10 (3.3%) | 10 (3.2%) | |
| Satisfactory | 224 (36%) | 105 (34%) | 119 (39%) | |
| PP | 0.049 | |||
| Inf to 4 mm | 476 (77%) | 227 (74%) | 249 (81%) | |
| Sup to 4 mm | 140 (23%) | 80 (26%) | 60 (19%) | |
| PA | 0.132 | |||
| Inf to 3 mm | 566 (92%) | 277 (90%) | 289 (94%) | |
| Sup to 3 mm | 50 (8.1%) | 30 (9.8%) | 20 (6.5%) | |
| CPITN | 0.013 | |||
| I | 151 (25%) | 72 (23%) | 79 (26%) | |
| II | 82 (13%) | 44 (14%) | 38 (12%) | |
| III | 138 (22%) | 81(26%) | 57(18%) | |
| IV | 4 (0.6%) | 4 (1.3%) | 0 (0%) |
OHI-S = oral hygiene index-simplified, BOP = bleeding on probing index, LG = localized gingivitis, GG = generalized gingivitis, PP = periodontal pocket depth, CAL = clinical attachment loss, CPITN = community periodontal index for treatment needs, N = total number of samples, % = percent.
Pearson’s chi-squared test; Fisher’s exact test
CPITN scores revealed that 26% of pregnant women required Treatment Need III (TNIII), significantly higher than the 18% among non-pregnant women (P = 0.013). CPITN grade IV (deep pockets) was observed only in pregnant women (1.3%) [Table 3].
Table 3.
Bleeding on probing (BOP) in pregnant women
| Variables | BOP | P value2 | |||
|---|---|---|---|---|---|
| GG, N = 47 (%) | LG, N = 106 (%) | Normal, N = 154 (%) | Average, N = 307(%) | ||
| OHI_S | 0.162 | ||||
| Good | 11 (23%) | 36 (34%) | 62 (40%) | 109 (36%) | |
| Bad | 23 (49%) | 29 (27%) | 31 (20%) | 83 (27%) | |
| Perfect | 1 (2.1%) | 1 (0.9%) | 8 (5.2%) | 10 (3.3%) | |
| Satisfy | 12 (26%) | 40 (38%) | 53 (34%) | 105 (34%) | |
| PP | 0.001 | ||||
| Inf to 4 | 27 (57%) | 73 (69%) | 127 (82%) | 227 (74%) | |
| Sup to 4 | 20 (43%) | 33 (31%) | 27 (18%) | 80 (26%) | |
| PA | 0.001 | ||||
| Inf 3 | 40 (85%) | 89 (84%) | 148 (96%) | 277 (90%) | |
| Sup 3 | 7 (15%) | 17 (16%) | 6 (3.9%) | 30 (9.8%) | |
| CPITN | 0.011 | ||||
| I | 18 (38%) | 53 (50%) | 1 (0.6%) | 72 (23%) | |
| II | 10 (21%) | 15 (14%) | 19 (12%) | 44 (14%) | |
| III | 19 (40%) | 33 (31%) | 29 (19%) | 81 (26%) | |
| IV | 0 (0%) | 3 (2.8%) | 1 (0.6%) | 4 (13%) | |
| 0 | 0 (0%) | 2 (1.9%) | 104 (68%) | 106 (35%) | |
OHI-S = oral hygiene index-simplified, BOP = bleeding on probing index, PP = periodontal pocket depth, CAL = clinical attachment loss, LG = localized gingivitis, GG = generalized gingivitis, CPITN = community periodontal index for treatment needs, N = total number of samples, % = percent.
Pearson’s chi-squared test; Fisher’s exact test
TRIMESTER-SPECIFIC TRENDS
A trimester-wise analysis revealed a progressive increase in periodontal disease severity as gestation advanced. LG peaked during the second trimester (13–24 weeks), affecting 50% of pregnant women, while periodontitis was most prevalent in the third trimester (>25 weeks), affecting 59% [Figures 1 and figure 2]. TNIII treatment need increased from 18% in the first trimester to 35% in the third trimester [Figure 3].
