Non-Cochrane · aetiology · PM41583075
The role of oral dysbiosis in pregnancy complications: a systematic review and meta-analysis of preterm birth.
García-Rios Paula, Rodríguez-Lozano Francisco Javier, González-Murcia Raquel, et al. · Journal of oral microbiology · 2026 · PubMed · doi:10.1080/20002297.2026.2617757
Findings
Population Pregnant women
7 findings
| Preterm birth (PTB) group | Term birth (TB) group | Oral microbiome alpha diversity (Shannon index) Oral samples (saliva or subgingival plaque), 16S rRNA sequencing | MD 1.09 [-0.55, 2.73] GRADE not reported 4 studies · 296 participants |
| Preterm birth (PTB) group | Term birth (TB) group | Oral microbiome alpha diversity (Shannon index) Oral samples (saliva or subgingival plaque), 16S rRNA sequencing · Sample site: subgingival plaque | MD 2.02 [-1.1, 5.15] GRADE not reported 2 studies · 182 participants |
| Preterm birth (PTB) group | Term birth (TB) group | Oral microbiome alpha diversity (Shannon index) Oral samples (saliva or subgingival plaque), 16S rRNA sequencing · Sensitivity analysis: Wan et al. conversion of summary statistics | MD 1.07 [-0.48, 2.62] GRADE not reported 4 studies · 296 participants |
| Preterm birth (PTB) group | Term birth (TB) group | Oral microbiome alpha diversity (Shannon index) Oral samples (saliva or subgingival plaque), 16S rRNA sequencing · Geographic region: Asia | MD 0.28 [-0.00, 0.56] GRADE not reported 3 studies · 200 participants |
| Preterm birth (PTB) group | Term birth (TB) group | Oral microbiome alpha diversity (Shannon index) Oral samples (saliva or subgingival plaque), 16S rRNA sequencing · Sample site: saliva | MD 0.16 [-0.22, 0.53] GRADE not reported 2 studies · 114 participants |
| Preterm birth (PTB) group | Term birth (TB) group | Oral microbiome alpha diversity (Shannon index) Oral samples (saliva or subgingival plaque), 16S rRNA sequencing · Amplified 16S rRNA region: V3-V4 | MD 1.37 [-0.83, 3.57] GRADE not reported 3 studies · 242 participants |
| Preterm birth (PTB) group | Term birth (TB) group | Oral microbiome alpha diversity (Shannon index) Oral samples (saliva or subgingival plaque), 16S rRNA sequencing · Sensitivity analysis: Hozo et al. conversion of summary statistics | MD 0.98 [-0.43, 2.38] GRADE not reported 4 studies · 296 participants |
Included primary studies 41
Open in Studies| Study | Year | Also included by | Outcomes it informs here | Trial data |
|---|---|---|---|---|
| Alex 2024 Stress and mental health symptoms in early pregnancy are associated with the oral microbiome DOI:10.1136/bmjment-2024-301100 | 2024 | this review only | not stated | not extracted yet |
| Alex 2024 Stress and mental health symptoms in early pregnancy are associated with the oral microbiome. PMID:39562142 | 2024 | this review only | not stated | not extracted yet |
| Altemani 2022 Reduced Abundance of Nitrate-Reducing Bacteria in the Oral Microbiota of Women with Future Preeclampsia. PMID:35334796 | 2022 | this review only | not stated | not extracted yet |
| Azevedo 2025 Salivary proteome and microbiome in pregnancy and postpartum: An exploratory study on the relation with arterial hypertension DOI:10.1016/j.archoralbio.2025.106319 | 2025 | this review only | not stated | not extracted yet |
| Azevedo 2025 Salivary proteome and microbiome in pregnancy and postpartum: An exploratory study on the relation with arterial hypertension. PMID:40483843 | 2025 | this review only | not stated | not extracted yet |
| Benslimane 2024 Metabarcoding analysis of oral microbiome during pregnancy DOI:10.3389/fcimb.2024.1477703 | 2024 | this review only | not stated | not extracted yet |
| Benslimane 2024 Metabarcoding analysis of oral microbiome during pregnancy. PMID:39742335 | 2024 | this review only | not stated | not extracted yet |
