🟠 Moderate Evidence
A large population-based cohort study published in PLOS Medicine has identified increased risks of neurodevelopmental disorders in children born via vacuum-assisted delivery (VAD), particularly when the procedure is performed at higher fetal head stations. The study, conducted by researchers including Dr. Ida Björk and colleagues at Swedish medical institutions, followed 630,985 term singleton births from 1997 to 2014 with median follow-up of 13–14 years through December 2021.
Key takeaways
- Mid/low vacuum-assisted delivery was associated with 7.20 times higher odds of traumatic intracranial hemorrhage compared to emergency cesarean delivery
- Children born via VAD showed increased hazard ratios for autism spectrum disorder, ADHD, and other neurodevelopmental conditions during long-term follow-up
- Risks varied significantly by fetal head station, with higher stations associated with greater adverse outcomes
- Findings suggest careful selection criteria and consideration of alternative delivery methods when VAD is contemplated at higher head stations
Study at a Glance
| Source | PLOS Medicine |
| Study type | Population-based cohort study with prospective long-term follow-up |
| Sample size | 630,985 singleton births |
| Population | Primiparous women; term singleton births in Sweden |
| Country | Sweden |
| Follow-up period | 13–14 years median (through December 2021) |
Neonatal Intracranial Hemorrhage Risk by Delivery Mode
Odds ratios compared to emergency cesarean delivery (baseline). Swedish cohort, 1997–2014.
Source: Björk et al., PLOS Medicine, 2024 | Georgian Medical Journal News
Neonatal hemorrhage risks elevated across all VAD head stations
Compared with emergency cesarean delivery (ECD), mid/low vacuum-assisted delivery was associated with a traumatic intracranial hemorrhage (ICH) odds ratio of 7.20 (95% confidence interval 2.97–17.45), and a non-traumatic ICH odds ratio of 3.65 (95% CI 2.41–5.50), according to the study published in PLOS Medicine. The analysis, which adjusted for maternal age, body mass index, gestational age, pre-eclampsia, gestational diabetes, and diabetes mellitus type I/II, demonstrated that even high-station VAD carried elevated hemorrhage risk compared to ECD.
The researchers, led by Dr. Ida Björk and colleagues at Swedish obstetric and pediatric centres, examined nationwide health register data spanning 1997 to 2014 and followed all children for adverse neurodevelopmental diagnoses through December 2021. The median follow-up period was 13–14 years. The cohort included all singleton births to primiparous women in Sweden, providing robust epidemiological power to detect long-term sequelae.
Long-term neurodevelopmental disorders elevated after VAD
Beyond neonatal outcomes, the longitudinal analysis revealed increased hazard ratios for multiple neurodevelopmental conditions in the VAD-exposed cohort. Using multivariable Cox regression models to estimate time-to-diagnosis hazard ratios, the study found elevated risk of autism spectrum disorder (ASD), attention deficit/hyperactivity disorder (ADHD), cerebral palsy (CP), epilepsy (EP), and intellectual disability (ID) in children born via VAD compared to those delivered via ECD or spontaneous vaginal delivery.
These long-term analyses were additionally adjusted for maternal smoking status, child’s birth year, chorioamnionitis, maternal education level, and maternal psychiatric comorbidity—factors that could confound associations between delivery mode and neurodevelopmental diagnosis. The stratification by child sex allowed for detection of potential sex-specific effects, a methodological strength that addresses known variations in neurodevelopmental disorder prevalence between boys and girls.
Critically, the study compared outcomes across three reference groups: ECD, high-station VAD, and mid/low-station VAD, stratified by head station at initiation of the procedure. This granular stratification revealed that the fetal head station at the time of vacuum application was a significant effect modifier—procedures attempted at higher stations (closer to the pelvic outlet) appeared to carry lower absolute risk than those at mid/low stations, although all VAD categories showed elevated risk relative to spontaneous vaginal delivery.
Clinical implications for obstetric practice and patient counselling
The findings align with growing concern about operative vaginal delivery safety documented in recent guidelines from the American College of Obstetricians and Gynaecologists (ACOG) and the Royal College of Obstetricians and Gynaecologists (RCOG). Both organizations recommend careful patient selection, operator experience, and low threshold for conversion to cesarean delivery if progress is not achieved. The Swedish study provides population-level evidence supporting these recommendations by demonstrating that VAD—even in contemporary settings with modern safety protocols—carries measurable long-term neurodevelopmental risk.
For individual clinical practice, these findings suggest that informed consent discussions with pregnant individuals should explicitly include the potential for long-term neurodevelopmental sequelae, not merely immediate neonatal injury. The risk quantification provided by this cohort study—derived from a universal healthcare system with standardized delivery protocols—offers clinically relevant numbers for shared decision-making. Links to Clinical Updates and Quality & Safety resources can support clinicians in updating practice frameworks.
Mid/low vacuum-assisted delivery was associated with a 7.20-fold increase in traumatic intracranial hemorrhage and elevated long-term risk of autism spectrum disorder, ADHD, and other neurodevelopmental conditions compared to emergency cesarean delivery in a Swedish population cohort of 630,985 births.
— Dr. Ida Björk and colleagues, Swedish medical institutions (PLOS Medicine, 2024)
What this means
Frequently asked questions
Does this study mean vacuum delivery is unsafe?
No. The study compares vacuum-assisted delivery to emergency cesarean delivery and spontaneous vaginal delivery, but does not establish whether VAD itself is unsafe in absolute terms or compared to routine elective cesarean. Rather, it quantifies previously uncertain long-term risks and suggests that the risk-benefit calculation warrants careful consideration. VAD can be appropriate when performed by experienced operators on carefully selected candidates, but this evidence suggests lower threshold for conversion to cesarean if progress stalls.
What is fetal head station and why does it matter in this study?
Fetal head station describes the position of the baby’s head in the birth canal, measured in centimeters relative to a fixed anatomical landmark (the ischial spines). High-station deliveries (closer to the outlet) are generally considered lower-risk than mid/low-station deliveries (higher in the pelvis, requiring greater traction and duration). This study found that VAD at mid/low stations carried higher neonatal hemorrhage risk than high-station VAD, suggesting that head position at initiation of the procedure is a critical safety factor.
How long were children followed, and are these outcomes permanent?
The median follow-up was 13–14 years (range varies by birth year and outcome definition). The study captured diagnoses of ADHD, autism, cerebral palsy, epilepsy, and intellectual disability recorded in national health registers during this period. This does not mean all outcomes are permanent or irreversible—many neurodevelopmental diagnoses are subject to intervention, therapy, and educational support. However, the earlier age of diagnosis in VAD-exposed children suggests greater disease burden or clinical severity.
The Swedish population cohort study published in PLOS Medicine will likely influence international obstetric practice guidelines and clinical decision-making regarding operative vaginal delivery in high-income settings. Future research should examine whether the elevated risks persist in contemporary cohorts using modern vacuum devices and standardized safety protocols, and whether outcomes differ in multiparious women (who were excluded from this analysis). Clinical implementation of these findings should emphasize personalized risk counselling and selective, evidence-based use of operative vaginal delivery.
Source: Vacuum-Assisted Delivery and Long-Term Neurodevelopmental Outcomes: A Population-Based Cohort Study, PLOS Medicine, 2024
Was this article helpful?
Related Coverage