Figure 1.
Gingivitis and gestational age of pregnant women. 1 = first trimester, 2 = second trimester, 3 = third trimester
Figure 2.
Periodontitis and gestational age of pregnant women. 1 = first trimester, 2 = second trimester, 3 = third trimester, PP = periodontal pocket depth, PAC = clinical attachment loss
Figure 3.
Treatment needs by trimester
ASSOCIATION BETWEEN PERIODONTITIS AND CLINICAL PARAMETERS
In pregnant women, the severity of periodontitis (Stage II) was significantly associated with poor oral hygiene (OHI-S: 35%), GG (25%), and CPITN grade III (100%) [Table 4]. Among non-pregnant women, stage II periodontitis was less prevalent and primarily associated with LG (44%) and satisfactory oral hygiene (33%) [Table 5].
Table 4.
Severity of periodontitis and periodontal parameters in pregnant women
| Variables | Average N = 307(%) |
Wrong pocket N = 7(%) |
Stage 1 N = 229(%) |
Stage 2 N = 71(%) |
P value2 |
|---|---|---|---|---|---|
| BOP | 0.001 | ||||
| GG | 47 (15%) | 2 (29%) | 27 (12%) | 18 (25%) | |
| LG | 106 (35%) | 3 (43%) | 73 (32%) | 30 (42%) | |
| Normal | 154 (50%) | 2 (29%) | 129 (56%) | 23 (32%) | |
| OHI_S | 0.001 | ||||
| Good | 109 (36%) | 0 (0%) | 89 (39%) | 20 (28%) | |
| Bad | 83 (27%) | 5 (71%) | 53 (23%) | 25 (35%) | |
| Perfect | 10 (3.3%) | 1 (14%) | 4 (1.7%) | 5 (7.0%) | |
| Satisfactory | 105 (34%) | 1 (14%) | 83 (36%) | 21 (30%) | |
| CPITN | 0.001 | ||||
| I | 72 (23%) | 0 (0%) | 72 (31%) | 0 (0%) | |
| II | 44 (14%) | 1 (14%) | 43 (19%) | 0 (0%) | |
| III | 81 (26%) | 3 (43%) | 7 (3.1%) | 71 (100%) | |
| IV | 4 (1.3%) | 3 (43%) | 1 (0.4%) | 0 (0%) |
OHI-S = oral hygiene index-simplified, BOP = bleeding on probing index, LG = localized gingivitis, GG = generalized gingivitis, CAL = clinical attachment loss, CPITN = community periodontal index for treatment needs, N = total number of samples, % = percent.
Fisher’s exact test
Table 5.
Severity of periodontitis and periodontal parameters in non-pregnant women
| Variables | Average N = 307(%) |
Wrong pocket N = 35(%) |
Stage 1 N = 256(%) |
Stage 2 N = 18(%) |
P value2 |
|---|---|---|---|---|---|
| BOP | 0.001 | ||||
| GG | 34 (11%) | 8(23%) | 23 (8%) | 03 (17%) | |
| LG | 104 (34%) | 18 (51%) | 78 (30%) | 08 (44%) | |
| Normal | 171 (55%) | 9 (26%) | 155 (61%) | 07 (39%) | |
| OHI_S | 0.001 | ||||
| Good | 113 (36.5%) | 1 (2.8%) | 103 (40%) | 09 (50%) | |
| Bad | 59 (19%) | 20 (57%) | 39 (15%) | 00 (00%) | |
| Perfect | 11 (3.5%) | 3 (9%) | 5 (1.9%) | 3 (17%) | |
| Satisfactory | 126 (41%) | 11 (32%) | 109 (43%) | 06 (33%) | |
| CPTIN | 0.001 | ||||
| IV | 01 (0.3%) | 01 (3%) | 00 (0%) | 00 (0%) | |
| I | 80 (23%) | 01 (3%) | 77 (30%) | 02 (17%) | |
| II | 36 (12%) | 1 (3%) | 35 (14%) | 00 (00%) | |
| III | 53 (17%) | 32 (91%) | 07 (2.7%) | 14(78%) |
OHI-S = oral hygiene index-simplified, BOP = bleeding on probing index, LG = localized gingivitis, GG = generalized gingivitis, CAL = clinical attachment loss, CPITN = community periodontal index for treatment needs, N = total number of samples, % = percent.
