---
title: "Long-Term Neurodevelopmental Outcomes Following Vacuum-Assisted Delivery: A Swedish Cohort Study"
id: "plos-medicine-1-long-term-neurodevelopmental-outcomes-after-vacuum-assisted-delivery-a"
canonical_url: "https://medichelpline.com/clinical-feed/plos-medicine-1-long-term-neurodevelopmental-outcomes-after-vacuum-assisted-delivery-a"
content_type: "clinical_feed_article"
specialty: "Pediatrics"
source_name: "PLOS Medicine"
source_url: "https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1004825"
published_at: "2026-07-17T14:00:00.000Z"
evidence_level: "Journal Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Long-Term Neurodevelopmental Outcomes Following Vacuum-Assisted Delivery: A Swedish Cohort Study
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/plos-medicine-1-long-term-neurodevelopmental-outcomes-after-vacuum-assisted-delivery-a
- **Specialty:** [Pediatrics](https://medichelpline.com/clinical-feed/pediatrics.md)
- **Primary Source:** PLOS Medicine
- **Source URL:** [Original Journal Publication](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1004825)
- **Published At:** 2026-07-17T14:00:00.000Z
- **Evidence Rating:** Journal Feed
## Executive GIST (TL;DR)
- Vacuum-assisted delivery (VAD) is commonly used in obstetrics, but concerns exist about its long-term neurodevelopmental effects, especially for procedures done at mid/low fetal head stations. - This large Swedish population-based cohort study followed over 630,000 term singleton births to primiparous women from 1997 to 2014, with follow-up data through 2021. - Neonatal complications such as intracranial hemorrhage, subgaleal hematoma, and seizures were more frequent after mid/low VAD compared with emergency cesarean delivery (ECD). - Outlet VAD was associated with fewer adverse neonatal outcomes, similar to spontaneous vaginal delivery, when compared with ECD. - Long-term follow-up showed no increased risk of neurodevelopmental disorders (ADHD, ASD, CP, epilepsy) after mid/low VAD relative to ECD, and outlet VAD showed lower risk of intellectual disability. - The study adjusted for multiple maternal and neonatal risk factors and stratified analyses by fetal head station and child sex. - Limitations included lack of detailed clinical indication for interventions and timing of cesarean in labor stages. - Findings support the overall long-term safety of VAD with appropriate use, addressing an important knowledge gap in obstetric care.
## Clinical Analysis & Structured Key Points
SKIP TO MAIN CONTENT Advertisement plos.org Create account Sign in About Browse Publish advanced search 0 Save 0 Citation 32 View 0 Share OPEN ACCESS PEER-REVIEWED RESEARCH ARTICLE Long-term neurodevelopmental outcomes after vacuum-assisted delivery: A population-based cohort study Ida Björk , Jenny Bolk, Gunilla Ajne, Ängla Mantel Published: July 17, 2026 https://doi.org/10.1371/journal.pmed.1004825 Article Authors Metrics Comments Media Coverage Abstract Author summary Introduction Methods Results Discussion Supporting information Acknowledgments References Reader Comments Figures ? This is an uncorrected proof. Abstract Background Vacuum-assisted delivery (VAD) is widely used in obstetric care, yet concerns remain regarding potential long-term neurodevelopmental sequelae in offspring, particularly after procedures performed at higher fetal head stations. Evidence on long-term outcomes after VAD remains limited. Given the safety concerns surrounding VAD, we investigated neonatal and long-term neurodevelopmental outcomes after VAD stratified by fetal head station, using emergency cesarean delivery (ECD) and spontaneous vaginal delivery as reference groups. Methods and findings In this population-based cohort study, we obtained data from nationwide health registers and included all singleton births to primiparous women in Sweden between 1997 and 2014, with follow-up through December 31, 2021. Differences in neonatal outcomes across delivery modes were estimated using multivariable logistic regression models to obtain odds ratios (ORs). All children were followed longitudinally for adverse long-term neurodevelopmental outcomes—a diagnosis of attention deficit/hyperactivity disorder [ADHD], autism spectrum disorder [ASD], cerebral palsy [CP], epilepsy [EP], or intellectual disability [ID]. Rates of long-term outcomes were compared using multivariable Cox regression models to obtain hazard ratios (HRs). All analyses were stratified by child sex. Analyses of neonatal outcomes were adjusted for maternal age, body mass index (BMI), gestational age, pre-eclampsia, gestational diabetes, and diabetes mellitus type I/II. Long-term analyses were additionally adjusted for smoking status, child’s birth year, chorioamnionitis, maternal education level, and maternal psychiatric comorbidity. Among 630,985 term singleton births, median follow-up was 13–14 years. Compared with ECD, mid/low VAD was associated with increased odds of neonatal intracranial hemorrhage (traumatic aOR 7.20, 95% CI [2.97, 17.45]; non-traumatic aOR 3.65, 95% CI [2.41, 5.52]; subgaleal hematoma aOR 3.35, 95% CI [2.68, 4.20]; and neonatal seizures aOR 1.85, 95% CI [1.52, 2.26]), but with lower odds of meconium aspiration (aOR 0.53, 95% CI [0.42, 0.67]). In long-term follow-up, mid/low VAD showed no increased risks for ADHD, ASD, CP, or epilepsy, and a reduced risk of intellectual disability (aHR 0.80, 95% CI [0.67, 0.96]) as compared with ECD. Outlet VAD—similar to spontaneous vaginal delivery—was associated with lower risks of