Babies delivered with forceps are more likely to develop problems with aggression during childhood compared with those born by Caesarean section, according to a study in China.
Researchers believe the behavioral problems may be linked to high levels of cortisol, a hormone the body produces during a difficult birth.
Previous studies have found that cortisol levels in cord blood are lowest in babies born by elective Caesarean, and next lowest in babies born via spontaneous vaginal delivery.
The highest levels of cortisol are found in those born by assisted vaginal delivery using forceps or vacuum extraction.
“Cortisol levels have been linked to childhood psychopathology, however, more studies are still needed to look at this in more detail,” write Dr. Jianmeng Liu, of Peking University Health Science Center in Beijing, and colleagues. Their paper was published online today in the obstetrics journal BJOG.
The study involved 4,190 children who were born in China’s southern provinces of Zhejiang and Jiangsu. The children were assessed between the ages of 4 and 6 for problems such as being withdrawn, anxious, depressed, having attention difficulties, and delinquent and aggressive behavior.
Such problems were lowest in children delivered by caesarean section and highest in those delivered using instruments, the researchers said.
Caesarean births are increasing in China, particularly in the richer southeastern parts of the country where rates have risen to 56% in 2006 from 22% in 1994.
Caesarean delivery on request by mothers is a major contributor to this trend. It accounted for 3.6% of all caesarean births in 1994 and 36% in 2006 in southeast China.0