The proportion of GBS-positive mothers among the screened population and outcomes of maternal Group B streptococcus colonization at King Saud University Medical City: a retrospective cohort study
Nada Alayed, Hessah AlOthman, Ahmad Almalki, Kazi Nur Asfina, Najma Khalil, Ali Somily, Noor Faraj Alzahrani, Futoon Alsaleh, Layan Alhelal, Noyer Alshaibany, Ahmed Sherif Abdel Hamid Abdel Wahab, Mohamed AdelBACKGROUND:
Group B Streptococcus (GBS) is a leading cause of neonatal morbidity, preventable via intrapartum antibiotic prophylaxis (IAP).
OBJECTIVE:
To determine the proportion of GBS-positive mothers among the screened population, evaluate IAP protocol adherence, and identify clinical risk factors and outcomes.
DESIGN:
Single-center retrospective cohort study
SETTINGS:
Labor and Delivery Suite at King Saud University Medical City (KSUMC), Riyadh
PATIENTS AND METHODS:
Electronic medical records (July 2021–December 2022) were reviewed for pregnant women (≥35 weeks) who were screened or had GBS bacteriuria, along with their neonates. Multivariate logistic regression was used to determine risk factors.
MAIN OUTCOME MEASURES:
Proportion of GBS-positive mothers among the screened population, IAP timing, maternal febrile morbidity, neonatal intensive care unit (NICU) admissions, and culture-positive sepsis.
SAMPLE SIZE:
Of the 5292 deliveries, 688 unscreened elective cesareans were excluded, leaving 4604 screened women and 180 GBS-positive dyads.
RESULTS:
The proportion of GBS-positive mothers among the screened population was 3.91% (180/4604). Although 67.2% (121/180) of colonized women received IAP, only 15.6% (28/180) received it ≥4 hours before delivery. Maternal febrile morbidity was 0% (0/180). The neonatal intensive care unit (NICU) admission rate was 8.3% (15/180), and culture-positive neonatal sepsis occurred in 1.1% (2/180) of cases. GBS bacteriuria independently predicted adverse neonatal outcomes (aOR 2.35, 95% CI: 1.12–4.92,
CONCLUSIONS:
The proportion of GBS-positive mothers in the screened population is low (3.91%). While perinatal outcomes were generally excellent regardless of antibiotic timing, GBS bacteriuria was identified as a significant, independent predictor of adverse neonatal outcomes. These findings highlight a biologically plausible risk pathway that warrants validation in larger, multi-center prospective studies.