adverse neonatal and long-term neurodevelopmental outcomes compared with ECD. The main limitations of this study were the lack of information on the indication for intervention and whether emergency cesarean deliveries were performed in the first or second stage of labor. Conclusions In this nationwide cohort, mid/low VAD was associated with higher neonatal morbidity but no increased risk of long-term neurodevelopmental disorders. Outlet VAD showed no signal of adverse long-term neurodevelopmental outcomes. These findings provide reassuring evidence regarding the long-term safety of VAD when performed appropriately and help address an important knowledge gap regarding long-term outcomes after VAD. However, comparisons between delivery modes should be interpreted cautiously, as the clinical circumstances leading to VAD and ECD differ and are incompletely captured in register data. The findings should therefore not be interpreted as evidence to guide acute choice of delivery mode. Author summary Why was this study done? Despite widespread use of vacuum-assisted delivery (VAD), concerns remain regarding possible long-term neurodevelopmental consequences for children, particularly after procedures performed at higher fetal head stations. Existing evidence on long-term outcomes after VAD is limited, and few studies have distinguished between outlet and mid/low procedures. We therefore investigated neonatal and long-term neurodevelopmental outcomes after VAD, stratified by fetal head stations, in a large nationwide cohort. What did the researchers do and find? We used nationwide Swedish registry data including more than 600,000 births and followed the children for up to 24 years. We studied both short-term neonatal outcomes and long-term neurodevelopmental disorders after VAD, distinguishing between outlet and mid/low VAD. Children born after outlet VAD had lower risks of attention-deficit/hyperactivity disorder, autism spectrum disorder, intellectual disability, and epilepsy when compared to children born after emergency cesarean delivery. Mid/low VAD was not linked to increased long-term risks, although some neonatal complications were more frequent. What do these findings mean? These findings provide reassuring evidence regarding the long-term safety of VAD when performed appropriately. Although some neonatal complications were more frequent after mid/low VAD, these risks did not appear to translate into increased long-term neurodevelopmental morbidity. Because the clinical circumstances leading to VAD and emergency cesarean delivery differ and are incompletely captured in register data, these findings should not be interpreted as evidence to guide acute choice of delivery mode. Rather, they help address an important knowledge gap regarding the long-term safety of VAD. A limitation of this study is that information on why an intervention was performed and whether emergency cesarean deliveries occurred before or after full cervical dilatation was not available, making some comparisons between delivery modes difficult to interpret. Figures Citation: Björk I, Bolk J, Ajne G, Mantel Ä (2026) Long-term neurodevelopmental outcomes after vacuum-assisted delivery: A population-based cohort study. PLoS Med 23(7): e1004825. https://doi.org/10.1371/journal.pmed.1004825 Academic Editor: Jennifer Elizabeth Jardine, University of Cambridge School of Clinical Medicine, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND Received: November 6, 2025; Accepted: June 17, 2026; Published: July 17, 2026 Copyright: © 2026 Björk et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability: The data underlying this study are not publicly available due to restrictions under the Swedish Public Access to Information and Secrecy Act and the General Data Protection Regulation (GDPR), as they contain sensitive personal information from national health registers. Researchers who meet the criteria for access to confidential data may apply for access to the data from Statistics Sweden (SCB) and the Swedish National Board of Health and Welfare (Socialstyrelsen). Information regarding data access from Statistics Sweden is available at: https://www.scb.se/en/services/ordering-data-and-statistics/ordering-microdata/ Information regarding data access from the Swedish National Board of Health and Welfare is available at: https://www.socialstyrelsen.se/en/statistics-and-data/register/ Questions regarding data access may be directed to mikrodata@socialstyrelsen.se. Funding: IB and GA were funded by Region Stockholm, Sweden (HMT and FoUI-1002823).https://www.regionstockholm.se/forskning-innovation/. ÄM was funded by Region Stockholm (clinical research appointment) https://www.regionstockholm.se/forskning-innovation/ and The Strategic Research Area in Epidemiology and Biostatistics (SFOEpi) https://ki.se/forskning/forskningsomraden-centrum-och-natverk/strategiska-forskningsomraden/strategiska-forskningsomradet-epidemiologi-och-biostatistik-sfoepi. The funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report. Competing interests: The authors have declared that no competing interests exist. Abbreviations: ADHD, attention deficit/hyperactivity disorder; aOR, adjusted odds ratio; ASD, autism spectrum disorder; ATC, Anatomical Therapeutic Chemical; BMI, body mass index; CI, confidence interval; CIF, cumulative incidence function; CP, cerebral palsy; ECD, emergency cesarean delivery; EP, epilepsy; HRs, hazard ratios; ID, intellectual disability; ORs, odds ratios; PIN, personal identification