Human Milk Oligosaccharides, Growth, and Body Composition in Very Preterm Infants

Human milk oligosaccharides (HMOs) are bioactive factors that benefit neonatal health, but little is known about effects on growth in very preterm infants (<32 weeks' gestation). We aimed to quantify HMO concentrations in human milk fed to very preterm infants during the neonatal hospitalization and investigate associations of HMOs with infant size and body composition at term-equivalent age. In 82 human-milk-fed very preterm infants, we measured HMO concentrations at two time points. We measured anthropometrics and body composition with air displacement plethysmography at term-equivalent age. We calculated means of individual and total HMOs, constructed tertiles of mean HMO concentrations, and assessed differences in outcomes comparing infants in the highest and intermediate tertiles with the lowest tertile using linear mixed effects models, adjusted for potential confounders. The mean (SD) infant gestational age was 28.2 (2.2) weeks, and birthweight was 1063 (386) grams. Exposure to the highest (vs. lowest) tertile of HMO concentrations was not associated with anthropometric or body composition z-scores at term-corrected age. Exposure to the intermediate (vs. lowest) tertile of 3FL was associated with a greater head circumference z-score (0.61, 95% CI 0.15, 1.07). Overall, the results do not support that higher HMO intakes influence growth outcomes in this very preterm cohort.

Lactoferrin intake from maternal milk during the neonatal hospitalization and early brain development among preterm infants

BACKGROUND

Lactoferrin is an immuno-modulatory nutrient in human milk that may be neuroprotective.

METHODS

In 36 infants born <32 weeks' gestation, we sampled human milk at 14 and 28 days of chronologic age and measured lactoferrin by electrochemiluminescence multiplex immunoassay. Using 3T quantitative brain magnetic resonance imaging scans obtained at term equivalent, we estimated total and regional brain volumes. We compared outcomes between infants exposed to low (bottom tertile, range 0.06-0.13 mg/mL) vs. high (top tertile, range 0.22-0.35 mg/mL) lactoferrin using median regression in models adjusted for gestational age, birth weight z-score, sex, and postmenstrual age.

RESULTS

Compared to infants exposed to low lactoferrin, infants exposed to high lactoferrin had 43.9 cc (95% CI: 7.6, 80.4) larger total brain volume, 48.3 cc (95% CI: 12.1, 84.6) larger cortical gray matter, and 3.8 cc (95% CI: 0.7, 7.0) larger deep gray matter volume at term equivalent age. Other regional brain volumes were not statistically different between groups.

CONCLUSION

Higher lactoferrin exposure during the neonatal hospitalization was associated with larger total brain and gray matter volumes, suggesting that lactoferrin may have potential as a dietary supplement to enhance brain growth in the neonatal intensive care unit setting.

IMPACT

This study suggests that lactoferrin, a whey protein found in human milk, may be beneficial for preterm infant brain development, and therefore has potential as a dietary supplement in the neonatal intensive care unit setting.

Growth Velocities Across Distinct Early Life Windows and Child Cognition: Insights from a Contemporary US Cohort

OBJECTIVE

To evaluate the relative importance of overall and period-specific postnatal growth and their interaction with fetal growth on cognition in a generally well-nourished population.

STUDY DESIGN

We included 1052 children from Project Viva, a prospective cohort in Boston, Massachusetts. Using linear spline mixed-effects models, we modeled length/height and body mass index (BMI) trajectories from birth to 7 years and estimated standardized overall (0-7 years) and period-specific growth velocities ie, early infancy (0-4 months), late infancy (4-15 months), toddlerhood (15-37 months), and early childhood (37-84 months). We investigated associations of growth velocities as well as their interactions with birthweight-for-gestational age on mid-childhood (mean age: 7.9 years) IQ, visual memory and learning, and visual motor ability.