| Geldenhuys 2022 Diversity of the gut, vaginal and oral microbiome among pregnant women in South Africa with and without pre-eclampsia DOI:10.3389/fgwh.2022.810673 | 2022 | this review only | not stated | not extracted yet |
| Geldenhuys 2022 Diversity of the gut, vaginal and oral microbiome among pregnant women in South Africa with and without pre-eclampsia. PMID:36188424 | 2022 | this review only | not stated | not extracted yet |
| Gilbert Klaczko 2023 The Oral Microbiome and Cross-Kingdom Interactions during Pregnancy DOI:10.1177/00220345231176459 | 2023 | this review only | not stated | not extracted yet |
| Gilbert Klaczko 2023 The Oral Microbiome and Cross-Kingdom Interactions during Pregnancy. PMID:37431832 | 2023 | this review only | not stated | not extracted yet |
| Hong 2023 Predicting preterm birth using machine learning techniques in oral microbiome DOI:10.1038/s41598-023-48466-x | 2023 | this review only | not stated | not extracted yet |
| Hong 2023 Predicting preterm birth using machine learning techniques in oral microbiome. PMID:38036587 | 2023 | this review only | not stated | not extracted yet |
| La 2022 Profile of the oral microbiota from preconception to the third trimester of pregnancy and its association with oral hygiene practices DOI:10.1080/20002297.2022.2053389 | 2022 | this review only | not stated | not extracted yet |
| La 2022 Profile of the oral microbiota from preconception to the third trimester of pregnancy and its association with oral hygiene practices. PMID:35341210 | 2022 | this review only | not stated | not extracted yet |
| Li 2021 The oral microbiome of pregnant women facilitates gestational diabetes discrimination DOI:10.1016/j.jgg.2020.11.006 | 2021 | this review only | not stated | not extracted yet |
| Li 2021 The oral microbiome of pregnant women facilitates gestational diabetes discrimination. PMID:33663937 | 2021 | this review only | not stated | not extracted yet |
| Lin 2018 Ecological Shifts of Supragingival Microbiota in Association with Pregnancy DOI:10.3389/fcimb.2018.00024 | 2018 | this review only | not stated | not extracted yet |
| Lin 2018 Ecological Shifts of Supragingival Microbiota in Association with Pregnancy. PMID:29497601 | 2018 | this review only | not stated | not extracted yet |
| Liu 2024 (low birth weight) Can oral microbiome predict low birth weight infant delivery? DOI:10.1016/j.jdent.2024.105018 | 2024 | this review only | Oral microbiome alpha diversity (Shannon index) | not extracted yet |
| Liu 2025 (pregnancy loss) Oral microbiome dysbiosis in women with a history of pregnancy loss: a metagenomic cross-sectional study DOI:10.1038/s41598-025-09071-2 | 2025 | this review only | not stated | not extracted yet |
| Liu L 2025 Oral microbiome dysbiosis in women with a history of pregnancy loss: a metagenomic cross-sectional study. PMID:40624115 | 2025 | this review only | not stated | not extracted yet |
| Liu P 2024 Can oral microbiome predict low birth weight infant delivery? PMID:38679133 | 2024 | this review only | Oral microbiome alpha diversity (Shannon index) | not extracted yet |
| Ma 2025 Comparative analysis of oral, placental, and gut microbiota characteristics, functional features and microbial networks in healthy… DOI:10.1016/j.jri.2025.104535 | 2025 | this review only | not stated | not extracted yet |
| Ma 2025 Comparative analysis of oral, placental, and gut microbiota characteristics, functional features and microbial networks in healthy… PMID:40315739 | 2025 | this review only | not stated | not extracted yet |
| Meric 2023 Clinical, oral immunological and microbiological shifts during and after pregnancy DOI:10.1007/s00784-023-05408-1 | 2023 | this review only | not stated | not extracted yet |
| Meric 2023 Clinical, oral immunological and microbiological shifts during and after pregnancy. PMID:38157038 | 2023 | this review only | not stated | not extracted yet |
