Summary: A large Danish cohort study found reassuring evidence that common maternal infections during pregnancy — and the typical antibiotic treatments used — are not associated with measurable declines in children’s later cognitive abilities or school performance. Researchers compared school exam results and intelligence test scores for more than 270,000 children with maternal health records documenting infections and antimicrobial prescriptions during pregnancy.
Across multiple analyses, including comparisons between full siblings to account for shared genetics and family environment, the study did not find meaningful differences in academic grades or intelligence measures linked to maternal infections or use of systemic antimicrobials while pregnant.
Key facts
- No detectable cognitive impact: Maternal infections and prescribed systemic antimicrobials during pregnancy were not linked to worse outcomes in 9th-grade language and math grades or in intelligence test scores used for military conscription.
- Sibling comparisons strengthen the results: Analyses that compared full siblings controlled for many genetic and household-level influences and produced consistent null findings.
- Clinical caution remains: Prompt diagnosis and treatment of infections during pregnancy remain essential because untreated or severe infections can increase the risk of obstetric complications such as preterm birth.
Source: Neuroscience News
Expectant parents commonly worry that infections or medications during pregnancy could harm the developing brain. This extensive population study from Denmark provides evidence that common bacterial infections — examples cited include urinary tract infections and pneumonia — and the routine antimicrobial treatments used for them do not appear to produce long-term deficits in children’s cognition or school achievement.
Published in PLOS Medicine, the analysis used national registry data covering children born in Denmark from 1996 through 2003. The investigators linked maternal records of filled prescriptions for systemic antimicrobials at community pharmacies and hospital admissions for infections with later academic outcomes — standardized grades in language and mathematics at the end of compulsory schooling — and with intelligence test scores (expressed as IQ) available for a nested group of young men assessed during military conscription.
Among the 274,166 children in the sibling cohort, nearly 30% (80,817) had mothers who filled at least one prescription for a systemic antimicrobial during pregnancy; a smaller group (5,628, or 2.1%) had mothers who were hospitalized for an infection while pregnant. When the researchers adjusted for family-level factors by comparing full siblings, they observed no consistent differences in school grades or IQ tied to maternal antimicrobial prescriptions or inpatient infection records. Results were similar when exposure windows during gestation were analyzed in two-week intervals.
The lead investigators summarized the findings by noting that common infections and their typical antibiotic treatments did not show evidence of harming fetal brain development in these measures. The sibling-based design is a strong feature of the study because it helps remove confounding from stable family characteristics such as parental education, socioeconomic status, and genetic background — factors that can otherwise bias associations in population studies.
Nonetheless, the authors and clinical experts emphasize that these reassuring findings do not mean infections during pregnancy should be ignored. Severe or untreated infections can still lead to adverse pregnancy outcomes, including preterm birth and other complications, and women who experience symptoms of infection should seek medical care so that appropriate treatment can be provided.
The study’s strengths include its large, population-based sample size and long-term follow-up using comprehensive registry data. Key limitations noted by the researchers include the lack of detailed in-hospital pharmaceutical records and limited information on the specific pathogens responsible for hospital-treated infections, which could affect interpretation of certain clinical scenarios.
Overall, this research offers important reassurance for pregnant women and their healthcare providers: in this large Danish cohort, common bacterial infections and the commonly prescribed antimicrobials used to treat them were not associated with measurable long-term cognitive harm in offspring. The findings support current clinical practice emphasizing timely diagnosis and treatment of maternal infections to protect both maternal and fetal health.
Funding: The study was a collaboration between the Statens Serum Institut and the Danish Cancer Society, with support from the Lundbeck Foundation and the Health Foundation.
About this pregnancy and brain development research news
Author: Neuroscience News Communications
Source: Neuroscience News Communications
Contact: Neuroscience News Communications – Neuroscience News
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Original research (open access): “Maternal infections during pregnancy and offspring cognitive outcome: A nationwide full-sibling cohort study” by Anders Husby et al., PLOS Medicine. DOI: 10.1371/journal.pmed.1004657
Abstract
Maternal infections during pregnancy and offspring cognitive outcome: A nationwide full-sibling cohort study
Background
Maternal infections are common in pregnancy, but prior studies have produced mixed findings about their potential effects on offspring cognition. Using long-term follow-up of a nationwide sibling cohort in Denmark, with linked information on community antimicrobial prescriptions and inpatient hospitalizations for infection, the investigators set out to estimate associations between maternal infections during pregnancy and later school grades and intelligence test results in adolescence.
Methods and findings
The researchers defined a cohort of full siblings born between January 1, 1996 and December 31, 2003, from national registries and linked these births to maternal filled prescriptions for antimicrobial drugs and to hospital records for infections during pregnancy. Outcomes were standardized examination grades in language and mathematics at the end of compulsory schooling, and IQ scores from military conscription records for a nested sub-cohort of full brothers.
Of 274,166 children in the sibling cohort, 80,817 (29.5%) had mothers who filled at least one systemic antimicrobial prescription during pregnancy, while 5,628 (2.1%) had mothers hospitalized for infection during pregnancy. After accounting for shared family factors in sibling comparisons, the study found no consistent differences in language or mathematics grades or in IQ associated with maternal antimicrobial prescriptions or inpatient infections. Some associations that appeared in analyses that did not account for shared family factors were attenuated when siblings were compared, supporting the importance of controlling for family-level confounding. The study noted similar null results when examining bi-weekly exposure periods during gestation.
Main study limitations include the absence of in-hospital pharmaceutical prescription records and limited information on the specific pathogens responsible for infections.
Conclusions
The authors conclude that common maternal infections during pregnancy do not appear to have major effects on offspring cognitive outcomes and that commonly prescribed antimicrobials during pregnancy are not associated with adverse long-term cognitive outcomes in this large, population-based sibling cohort.