RESULTS

Greater overall height velocity was associated with modestly higher design memory score, (adjusted β [95% CI] 0.19 [-0.01,0.38] P = .057])points per SD increase but lower verbal IQ (-0.88 [-1.76,0.00] P = .051). Greater early infancy height velocity was associated with higher visual motor score (1.92 [0.67,3.18]). Greater overall BMI velocity was associated with lower verbal IQ (-0.71 [-1.52,0.11] P = .090). Greater late infancy BMI velocity was associated with lower verbal IQ (-1.21 [-2.07,-0.34]), design memory score (-0.22 [-0.42,-0.03)], but higher picture memory score (0.22 [0.01,0.43]). Greater early infancy height velocity (-1.5 SD vs 1.5 SD) was associated with higher nonverbal IQ (margins [95% CI] 102.6 [98.9106.3] vs 108.2 [104.9111.6]) among small-for-gestational age infants (P-interaction = 0.04).

CONCLUSIONS

Among generally well-nourished children, there might not be clear cognitive gains with faster linear growth except for those with lower birthweight-for-gestational age, revealing the potential importance of early infancy compensatory growth.

Novel metrics to characterize temporal lobe of very preterm infants on term-equivalent brain MRI

BACKGROUND

Preterm birth adversely impacts brain development and contributes to neurodevelopmental impairment; the temporal lobe may be particularly vulnerable to the impact of very preterm (VP) birth. Yet, no prior magnetic resonance imaging (MRI) scoring system incorporated a method to quantify temporal lobe size in VP infants.

METHODS

We developed and applied three metrics (temporal lobe length, extra-axial space, and temporal horn width) to quantify temporal lobe structure on term-equivalent brain MRIs obtained from 74 VP and 16 term infants. We compared metrics between VP and term infants and explored associations of each metric with perinatal risk factors.

RESULTS

All metrics had excellent reliability (intra-class correlation coefficient 0.62-0.98). VP infants had lower mean temporal lobe length (76.8 mm versus 79.2 mm, p = 0.02); however, the difference attenuated after correction for postmenstrual age. VP infants had larger temporal horn widths compared with term infants (2.6 mm versus 1.8 mm, p < 0.001). Temporal lobe length was positively associated with gestational age, birth weight, and male sex, and negatively associated with the duration of parenteral nutrition.

CONCLUSIONS

The proposed metrics are reliable and sensitive in distinguishing differences in temporal lobe development between VP and full-term infants.

IMPACT

We developed a novel method for quantifying temporal lobe size among very preterm infants at term equivalent using simple metrics performed on brain MRI. Temporal lobe metrics were reliable, correlated with brain volume from volumetric analysis, and were sensitive in identifying differences in temporal lobe development among preterm compared with term infants, specifically larger temporal horn size in preterm infants. This temporal lobe metric system will enable future work to delineate the perinatal and postnatal factors that impact temporal lobe growth, and better understand the relationship between temporal lobe disturbance and neurodevelopment in very preterm infants.

Infant factors that impact the ecology of human milk secretion and composition-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 3

Infants drive many lactation processes and contribute to the changing composition of human milk through multiple mechanisms. This review addresses the major topics of milk removal; chemosensory ecology for the parent-infant dyad; the infant's inputs into the composition of the human milk microbiome; and the impact of disruptions in gestation on the ecology of fetal and infant phenotypes, milk composition, and lactation. Milk removal, which is essential for adequate infant intake and continued milk synthesis through multiple hormonal and autocrine/paracrine mechanisms, should be effective, efficient, and comfortable for both the lactating parent and the infant. All 3 components should be included in the evaluation of milk removal. Breastmilk "bridges" flavor experiences in utero with postweaning foods, and the flavors become familiar and preferred. Infants can detect flavor changes in human milk resulting from parental lifestyle choices, including recreational drug use, and early experiences with the sensory properties of these recreational drugs impact subsequent behavioral responses. Interactions between the infant's own developing microbiome, that of the milk, and the multiple environmental factors that are drivers-both modifiable and nonmodifiable-in the microbial ecology of human milk are explored. Disruptions in gestation, especially preterm birth and fetal growth restriction or excess, impact the milk composition and lactation processes such as the timing of secretory activation, adequacy of milk volume and milk removal, and duration of lactation. Research gaps are identified in each of these areas. To assure a sustained and robust breastfeeding ecology, these myriad infant inputs must be systematically considered.