| Park 2024 Differences in maternal subgingival microbiome between preterm and term births: The MOHEPI study DOI:10.1111/jre.13292 | 2024 | this review only | Oral microbiome alpha diversity (Shannon index) | not extracted yet |
| Park 2024 Differences in maternal subgingival microbiome between preterm and term births: The MOHEPI study. PMID:38808521 | 2024 | this review only | Oral microbiome alpha diversity (Shannon index) | not extracted yet |
| Saadaoui 2024 Exploring the composition of placental microbiome and its potential origin in preterm birth DOI:10.3389/fcimb.2024.1486409 | 2025 | this review only | Oral microbiome alpha diversity (Shannon index) | not extracted yet |
| Saadaoui 2024 Exploring the composition of placental microbiome and its potential origin in preterm birth. PMID:39885963 | 2024 | this review only | Oral microbiome alpha diversity (Shannon index) | not extracted yet |
| Vidmar Simic 2023 Oral microbiome and preterm birth DOI:10.3389/fmed.2023.1177990 | 2023 | this review only | not stated | not extracted yet |
| Vidmar Simic 2023 Oral microbiome and preterm birth. PMID:37608830 | 2023 | this review only | not stated | not extracted yet |
| Xu 2020 Differential intestinal and oral microbiota features associated with gestational diabetes and maternal inflammation DOI:10.1152/ajpendo.00266.2019 | 2020 | this review only | not stated | not extracted yet |
| Xu 2020 Differential intestinal and oral microbiota features associated with gestational diabetes and maternal inflammation. PMID:31891538 | 2020 | this review only | not stated | not extracted yet |
| Yang 2022 Subgingival Microbiome in Pregnancy and a Potential Relationship to Early Term Birth DOI:10.3389/fcimb.2022.873683 | 2022 | this review only | Oral microbiome alpha diversity (Shannon index) | not extracted yet |
| Yang 2024 (placental immunity) The influence of the oral microbiota in full-term pregnant women on immune regulation during pregnancy DOI:10.1016/j.jri.2024.104298 | 2024 | this review only | not stated | not extracted yet |
| Yang I 2022 Subgingival Microbiome in Pregnancy and a Potential Relationship to Early Term Birth. PMID:35646730 | 2022 | this review only | Oral microbiome alpha diversity (Shannon index) | not extracted yet |
| Yang P 2024 The influence of the oral microbiota in full-term pregnant women on immune regulation during pregnancy. PMID:39002425 | 2024 | this review only | not stated | not extracted yet |
| Yao 2019 Gestational diabetes mellitus increases the detection rate and the number of oral bacteria in pregnant women DOI:10.1097/md.0000000000014903 | 2019 | this review only | not stated | not extracted yet |
| Yao 2019 Gestational diabetes mellitus increases the detection rate and the number of oral bacteria in pregnant women. PMID:30882709 | 2019 | this review only | not stated | not extracted yet |
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Pregnant women | Pregnant women (n=11 to 375 per study) (n=21 studies) |
| Intervention | Presence of oral dysbiosis (alpha/beta diversity, taxa abundance) | Oral dysbiosis by 16S rRNA sequencing (saliva, supragingival or subgingival plaque) |
| Comparison | Pregnant women in healthy conditions | Healthy, term-birth or normotensive pregnant women |
| Outcomes | Preeclampsia, gestational diabetes, preterm birth, low birth weight, mental health, immune regulation, pregnancy loss; meta-analysis: Shannon index PTB vs TB | Gestational diabetes, preeclampsia, preterm birth, low birth weight, stress/immune, pregnancy loss; pooled Shannon index PTB vs TB MD 1.09 (-0.554 to 2.73) (n=4) |
| Study designs | Observational studies (cross-sectional, case-control, cohort) and clinical trials, 2015-2025, English or Spanish | 7 to 8 cohort, 8 case-control, 4 to 5 cross-sectional studies (n=21) |
| Timing | Not specified | Not specified |