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Mode of birth may affect infant BMI at age 1 and 3 years

Mar 24, 2018

Infants born to mothers with overweight or obesity were more likely to have overweight or obesity at age 1 and 3 years compared with those born to mothers with normal weight, and those delivered by cesarean section to mothers with elevated BMI were the most likely to have overweight or obesity, according to findings published in JAMA Pediatrics. 


Anita L. Kozyrskyj, PhD, professor in the department of pediatrics at the University of Alberta in Canada, and colleagues evaluated data from the Canadian Healthy Infant Longitudinal Development (CHILD) birth cohort on 935 mothers (mean age, 32.5 years; 50.9% overweight [BMI 25 kg/m2]) and their infants born between 2009 and 2012 to determine the association between mode of delivery with microbiota in the infant gut and whether that mode mediates the association between maternal and child overweight. The main outcome was risk for overweight and obesity ( 97th percentile BMI z scores) among children at age 1 and 3 years. 

Overall, 7.5% of infants had overweight or obesity at age 1 year, and 10.4% at age 3 years. 

The odds for cesarean section were 1.5 times greater among women with overweight or obesity compared with those with normal weight. 

Compared with infants born to mothers with normal weight, those born to mothers with overweight or obesity were more likely to have overweight or obesity at age 1 year (adjusted OR = 3.8; 95% CI, 1.88-7.66) and 3 years (aOR = 3.79; 95% CI, 2.1-6.84). Compared with infants delivered vaginally without intrapartum antibiotic prophylaxis, those delivered by emergency cesarean section had double the odds for childhood overweight or obesity at age 1 and 3 years.

Among infants delivered vaginally without intrapartum antibiotic prophylaxis, those with mothers with overweight or obesity had three times greater odds of having elevated BMI at age 1 (OR = 3.33; 95% CI, 1.49-7.41) and 3 years (OR = 3.07; 95% CI, 1.58-5.96) compared with normal-weight mothers. The odds for overweight or obesity were five times greater among scheduled cesarean deliveries of mothers with overweight or obesity compared with infants delivered vaginally to normal-weight mothers without intrapartum antibiotic prophylaxis at age 1 year (OR = 5.02; 95% CI, 2.04-12.38) and 3 years (OR = 5.55; 95% CI, 2.55-12.04). 

The association between maternal prepregnancy overweight and childhood overweight at age 1 and 3 years was mediated by birth mode and infant gut microbiota. Mothers with overweight were more likely to have an abundance of the bacterial genera belonging to the Lachnospiraceaefamily compared with mothers with normal weight; however, Lachnospiraceaeabundance also varied among infants delivered vaginally and by cesarean section. 

In an accompanying editorial, Giulia Paolella, MD, from the Pediatric Intermediate Care Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, and Pietro Vajro, MD, from the department of medicine, surgery and dentistry at the University of Salerno, Italy, wrote that the large participant population was a strength of the study. 

"They found that richness in Firmicutes species and increased abundance of Lachnospiraceaewere important for the intergenerational transmission of [overweight or obesity]," they wrote. "Future studies are needed to confirm these results and to understand more deeply the multiple factors implicated in a hitherto still complex interplay. Further clarification of the mechanisms leading to the development of childhood obesity may pave the way to novel strategies for obesity prevention that include the interruption of intergenerational transmission of [overweight or obesity] from mother to offspring."

Tun HM, Bridgman SL, Chari R, Field CJ, Guttman DS, Becker AB, Mandhane PJ, Turvey SE, Subbarao P, Sears MR, Scott JA, Kozyrskyj AL, . Roles of Birth Mode and Infant Gut Microbiota in Intergenerational Transmission of Overweight and Obesity From Mother to Offspring. JAMA Pediatr. Published online February 19, 2018

Links : https://www.healio.com/endocrinology/obesity/news/in-the-journals/%7B8df4eada-c682-4a22-a7ae-238ef13422d0%7D/mode-of-birth-may-affect-infant-bmi-at-age-1-and-3-years