Association of Primary Language with Provision of Mother's Milk Among Very-Low-Birthweight Infants in Massachusetts

Background: Racial/ethnic inequities in mother's milk provision for hospitalized preterm infants persist. The extent to which primary language contributes to these racial/ethnic inequities is unknown. Objective: Examine associations of maternal race/ethnicity and primary language with (1) any/exclusive mother's milk at hospital discharge and (2) the time to cessation of mother's milk provision during the hospitalization. Methods: We examined 652 mother/very-low-birthweight (VLBW) infant dyads at 9 level 3 neonatal intensive care units in Massachusetts from January 2017 to December 2018. We abstracted maternal race/ethnicity and language from medical records, and examined English and non-English-speaking non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic mothers of any race. We examined associations of race/ethnicity and language with (1) any/exclusive mother's milk at discharge (yes/no) using mixed-effects logistic regression and (2) cessation of mother's milk during the hospitalization using cox proportional hazard models, adjusting for gestational age, birthweight, and accounting for clustering by plurality and hospital. Results: Fifty-three percent were English-speaking NHW, 22% English-speaking NHB, 4% non-English-speaking NHB, 14% English-speaking Hispanic, and 7% non-English-speaking Hispanic. Compared with English-speaking NHW, NHB mothers (English adjusted odds ratio [aOR] 0.28 [0.17, 0.44]; and non-English-speaking aOR 0.55 [0.19, 0.98]), and non-English-speaking Hispanic mothers (aOR 0.29 [0.21, 0.87]) had lower odds of any mother's milk at discharge. In time-to-event analyses, non-English-speaking Hispanic (adjusted hazard ratio [aHR] 4.37 [2.20, 6.02]) and English-speaking NHB mothers (aHR 3.91 [1.41, 7.61] had the earliest cessation of mother's milk provision. Conclusion: In Massachusetts, maternal primary language was associated with inequities in mother's milk provision for VLBW infants with a differential effect for NHB and Hispanic mothers.

Human Milk Oligosaccharides and Infant Neurodevelopment: A Narrative Review

The objective of this narrative review was to synthesize the literature on human milk oligosaccharides (HMOs) and neurodevelopmental outcomes in human milk-fed infants. We conducted a scoping review of the literature indexed in PubMed reporting observational or interventional studies on HMO exposure in relation to psychometric measures in infants. Studies were characterized based on study design and definitions of HMO exposure and neurodevelopmental outcomes. Six studies were identified; all were observational in design, and five were conducted in full-term infants. Sample sizes ranged from 35-659 infants. HMOs were defined as individual concentrations or relative abundances assessed at 1 and/or 6 months of age. Studies accounted for differences in HMO exposure based on maternal secretor status. Neurodevelopmental outcomes were assessed between 6 and 24 months of age and included four domains. Studies in full-term infants reported that total and individual fucosylated and sialylated HMOs were positively associated with cognitive, language, and motor skill domains between 18 and 24 months of age, while the single study in preterm infants reported no statistically significant findings in the full cohort. The presence of a maternal secretor did not consistently alter the associations between HMO exposure and neurodevelopmental outcomes. Emerging evidence from observational studies suggests that HMO exposure may be beneficial for neurodevelopment in infants.

Associations of cord blood leukocyte telomere length with adiposity growth from infancy to adolescence

OBJECTIVE

Leukocyte telomere length (LTL) may be a biomarker for chronic disease susceptibility, but no work has tested this hypothesis directly. Our study investigated associations of LTL at birth with markers of adiposity growth that are linked with cardiometabolic health later in life.

METHODS

Participants were 375 children in Project Viva (48% female, 71% White). Body mass index (BMI) trajectories from birth to 18 years were tracked using repeated measures of BMI collected in physical examinations and via medical records, then used to predict age (months) and magnitude (kg/m2 ) of BMI peak and rebound. LTL was measured from cord blood via duplex quantitative PCR. A binary variable indicating LTL shorter than the reference population average was the primary exposure.

RESULTS

LTL was unrelated to BMI at peak or rebound, but associations were apparent with the timing of BMI growth milestones. Short LTL was related to a later age of peak for females (β = 0.99, 95% CI = 0.16, 1.82; psex interaction  = 0.015) and an earlier age of rebound for both males and females (βcombined  = -5.26, 95% CI = -9.44, -1.08).

CONCLUSION

LTL at birth may be an early biomarker of altered adiposity growth. Newborn telomere biology may shed new insight into the developmental origins of health and disease.

