The effect of Helicobacter pylori infection on pregnancy and fetal complications: a systematic review and meta-analysis.

BACKGROUND

The association between Helicobacter pylori infection and adverse pregnancy outcomes has remained uncertain due to heterogeneous diagnostic approaches. A systematic review and meta-analysis was therefore conducted to quantify associations between maternal H. pylori and pregnancy outcomes such as preeclampsia, gestational diabetes mellitus (GDM), hyperemesis gravidarum (HG), preterm birth, and small for gestational age (SGA), alongside appraising consistency across key methodological strata.

METHODS

Observational cohort and case-control studies were identified in various online databases to September 2025 following PRISMA 2020. Exposure was determined by serology, urea breath test, stool antigen testing, molecular assays, or mixed strategies. Study quality was evaluated using the Newcastle-Ottawa Scale. Effect estimates were pooled as risk ratios (RRs) using fixed-effect models upon low heterogeneity and random-effects (REML) models otherwise. Small-study effects and robustness were explored using funnel plots, Egger's test, and leave-one-out analyses, with predefined subgroup analyses by diagnostic method, region, design, and quality.

RESULTS

From 1,998 records, 25 studies were included. H. pylori infection was associated with higher risks of preeclampsia (RR 2.06, 95% CI 1.42-3.01), GDM (RR 1.42, 95% CI 1.00-2.03), Hyperemesis gravidarum (RR 5.57, 95% CI 3.43-9.04), preterm birth (RR 1.30, 95% CI 1.14-1.49), and Small for gestational age (RR 1.18, 95% CI 1.03-1.36). Evidence of small-study effects was observed for several outcomes. Subgroup analyses suggested stronger associations with serologic and stool antigen assessments, but effect directionality remained consistent across strata. The evidence base consisted entirely of observational studies, and substantial between-study heterogeneity and small-study effects were observed for several outcomes.

CONCLUSIONS

Maternal H. pylori infection was found to be associated with increased risks of HG, preeclampsia, GDM, preterm birth, and SGA; however, given the observational evidence base, heterogeneity, and small-study effects, these findings should be interpreted as exploratory and hypothesis-generating. The current evidence does not support routine screening or eradication during pregnancy, and any potential clinical implications remain speculative pending large, methodologically robust prospective studies and randomized trials with standardized exposure ascertainment and rigorous control of confounding.

REGISTRATION: PROSPERO CRD420251152286.