The association between bacteriuria and adverse pregnancy outcomes: a systematic review and meta-analysis of observational studies.

BACKGROUND: Antibiotics for bacteriuria and urinary tract infection are commonly prescribed during pregnancy to avoid adverse pregnancy outcomes. The aim of this study was to evaluate the association between significant bacteriuria in pregnancy and any of the four pregnancy outcomes: preterm delivery; low birth weight; small for gestational age; and preterm labour. METHODS: Systematic review with meta-analysis of observational studies. We searched PubMed, EMBASE, the Cochrane CENTRAL library, and Web of Science for observational studies published before 1 March 2022. The risk of bias was assessed using the Newcastle-Ottawa scale. Study identification, data extraction and risk-of-bias assessment was performed by two independent authors. We combined the included studies in meta-analyses and expressed results as ORs with 95% CIs (Prospero CRD42016053485). RESULTS: We identified 58 studies involving 421 657 women. The quality of the studies was mainly poor or fair. The pooled, unadjusted OR for the association between any significant bacteriuria and: (i) preterm delivery was 1.62 (95% CI: 1.30-2.01; 27 studies; I2 = 61%); (ii) low birth weight was 1.50 (95% CI: 1.30-1.72; 47 studies; I2 = 74%); (iii) preterm labour was 2.29 (95% CI: 1.53-3.43; 3 studies; I2 = 0%); and (iv) small for gestational age was 1.33 (95% CI: 0.88-2.02; 7 studies; I2 = 54%). Four studies provided an adjusted OR, but were too diverse to combine in meta-analysis. CONCLUSIONS: This systematic review identified an association between significant bacteriuria in pregnancy and the three complications: preterm delivery; low birth weight; and preterm labour. However, the quality of the available evidence is insufficient to conclude whether this association is merely due to confounding factors. There is a lack of high-quality evidence to support active identification and treatment of bacteriuria in pregnancy.

No effect of multi-strain probiotic supplementation on metabolic and inflammatory markers and newborn body composition in pregnant women with obesity: Results from a randomized, double-blind placebo-controlled study.

BACKGROUND AND AIMS: Modulation of the gut microbiome composition with probiotics may have beneficial metabolic effects in pregnant women with obesity. The aim was to investigate the effect of probiotic supplementation during pregnancy on metabolic and inflammatory markers and the body composition of the offspring. METHODS AND RESULTS: A randomized double-blind trial in 50 pregnant women (pre-pregnancy BMI ≥30 and < 35 kg/m2) comparing multi-strain probiotics (Vivomixx®; 450 billion CFU/d) versus placebo from 14 to 20 weeks of gestation until delivery was carried out. Participants were followed with two predelivery visits at gestational week 27-30 and 36-37 and with one postdelivery visit. All visits included fasting blood samples (C-reactive protein (CRP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), insulin, C-peptide, glucose, glucagon, and glucagon-like peptide-1 (GLP-1)). At delivery, umbilical cord blood samples were collected (GLP-1 and glucagon). At the postdelivery visit, a dual-energy X-ray absorptiometry (DXA) scan of the newborn was performed. Forty-nine of 50 participants completed the study until delivery, and 36 mother-offspring dyads underwent postdelivery examinations including a DXA scan. There were no significant differences in changes in measured biomarkers between the probiotic versus the placebo group. No differences were found in newborn body composition or GLP-1 and glucagon. GLP-1 measured in umbilical blood samples was positively correlated to fat percent in offspring from the probiotic group. CONCLUSION: In this study of pregnant women with obesity and their newborns, there was no effect of probiotic supplementation in mothers or babies on metabolic or inflammatory biomarkers or on body composition of offspring. This study was registered at clinicaltrials.gov as NCT02508844.