The Effects of COVID-19 Hospital Practices on Breastfeeding Initiation and Duration Postdischarge

Background: Early in the COVID-19 pandemic, many birth hospitals separated SARS-CoV-2-positive mothers from their newborn infants and advised against breastfeeding to decrease postnatal SARS-CoV-2 transmission. Information on how these practices impacted breastfeeding postdischarge is limited. Objectives: In a statewide sample of SARS-CoV-2-positive mothers, we aimed to determine the extent to which (1) mother-infant separation and (2) a lack of breastfeeding initiation in-hospital were associated with breast milk feeding postdischarge. Design/Methods: From 11 birthing hospitals in Massachusetts, we identified 187 women who tested positive for SARS-CoV-2 from 14 days before to 72 hours after delivery (March 1-July 31, 2020) and their newborn infants. We abstracted chart data from the delivery hospitalization on main exposure variables (mother-infant separation, in-hospital breast milk feeding [expressed milk feeding and/or direct breastfeeding]) and from outpatient visits until 30 days postdischarge. We evaluated associations of in-hospital practices with outcomes up to 30 days postdischarge, adjusting for confounders using multivariable logistic and linear regression. Results: Mother-infant separation in-hospital was associated with a shorter duration of any breast milk feeding (regression coefficient estimate -5.29 days, 95% confidence intervals [CI] [-8.89 to -1.69]). Direct breastfeeding in-hospital was associated with higher odds of any breast milk feeding (adjusted odds ratios [AOR] 5.68, 95% CI [1.65-23.63]) and direct breastfeeding (AOR 8.19, 95% CI [2.99-24.91]) postdischarge; results were similar for any breast milk feeding in-hospital. Conclusions: Perinatal hospital care practices implemented early in the COVID-19 pandemic, specifically mother-infant separation and prevention of breast milk feeding initiation, were associated with adverse effects on breast milk feeding outcomes assessed up to 1 month postdischarge.

Associations of body composition with regional brain volumes and white matter microstructure in very preterm infants

OBJECTIVE

To determine associations between body composition and concurrent measures of brain development including (1) Tissue-specific brain volumes and (2) White matter microstructure, among very preterm infants at term equivalent age.

DESIGN

Prospective observational study.

SETTING

Single-centre academic level III neonatal intensive care unit.

PATIENTS

We studied 85 infants born <33 weeks' gestation.

METHODS

At term equivalent age, infants underwent air displacement plethysmography to determine body composition, and brain MRI from which we quantified tissue-specific brain volumes and fractional anisotropy (FA) of white matter tracts. We estimated associations of fat and lean mass Z-scores with each brain outcome, using linear mixed models adjusted for intrafamilial correlation among twins and potential confounding variables.

RESULTS

Median gestational age was 29 weeks (range 23.4-32.9). One unit greater lean mass Z-score was associated with larger total brain volume (10.5 cc, 95% CI 3.8 to 17.2); larger volumes of the cerebellum (1.2 cc, 95% CI 0.5 to 1.9) and white matter (4.5 cc, 95% CI 0.7 to 8.3); and greater FA in the left cingulum (0.3%, 95% CI 0.1% to 0.6%), right uncinate fasciculus (0.2%, 95% CI 0.0% to 0.5%), and right posterior limb of the internal capsule (0.3%, 95% CI 0.03% to 0.6%). Fat Z-scores were not associated with any outcome.

CONCLUSIONS

Lean mass-but not fat-at term was associated with larger brain volume and white matter microstructure differences that suggest improved maturation. Lean mass accrual may index brain growth and development.

Associations of Maternal Milk Feeding With Neurodevelopmental Outcomes at 7 Years of Age in Former Preterm Infants

IMPORTANCE

Maternal milk feeding may have unique long-term neurodevelopmental benefits in very preterm infants.

OBJECTIVE

To examine the extent to which maternal milk feeding after very preterm birth is associated with cognitive, academic, and behavioral outcomes at school age.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study assessed 586 infants born at less than 33 weeks' gestation at 5 Australian perinatal centers and enrolled in the Docosahexaenoic Acid for Improvement of Neurodevelopmental Outcomes study (January 1, 2001, to December 31, 2005) who were evaluated at a corrected age of 7 years. The statistical analysis was completed on January 19, 2022.