number; STROBE, Strengthening the Reporting of Observational Studies in epidemiology; VAD, vacuum-assisted delivery Introduction Ensuring a safe delivery is crucial for minimizing neonatal complications, reducing infant morbidity, and preventing long-term adverse health outcomes. The second stage of labor represents a particularly vulnerable period for the fetus, during which complications are most likely to arise [1,2]. Operative delivery, including vacuum-assisted delivery (VAD), may be required in cases of fetal distress or dystocia. In Sweden, VAD accounts for 6%–9% of all deliveries, whereas forceps are rarely used [3]. VAD performed with the fetal head at outlet station is typically a brief procedure with minimal risk of injury in term-born infants and represents approximately half of all VADs [4]. However, several studies indicate a risk of severe neonatal complications, including intracranial hemorrhage, seizures and death, associated with VAD performed at mid/low station [5–10]. These differences may reflect a more complex procedure, for example shown as higher traction forces in mid/low VAD than at the outlet station [11,12]. Despite observations of unfavorable neonatal outcomes in mid/low VAD, research on long-term neurodevelopmental outcomes remains limited and largely based on outdated cohorts [13–15]. Some recent studies report no significant associations between VAD and adverse long-term neurodevelopmental outcomes, although most have not distinguished between outlet and mid/low station procedures [16–19]. Consequently, important knowledge gaps remain regarding the long-term safety of VAD, particularly according to fetal head station. From a global maternal health perspective, maintaining access to safe instrumental vaginal delivery remains important, particularly in settings with limited surgical capacity and high maternal morbidity [20]. Clarifying the long-term safety of VAD is therefore essential to support safe obstetric practice and sustain competence in instrumental vaginal delivery worldwide. Given these knowledge gaps, this study aimed to investigate neonatal and long-term neurodevelopmental outcomes after VAD, stratified by fetal station, in a nationwide population-based cohort. Emergency cesarean delivery (ECD) and spontaneous vaginal delivery were included as reference groups to contextualize outcomes after VAD. Methods Study design, setting and data sources This nationwide cohort study was conducted in Sweden, where the personal identification number (PIN) assigned to each resident enables complete linkage across population-based health and demographic registers [21]. The country’s tax-funded healthcare system ensures universal access to standardized, high-quality maternal and neonatal care, with nearly all deliveries occurring in hospital settings. These features provide an ideal infrastructure for unbiased, long-term follow-up in perinatal epidemiology [22]. The study base was identified through the Swedish Medical Birth Register, which has prospectively collected data on pregnancies, deliveries, and neonatal outcomes since 1973, covering more than 98% of all births in Sweden. The register has been validated and demonstrates high completeness and accuracy for key perinatal variables [23]. Using the PIN, we linked data from the Medical Birth Register with several nationwide health and demographic registers to define exposures, outcomes, and covariates of interest. These included the National Patient Register, which contains International Classification of Diseases (ICD)-coded diagnoses from inpatient (full coverage since 1987) and specialized outpatient (since 2001) care; the Prescribed Drug Register, capturing all dispensed prescriptions since 2005 [24]; the Cause of Death Register, recording dates underlying causes of death [25]; the Total Population Register, providing demographic information [22]; the Longitudinal Integration Database for Health Insurance and Labor Market Studies (LISA), which includes socioeconomic information, such as income and educational level of all residents [26]. These registers have been extensively validated, and are characterized by near-complete national coverage and high diagnostic accuracy, providing a uniquely robust platform for population-based research using real-world data. Study participants The study base included all singleton term births (≥37 + 0 gestational weeks) to primiparous women registered in the Medical Birth Register between 1997 and 2014. The study period ensured that all children reached at least 7 years of age, allowing sufficient time for reliable ascertainment of outcomes. Children born preterm, in breech presentation, delivered by forceps, or with congenital malformations were excluded. Exposure The exposed cohort comprised children born via VAD, further classified as outlet VAD or mid/low VAD according to surgical procedure code in the birth register (see Table A in S1 Appendix). In the Swedish classification, VAD is defined by fetal head station: above the ischial spine as high station, from the ischial spine to just above the pelvic floor as mid/low, and at the pelvic floor as outlet. This differs slightly from international classification, where mid and low stations are reported as separate categories. Comparison cohorts Children born via VAD were compared with two reference groups: (i) those delivered by ECD, and (ii) those delivered by spontaneous vaginal delivery. Mode of delivery was identified through standardized registration in the birth register. This