Fisher’s exact test
PREDICTORS OF PERIODONTITIS
Multivariate logistic regression analysis [Table 6] indicated that marital status (being married) was independently associated with increased odds of periodontitis in pregnant women (OR = 2.87, 95% CI: 1.06–7.91, P = 0.038). No significant associations were found for age, trimester, or brushing frequency after adjusting for confounders.
Table 6.
Periodontitis and associated factors to the pregnant
| Variables | Descriptive Analysis | Bivaried analysis | Multivariate Analysis | |||||
|---|---|---|---|---|---|---|---|---|
| Exposed, N = 291 | Non exposed, N = 2781 | OR2 | 95% CI2 | P value | OR2 | 95% CI2 | P value | |
| Age | ||||||||
| [15-25] | 9 (31%) | 111 (40%) | – | – | – | – | ||
| ]25-35] | 19 (66%) | 126 (45%) | 0.54 | 0.22, 1.21 | 0.143 | 0.48 | 0.17, 1.25 | 0.142 |
| ]35-45] | 1 (3.4%) | 41 (15%) | 3.32 | 0.60, 62.3 | 0.321 | 2.30 | 0.36, 45.4 | 0.502 |
| Marital status | ||||||||
| Single | 13 (45%) | 88 (32%) | – | – | – | – | ||
| Married | 16 (55%) | 190 (68%) | 1.75 | 0.80, 3.80 | 0.201 | 2.87 | 1.06, 7.91 | 0.038 |
| Soc éco level | ||||||||
| low | 6 (21%) | 37 (13%) | – | – | – | – | ||
| High | 1 (3.4%) | 4 (1.4%) | 0.65 | 0.08, 13.8 | 0.371 | 0.08 | 0.00, 2.86 | 0.432 |
| Medium | 18 (62%) | 196 (71%) | 1.77 | 0.61, 4.53 | 0.233 | 0.95 | 0.27, 2.98 | 0.921 |
| Medium high | 4 (14%) | 41 (15%) | 1.66 | 0.44, 6.93 | 0.352 | 1.17 | 0.23, 6.27 | 0.906 |
| Trimester | ||||||||
| First trimester | 4 (14%) | 31 (11%) | — | — | — | — | ||
| Second trimester | 8 (28%) | 137 (49%) | 2.21 | 0.56, 7.50 | 0.212 | 2.09 | 0.49, 7.97 | 0.343 |
| Third trimester | 17 (59%) | 110 (40%) | 0.83 | 0.23, 2.45 | 0.801 | 0.70 | 0.18, 2.20 | 0.461 |
| Brushing frequency | ||||||||
| Once | 19 (66%) | 174 (63%) | – | – | – | – | ||
| Twice | 0 (0%) | 3 (1.1%) | 0.54 | 0.22, 6.63 | 0.921 | 0.15 | 0.24, 2.48 | 0.909 |
| Thrice folds | 10 (34%) | 101 (36%) | 1.10 | 0.50, 2.56 | 0.483 | 1.26 | 0.54, 3.12 | 0.604 |
OR = odds ratio, N = total number of samples, % = percent
DISCUSSION
Oral care is a critical component of prenatal health, with implications for both maternal and fetal outcomes. Despite its importance, no studies have examined trimester-specific changes in periodontal health. In the DRC, data comparing pregnant and non-pregnant women in this context are particularly limited.