EXPOSURES

Maternal milk intake, including mean volume (milliliters per kilogram per day) during neonatal hospitalization and total duration (in months).

MAIN OUTCOMES AND MEASURES

Neurodevelopmental outcomes at 7 years of age were (1) IQ (Wechsler Abbreviated Scale of Intelligence), (2) academic achievement (Wide Range Achievement Test, Fourth Edition), (3) symptoms of attention-deficit/hyperactivity disorder (ADHD) (Conners Third Edition ADHD Index, parent reported), (4) executive function (Behavior Rating Inventory of Executive Functioning, parent reported), and (5) behavior (Strengths and Difficulties Questionnaire, parent reported).

RESULTS

A total of 586 infants (mean [SD] gestational age at birth, 29.6 [2.3] weeks; 314 male [53.6%]) born to 486 mothers (mean [SD] age, 30.6 [5.5] years; 447 [92.0%] White) were included. Mean (SD) maternal milk intake in the neonatal intensive care unit was 99 (48) mL/kg daily, and mean (SD) maternal milk duration was 5.1 (5.4) months. Mean (SD) full-scale IQ was 98.5 (13.3) points. After covariate adjustment, higher maternal milk intake during the neonatal hospitalization was associated with higher performance IQ (0.67 points per additional 25 mL/kg daily; 95% CI, 0.10-1.23 points), reading scores (1.14 points per 25 mL/kg daily; 95% CI, 0.39-1.89 points), and math scores (0.76 points per 25 mL/kg daily; 95% CI, 0.14-1.37 points) and fewer ADHD symptoms (-1.08 points per 25 mL/kg daily; 95% CI, -1.96 to -0.20 points). Longer duration of maternal milk intake was associated with higher reading (0.33 points per additional month; 95% CI, 0.03-0.63 points), spelling (0.31 points per month; 95% CI, 0.01-0.62 points), and math (0.30 points per month; 95% CI, 0.03-0.58 points) scores. Maternal milk was not associated with improved full-scale IQ, verbal IQ, executive function, or behavior. Most associations were stronger among infants born at lower gestational ages, particularly less than 30 weeks (interaction P values <.01).

CONCLUSIONS AND RELEVANCE

In this cohort study of preterm infants, maternal milk feeding during the neonatal hospitalization and after discharge were associated with better school-age performance IQ and academic achievement and with a reduction in ADHD symptoms, particularly among infants born at less than 30 weeks' gestation.

The financial burden experienced by families of preterm infants after NICU discharge

BACKGROUND AND OBJECTIVES

Describe the financial burden and worry that families of preterm infants experience after discharge from the neonatal intensive care unit (NICU).

METHODS

We surveyed 365 parents of preterm infants in a cross-sectional study regarding socio-demographics, supplemental security income (SSI), and financial worry. We completed a multivariable logistic regression model to examine the adjusted association of financial worry with modifiable factors.

RESULTS

We found that 53% of participants worried about healthcare costs after NICU discharge. After adjusting for socio-demographic and infant characteristics, we identified that, aOR (95% CI), out-of-pocket costs from the NICU index hospitalization, 3.51 (1.7, 7.26) and durable medical equipment use, 2.41 (1.11, 5.23) was associated with increased financial worry while enrollment in SSI, 0.38 (0.19, 0.76) was associated with decreased financial worry.

CONCLUSIONS

We identified factors that could contribute to financial burden after NICU discharge that may advise future work to target financial support systems.

Systemic Inflammation in the First 2 Weeks after Birth as a Determinant of Physical Growth Outcomes in Hospitalized Infants with Extremely Low Gestational Age

OBJECTIVE

To examine associations of systemic inflammation with growth outcomes at neonatal intensive care unit discharge or transfer among infants with extremely low gestational ages.

STUDY DESIGN

We studied 850 infants at born at 23-27 weeks of gestation. We defined inflammatory protein elevation as the highest quartile of C-reactive protein (CRP), Interleukin (IL)-6, tumor necrosis factor-∝, or IL-8 on postnatal days 1, 7, and 14. We compared z-scores of weight, length, and head circumference at neonatal intensive care unit discharge or transfer between infants with vs without inflammatory protein elevation, adjusting in linear regression for birth size z-score, sex, gestational age, diet, comorbidities, medications, and length of hospitalization.

