# Long-Term Neurodevelopmental Outcomes After Forceps, Vacuum, and Second-Stage Cesarean Delivery

## TL;DR

A study of over 500,000 children found that certain delivery methods in the second stage of labor are linked to higher risks of ADHD and intellectual disability.

## Contribution

The study compares neurodevelopmental outcomes of specific delivery methods that are typically not directly compared in prior research.

## Key findings

- Children delivered via sequential instrument delivery had a 13% higher ADHD rate compared to second-stage cesarean delivery.
- Vacuum delivery was associated with a 53% higher rate of intellectual disability compared to second-stage cesarean delivery.
- Autism spectrum disorder rates were not significantly associated with any mode of delivery.

## Abstract

Is there an association between mode of delivery in the second stage of labor and attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and intellectual disability (ID)?

This cohort study of 504 380 children found higher rates of ADHD among children who underwent sequential instrument delivery compared with second-stage cesarean delivery, higher rates of ID among those who underwent vacuum delivery, and similar rates of ASD between mode of delivery groups.

The findings of this study suggest that operative vaginal delivery and second-stage cesarean delivery have comparable neurodevelopmental outcomes among offspring, except among those who underwent sequential instrument and vacuum delivery, which were associated with ADHD and ID, respectively.

Prior studies have compared neurodevelopmental outcomes across delivery modes that are not interchangeable (eg, operative vs spontaneous vaginal delivery [SVD]), limiting the clinical utility of their conclusions.

To examine the association between mode of operative delivery in the second stage of labor and attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and intellectual disability (ID) in children.

This population-based, retrospective cohort study used data from health administrative databases from British Columbia, Canada, from April 1, 2000, to December 31, 2019. The population included 504 380 nonanomalous, singleton, full-term infants who survived and did not emigrate during their first year of life. Neurodevelopmental outcomes were collected through March 31, 2022, and analyses were performed from June 2024 to August 2025.

Delivery mode during the second stage of labor, categorized as SVD, forceps, vacuum, sequential instrument, or second-stage cesarean delivery (SSCD).

The main outcome was ADHD, ASD, and ID from 1 year to a maximum of 22 years of age. Cox proportional hazards regression models were used to assess the association between mode of operative delivery (SVDs excluded) and each neurodevelopmental outcome, adjusting for maternal and clinical characteristics.

Among 504 380 children (253 256 males [50.2%] and 44 202 [8.8%] with a maternal history of neurodevelopmental or psychiatric disorders), 407 792 (80.9%) were delivered by SVD, 46 493 (9.2%) by vacuum, 23 140 (4.6%) by forceps, 3009 (0.6%) by sequential instrument, and 23 946 (4.7%) by SSCD. The overall rate of ADHD was 6.6 (95% CI, 6.5-6.7) per 1000 person-years; ASD, 1.8 (95% CI, 1.7-1.8) per 1000 person-years; and ID, 0.3 (95% CI, 0.2-0.3) per 1000 person-years. Compared with SSCD, children who underwent sequential instrument delivery had a 13% higher ADHD rate (7.9 [95% CI, 7.1-8.8] vs 6.6 [95% CI, 6.3-6.9] per 1000 person-years; adjusted hazard ratio [AHR], 1.13 [95% CI, 1.00-1.28]) and those who underwent vacuum delivery had a 53% higher ID rate (0.3 [95% CI, 0.3-0.4] vs 0.2 [95% CI, 0.1-0.3] per 1000 person-years; AHR, 1.53 [95% CI, 1.12-2.10]). There was no significant association with ASD and mode of delivery.

The findings of this cohort study suggest that children who underwent operative vaginal delivery and SSCD had comparable neurodevelopmental outcomes, except among those who underwent sequential instrument delivery and vacuum delivery, which were associated with ADHD and ID, respectively. Further research is warranted to develop a better understanding of delivery mode as a potentially modifiable risk factor for neurodevelopmental disorders in childhood.

This cohort study examines the association between mode of operative delivery in the second stage of labor and attention-deficit/hyperactivity disorder, autism spectrum disorder, and intellectual disability among children born in British Columbia, Canada.