Our subjects, both pregnant and non-pregnant, were similar to those found in other studies in terms of age, education level, and marital status.[24,25] However, some authors included women in an age range of 26–40 years.[26] The predominantly average socioeconomic status of this study’s subjects could be justified by the fact that the study site was located in an urban military hospital where the majority of patients’ husbands worked as civil servants and received a monthly salary. The frequency of dental brushing found in our study also corroborates with those of the other authors.[27,28] While studies have found that brushing more than 3 times a day was an effective preventor of periodontal disease,[29] other researchers found that 74% of pregnant women brushed once a day compared to 30% of non-pregnant women.[3,23] The variability of the frequency of dental brushing may be attributed to different cultural norms, the oral health policy of each country and region, and the involvement of researchers. Poor dental brushing technique during pregnancy has been shown to aggravate preexisting periodontal problems with an increased effect on the oral health of the mother as well as the unborn child.[30] Oral hygiene is a major asset for periodontal health in general and that of pregnant women in particular. Our results regarding oral hygiene are close to those of other authors, who observed that pregnant women had a significantly higher average OHI-S than non-pregnant women.[17] Pregnant women would benefit from regular stomatological consultations and maintaining appropriate oral hygiene. Effective control of supragingival plaque and improved toothbrushing habits have been shown to reduce the risk of periodontal disease in pregnant women.
Our findings regarding the periodontal parameters of pregnant and non-pregnant women differ from those reported in the previous studies. Some authors observed that both groups were similarly affected by GG, often associated with PPDs greater than 4 mm.[31] In contrast, other studies found that less than 45% of pregnant women exhibited GG, compared to more than 50% of non-pregnant women.[17] The incidence of deep periodontal pockets in pregnant women is believed to increase in response to elevated progesterone and estradiol levels during gestation. These hormonal changes promote vascular dilation in the gingival tissues, creating a favorable environment for the proliferation of periodontal pathogens. The simultaneous rise in estrogen levels and the plaque index (PI), particularly between the 13th and 25th weeks of amenorrhea, appears to significantly increase the risk of gingivitis compared to elevated PI alone. This suggests that hormonal fluctuations during pregnancy may amplify the inflammatory response to microbial plaque.[32] Moreover, increased levels of steroid hormones are known to alter the composition of subgingival calculus.[17] Specific changes in the oral biofilm, such as enrichment with anaerobic Gram-negative bacteria, are key contributors to the development of gingivitis. Typically, pregnancy-associated gingivitis emerges between the 13th and 32nd weeks of gestation, providing a rationale for initiating periodontal evaluations as early as the 12th week. The presence of dental biofilm in these cases indicates inadequate oral hygiene, reinforcing the need for preventive education and care during pregnancy.
During pregnancy, BOP was positively associated with PPDs ≥ 4 mm, showing a progressive increase that coincided with higher clinical attachment loss (CAL ≥ 4 mm) beginning around the 13th week of gestation. Scientific evidence suggests that hormonal fluctuations, particularly elevated levels of estrogen and progesterone beginning around the 12th week significantly influence periodontal tissues. Increased capillary permeability, largely driven by estrogen, predisposes pregnant women to gingival inflammation and bleeding.[11]
The presence of gestational gingivitis can also hinder effective tooth brushing and consistent oral hygiene practices. Together, these factors facilitate the accumulation of local irritants such as plaque and calculus, which further perpetuate periodontal inflammation. This mechanism is supported by other studies reporting that gingival inflammation intensifies during pregnancy even in the absence of an increase in biofilm quantity highlighting the role of altered host response.[33] Furthermore, the multifactorial nature of periodontitis is increasingly recognized, with strong associations established between chronic periodontal inflammation and systemic diseases. The bacterial load from periodontitis may trigger oxidative stress and increased production of nitric oxide (NO), contributing to systemic inflammatory responses. These effects are exacerbated in conditions such as cardiovascular disease and diabetes, which are characterized by elevated CRP levels.[34,35] Additional studies have found that periodontitis is linked to altered salivary NO levels, further supporting its systemic impact.[36]
A minority of pregnant women with periodontitis were between 25 and 35 years of age, whereas in the non-pregnant group, affected women were more commonly aged 35–45 years. Both groups shared similar characteristics, including a secondary level of education and a twice-daily toothbrushing routine—findings consistent with those reported by the previous studies.[21] Diego Prieto et al.[37] observed that 72.5% of pregnant women exhibited moderate to severe periodontitis, while only 27.5% had mild forms of the disease. Other studies have similarly reported higher periodontal index scores among pregnant women compared to their non-pregnant counterparts.[38]
Several factors may contribute to this elevated prevalence, including poor oral hygiene practices, unfavorable socioeconomic conditions, and limited access to periodontal care during pregnancy. In addition, as pregnancy progresses, the subgingival microbiota tends to shift toward a more anaerobic environment, further increasing susceptibility to periodontitis.
