Race-Specific Association of Caesarean-Section Delivery with Body Size at Age 2 Years
Authors: Cassidy-Bushrow Andrea E , Wegienka Ganesa , Havstad Suzanne , Levin Albert M. , Lynch Susan V. , Ownby Dennis R. , Rundle Andrew G. , Woodcroft Kimberley J. , Zoratti Edward M. , Cole Johnson Christine 
Published: January 2016

<p><span style="font-family: Times New Roman;"><strong><span style="font-size: medium;">Objectives:</span></strong><span style="font-size: medium;"> African American children are at higher risk of obesity than White children and African American women are more likely to undergo caesarean-section (CS) delivery than White women.</span><span style="font-size: medium;"> </span><span style="font-size: medium;">CS is associated with childhood obesity, however, little is known whether this relationship varies by race.</span><span style="font-size: medium;">We examined if the association of CS with obesity at age 2 years varied by race.</span><span style="font-size: medium;"> </span></span></p><p><span style="font-family: Times New Roman;"><strong><span style="font-size: medium;">Design: </span></strong><span style="font-size: medium;">Longitudinal birth cohort.</span><strong></strong></span></p><p><span style="font-family: Times New Roman;"><strong><span style="font-size: medium;">Setting:</span></strong><span style="font-size: medium;"> Birth cohort conducted in a health care system in metropolitan Detroit, Michigan with follow-up at age 2 years.</span></span></p><p><span style="font-family: Times New Roman;"><strong><span style="font-size: medium;">Participants:</span></strong><span style="font-size: medium;"> 639 birth cohort participants; 367 children (57.4%) were born to African American mothers and 230 (36.0%) children were born via CS.</span></span></p><p><span style="font-family: Times New Roman;"><strong><span style="font-size: medium;">Main Outcome Measure: </span></strong><span style="font-size: medium;">Obesity defined as body mass index </span><strong></strong><span style="font-size: medium;">≥95</span><sup><span style="font-size: small;">th</span></sup><span style="font-size: medium;"> percentile at age 2 years.</span></span></p><p><span style="font-family: Times New Roman;"><strong><span style="font-size: medium;">Results:</span></strong><span style="font-size: medium;"> Slightly more children of African American (n=37; 10.1%) than non-African American mothers (n=18; 6.6%) were obese (</span><span style="font-size: medium;">P</span><span style="font-size: medium;">=.12). There was evidence of effect modification between race and delivery mode with obesity at age 2 years (interaction<em> </em></span><span style="font-size: medium;">P</span><span style="font-size: medium;">=.020).</span><span style="font-size: medium;"> </span><span style="font-size: medium;">In children of African-American mothers, CS compared to vaginal birth was associated with a significantly higher odds of obesity (aOR=2.35 (95% CI: 1.16, 4.77), </span><em><span style="font-size: medium;">P</span></em><span style="font-size: medium;">=.017).</span><span style="font-size: medium;"> </span><span style="font-size: medium;">In contrast, delivery mode was not associated with obesity at age 2 years in children of non-African-American mothers (aOR=.47 (95% CI: .13, 1.71), </span><span style="font-size: medium;">P</span><span style="font-size: medium;">=.25).</span><span style="font-size: medium;"> </span></span></p><p><span style="font-family: Times New Roman;"><strong><span style="font-size: medium;">Conclusions:</span></strong><span style="font-size: medium;"> There is evidence for a race-specific effect of CS on obesity at age 2 years; potential underlying mechanisms may be racial differences in the developing gut microbiome or in epigenetic programming.</span><span style="font-size: medium;"> </span><span style="font-size: medium;">Future research is needed to determine if this racial difference persists into later childhood. <em>Ethn Dis.</em> 2016;26(1):61-68; doi:10.18865/ed.26.1.61<br /></span></span></p><p> </p>