Objective Gestational weight gain (GWG) is positively associated with birth weight and maternal pre-pregnancy BMI is directly related to infant fat mass (FM). This study examined whether differences exist in infant body composition based on 2009 GWG recommendations. Study Design Body composition was measured in 306 infants and GWG was categorized as appropriate or excessive. Analysis of covariance was used to investigate the effects of GWG and pre-pregnancy BMI and their interaction on infant body composition. Results Within the appropriate group, infants from obese mothers had greater percent fat (%fat) and FM than offspring from normal and overweight mothers. Within the excessive group, infants from normal mothers had less %fat and FM than infants from overweight and obese mothers. A difference was found for %fat and FM within the overweight group between GWG categories. Conclusions Excessive GWG is associated with greater infant body fat and the effect is greatest in overweight women.

Background Ethnic differences in total body fat (fat mass [FM]) have been reported in adults and children, but the timing of when these differences manifest and whether they are present at birth are unknown. Objectives This study aimed to assess whether ethnic differences in body fat are present at birth in healthy infants born at term, where body fat is measured using air displacement plethysmography and fat distribution by skin-fold thickness. Methods Data were from a multiracial cross-sectional convenience sample of 332 term infants from four racial or ethnic groups based on maternal self-report (A, Asian; AA, non-Hispanic Black [African-American]; C, non-Hispanic White; and H, Hispanic). The main outcome measure was infant body fat at 1–3 days after birth, with age, birth weight, gestational age and maternal pre-pregnancy weight as covariates. Results Significant effects for race (P = 0.0011), sex (P = 0.0051) and a race by sex interaction (P = 0.0236) were found. C females had higher FM than C males (P = 0.0001), and AA females had higher FM than AA males (P = 0.0205). C males had less FM than A males (P = 0.0353) and H males (P = 0.0001). Conclusion Race/ethnic and sex differences in FM are present in healthy term newborns. Although the implications of these differences are unclear, studies beginning in utero and birth set the stage for a life course approach to understanding disease later in life.

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disease primarily affecting the optic nerves and spinal cord, which is usually associated with anti-aquaporin-4 antibodies. Here, we present two individuals who were negative for anti-aquaporin-4 antibodies and were initially diagnosed with seronegative NMOSD. Each patient’s clinical course and radiographic features raised suspicion for an alternative disease process. Both individuals were found to have pathogenic variants of MT-ND5, encoding subunit 5 of mitochondrial complex I, ultimately leading to a revised diagnosis of a primary mitochondrial disorder. These cases illustrate the importance of biochemical and genetic testing in atypical cases of NMOSD.

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