Interestingly, some South American studies have reported a lower prevalence of periodontal disease among pregnant women,[39] which contrasts with findings from other regions.[40] These discrepancies may reflect variations in population demographics, oral health behaviors, access to dental care, or methodological differences across studies.
The results are contradictory in terms of the severity and stage of periodontitis. Some authors found that 30.9% of pregnant women had moderate or severe periodontitis and 35.8% had stage II–IV periodontitis[41] compared to others who found only 5.5% had stage I periodontitis and 38.6% had stage II. In our study, periodontitis was significantly associated with married status among pregnant women. Some authors found gestational age associated with the risk of periodontitis in pregnant women, regardless of the women’s age.[42] To date, scientific evidence remains inconclusive regarding whether pregnancy is independently associated with an increased risk of periodontitis, gingivitis, or other clinical periodontal parameters.
The CPITN scores indicated a TNIII for pregnant women and treatment need 0 for non-pregnant women. Some authors have reported that the majority of both pregnant and non-pregnant women require periodontal treatment.[17] They also suggest that all pregnant women should receive oral hygiene education, noting that the need for complex treatment may decrease significantly from 48.4% during pregnancy to just 2.02% postpartum. In our study, treatment needs appeared largely unmet, as most participants had never visited a dentist. This highlights the urgent need to educate pregnant women about periodontal disease and to emphasize the importance of collaboration with dental professionals and multidisciplinary healthcare teams.
This study has certain limitations. It did not include a follow up assessment to evaluate postpartum periodontal recovery or investigate the efficacy of periodontal treatment during pregnancy. In addition, microbiological analyses could not be conducted due to the lack of laboratory infrastructure and technical expertise required for microbiome analysis. While a longitudinal study involving a larger cohort would offer more comprehensive insights, the current study was conducted with appropriate scientific rigor, and these limitations are unlikely to have significantly compromised the validity of our findings.
CONCLUSION
This multicenter cross-sectional study provides trimester-specific insight into the progression of periodontal health among pregnant women compared to non-pregnant controls. Our findings demonstrate a significant deterioration in periodontal parameters—including BOP, pocket depth, CAL, and CPITN-based treatment needs—particularly during the second and third trimesters of pregnancy. Notably, the prevalence of LG peaked in the second trimester, while periodontitis was most pronounced in the third trimester, with a corresponding increase in TNIII interventions.
These results support the hypothesis that pregnancy, mediated by hormonal and immunologic shifts, predisposes women to greater periodontal vulnerability. The association between marital status and increased periodontitis risk suggests that sociodemographic and behavioral factors may also influence oral health during gestation.
Given the established links between maternal periodontitis and adverse pregnancy outcomes, our findings underscore the urgent need to integrate periodontal screening, education, and preventive care into routine antenatal protocols, especially in resource-limited settings. Early identification and management of periodontal disease during pregnancy may contribute not only to improved oral health but also to better systemic and perinatal outcomes.
CONFLICTS OF INTEREST
There are no conflict of interest.
ETHICAL POLICY AND INSTITUTIONAL REVIEW BOARD STATEMENT
This study was approved by the ethics committee of the the Public Health School, Kinshasa University, Faculty of Medicine (ESP/CE/87B/2025,DRC).
PATIENT DECLARATION OF CONSENT
The written consents were taken before enrolling the participants into the study.
AUTHORS CONTRIBUTIONS
Not applicable.
DATA AVAILABILITY STATEMENT
Not applicable.
ACKNOWLEDGEMENT
Not applicable.
Funding Statement
Nil.
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