Vacuum and forceps use for delivery were associated with higher risk of developing attention-deficit/hyperactivity disorder (ADHD) and intellectual disability, compared with second-stage cesarean delivery, according to a study published in JAMA Network Open.

The findings address a common clinical question of whether late-stage delivery choices meaningfully change a child’s long-term risk for neurodevelopmental disorders. However, experts say the results are unlikely to shift real-time decision-making in the delivery room. 

“Immediate maternal and neonatal risks take priority over long-term associations when a patient is in labor," said Andrea Edlow, MD, a maternal-fetal specialist at Massachusetts General Hospital in Boston, who was not involved in the study. 

“Typically, patient, fetus, and clinical factors are the biggest considerations in deciding between operative delivery and second-stage cesarean,” which can include fetal size and position and maternal pushing efforts, Edlow said. 

Canadian researchers analyzed data of more than 500,000 full-term births in British Columbia that occurred between 2000 and 2019, with a follow-up of up to 22 years. Most births occurred by spontaneous vaginal delivery (80.9%), with much smaller proportions delivered by vacuum (9.2%), forceps (4.6%), second-stage cesarean (4.7%), and sequential instruments (0.6%). 

After adjusting for maternal, obstetric, and infant factors, children delivered with sequential instruments (vacuum followed by forceps) had a slightly higher risk for ADHD than those delivered by second-stage cesarean (adjusted hazard ratio [aHR], 1.13; 95% CI, 1.00-1.28; P = .03). Children delivered by vacuum had a 53% higher risk for intellectual disability than those delivered by second-stage cesarean (aHR, 1.53; 95% CI, 1.12–2.10; P = .01). Forceps delivery alone was not associated with a statistically significant increase in these outcomes. Rates of autism spectrum disorder also did not differ significantly by delivery mode. 

However, absolute differences were small. ADHD occurred at a rate of 7.9 per 1000 person-years among children born via sequential instrument delivery, compared with 6.6 per 1000 person-years for second-stage cesarean delivery. Intellectual disability occurred at a rate of 0.3 per 1000 person-years after vacuum delivery vs 0.2 per 1000 person-years after second-stage cesarean delivery. 

Edlow said that most obstetricians choose vacuum or forceps on the basis of their training and comfort. As the study showed, both are much rarer in the United States and not considered standard care. Edlow said operative vaginal delivery, by forceps or vacuum during the second stage of labor, can also sometimes be faster than moving to cesarean. 

“It is well known that obstetricians should avoid sequential operative delivery, and this is not standard practice in the US,” she said. 

Since the early 2000s, the American College of Obstetricians and Gynecologists has advised against operative vaginal deliveries due to concerns about a higher risk for intracranial hemorrhage, occurring in roughly 1 in 650-850 of these births, and severe neurologic complications, occurring in about 1 in 220-385 infants delivered with forceps or vacuum. 

But some injuries attributed to operative vaginal delivery may relate to the underlying reason for the intervention, such as fetal distress, and cesarean delivery does not necessarily reduce risk for those injuries. 

Edlow said obstetricians should focus first on preventing immediate harm to the newborn, because most long-term risks are probably related to complications during birth vs the delivery method itself. 

If no serious birth complications occur, “it’s hard to understand how operative delivery would impact later child neurodevelopment,” she said. 

One of the study authors reported receiving grants from the Swedish Research Council during the conduct of the study. No other disclosures were reported.

Edlow declared no conflicts of interest. 

Lara Salahi is a health journalist based in Boston.