dual-comparator design enabled evaluation of VAD outcomes in relation to both surgical intervention and unassisted vaginal birth. Outcomes and follow-up Neonatal outcomes. Severe neonatal outcomes were identified using ICD-10 diagnosis codes recorded in the Medical Birth Register or the National Patient Register. Outcomes included asphyxia, intracerebral hemorrhage (traumatic and non-traumatic), cephalohematoma, subgaleal hematoma, meconium aspiration, respiratory distress, neonatal seizures, and ischemic stroke. These diagnoses represent clinically significant neonatal complications with potential implications for both acute and long-term morbidity. Please refer to Table A in S1 Appendix for the ICD codes used. Long-term neurodevelopmental outcomes All children were followed for the occurrence of attention deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), cerebral palsy (CP), epilepsy (EP), and intellectual disability (ID). Each outcome was defined as the presence of at least two registered diagnoses in the National Patient Register. For ADHD, dispensed prescriptions were also considered: ADHD was defined as either (i) two registered diagnoses or (ii) one registered diagnosis in combination with a dispensed prescription for ADHD medication. For ICD codes and Anatomical Therapeutic Chemical (ATC) classifications, see Table A in S1 Appendix. Follow-up began at disorder-specific ages to avoid misclassification from early or unreliable diagnoses: from 3 months of age for CP, EP, and ID; from 1 year for ASD; and from 3 years for ADHD. For EP, this approach ensured the exclusion of neonatal seizures. The follow-up period extended from the start of follow-up until the respective endpoint, death, migration, or 31 December 2021, whichever occurred first. Overall follow-up ranged from 7 to 24 years. Statistical analysis This study is reported as per the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guideline (S1 Checklist). The study design and statistical analyses were specified prospectively in an analysis plan developed before data analysis (S1 Protocol). Additional analyses and reporting modifications introduced during manuscript development and peer review, including comparison of births with known and unspecified fetal head station, cumulative incidence functions, assessment of the proportional hazards assumption, and presentation of absolute risks, were undertaken to assess the robustness and interpretation of the findings. Baseline characteristics were summarized as means (SD) for continuous variables and proportions for categorical variables. Logistic regression models were used to estimate odds ratios (ORs) with 95% confidence intervals (CIs) for associations between mode of delivery and adverse neonatal outcomes. For long-term neurodevelopmental outcomes, incidence rates were calculated per 1,000 person-years, and Cox proportional hazards regression models were applied to estimate hazard ratios (HRs) with 95% CIs. Cumulative incidence functions (CIFs) were estimated to illustrate how risk accumulated over time while accounting for competing events and are presented in Fig A in the S1 Appendix. Visual inspection of the CIFs showed broadly parallel trajectories, with only small absolute differences in risk over time. The proportional hazards assumption was evaluated by including time-dependent interaction terms between the exposure and log(follow-up time). These tests provided no evidence of departures from proportionality (p-values [0.06, 0.95]) (Table B in the S1 Appendix). For neonatal outcomes, multivariable models were adjusted for maternal age, body mass index (BMI), gestational age, preeclampsia, gestational diabetes, and diabetes mellitus type I/II. All multivariable models for long-term outcomes were adjusted for pre-specified covariates identified a priori from established literature. Confounder adjustment was performed sequentially in three steps. Model 1 included maternal age, smoking status, BMI, diabetes mellitus type I/II, and child’s birth year. Model 2 additionally included preeclampsia, gestational diabetes, and chorioamnionitis. Model 3 further included maternal education level and maternal psychiatric comorbidity (ADHD, ASD, depression, and anxiety). Analyses were conducted in the overall cohort and stratified by child sex. All analyses were performed using complete case methodology; individuals with missing information on any covariate included in the multivariable models were excluded from the respective analyses. Several pre-defined sensitivity analyses were undertaken to assess the robustness of findings: (i) exclusion of children diagnosed with perinatal asphyxia (definition in Table A in the S1 Appendix); (ii) stratification by gestational age (early term [37 + 0–38 + 6], full term [39 + 0–40 + 6], late term [41 + 0–41 + 6], and post-term [≥42 + 0]); (iii) stratification by birth period (1997–2006 and ≥2007); and (iv) stratification by birthweight category (small, appropriate, and large for gestational age). All analyses were performed using SAS statistical software, version 9.4 (SAS Institute, Cary, NC, USA). Patient and public involvement Patients and/or the public were not involved in the design, conduct, reporting, or dissemination plans of this research. Ethics Ethical approval for the study was obtained from the Swedish Ethical Review Authority (Ref. no. 2022-02513-01). The requirement for informed consent was waived by the Swedish Ethical Review Authorit
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