RESULTS

The mean gestational age was 25 weeks (range, 23-27 weeks) and birth weight z-score 0.14 (range, -2.73 to 3.28). Infants with a high CRP on day 7 had lower weights at discharge or transfer (-0.17 z-score; 95% CI, -0.27 to -0.06) than infants without CRP elevation, with similar results on day 14. Infants with CRP elevation on day 14 were also shorter (-0.21 length z-scores; 95% CI, -0.38 to -0.04), and had smaller head circumferences (-0.18 z-scores; 95% CI, -0.33 to -0.04) at discharge or transfer. IL-6 elevation on day 14 was associated with lower weight (-0.12; 95% CI, -0.22 to -0.02); IL-6 elevation on day 7 was associated with shorter length (-0.27; 95% CI, -0.43 to -0.12). Tumor necrosis factor-∝ and IL-8 elevation on day 14 were associated with a lower weight at discharge or transfer.

CONCLUSIONS

Postnatal systemic inflammation may contribute to impaired nutrient accretion during a critical period in development in infants with extremely low gestational ages.

Milk From Women Diagnosed With COVID-19 Does Not Contain SARS-CoV-2 RNA but Has Persistent Levels of SARS-CoV-2-Specific IgA Antibodies

Background

Limited data are available regarding the balance of risks and benefits from human milk and/or breastfeeding during and following maternal infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Objective

To investigate whether SARS-CoV-2 can be detected in milk and on the breast after maternal coronavirus disease 2019 (COVID-19) diagnosis; and characterize concentrations of milk immunoglobulin (Ig) A specific to the SARS-CoV-2 spike glycoprotein receptor binding domain (RBD) during the 2 months after onset of symptoms or positive diagnostic test.

Methods

Using a longitudinal study design, we collected milk and breast skin swabs one to seven times from 64 lactating women with COVID-19 over a 2-month period, beginning as early as the week of diagnosis. Milk and breast swabs were analyzed for SARS-CoV-2 RNA, and milk was tested for anti-RBD IgA.

Results

SARS-CoV-2 was not detected in any milk sample or on 71% of breast swabs. Twenty-seven out of 29 (93%) breast swabs collected after breast washing tested negative for SARS-CoV-2. Detection of SARS-CoV-2 on the breast was associated with maternal coughing and other household COVID-19. Most (75%; 95% CI, 70-79%; n=316) milk samples contained anti-RBD IgA, and concentrations increased (P=.02) during the first two weeks following onset of COVID-19 symptoms or positive test. Milk-borne anti-RBD IgA persisted for at least two months in 77% of women.

Conclusion

Milk produced by women with COVID-19 does not contain SARS-CoV-2 and is likely a lasting source of passive immunity via anti-RBD IgA. These results support recommendations encouraging lactating women to continue breastfeeding during and after COVID-19 illness.

Selective functional antibody transfer into the breastmilk after SARS-CoV-2 infection

Antibody transfer via breastmilk represents an evolutionary strategy to boost immunity in early life. Although severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibodies have been observed in the breastmilk, the functional quality of these antibodies remains unclear. Here, we apply systems serology to characterize SARS-CoV-2-specific antibodies in maternal serum and breastmilk to compare the functional characteristics of antibodies in these fluids. Distinct SARS-CoV-2-specific antibody responses are observed in the serum and breastmilk of lactating individuals previously infected with SARS-CoV-2, with a more dominant transfer of immunoglobulin A (IgA) and IgM into breastmilk. Although IgGs are present in breastmilk, they are functionally attenuated. We observe preferential transfer of antibodies capable of eliciting neutrophil phagocytosis and neutralization compared to other functions, pointing to selective transfer of certain functional antibodies to breastmilk. These data highlight the preferential transfer of SARS-CoV-2-specific IgA and IgM to breastmilk, accompanied by select IgG subpopulations, positioned to create a non-pathologic but protective barrier against coronavirus disease 2019 (COVID-19).

Targeting human milk fortification to improve very preterm infant growth and brain development: study protocol for Nourish, a single-center randomized, controlled clinical trial

Background

Human milk is recommended for very preterm infants, but its variable macronutrient content may contribute to undernutrition during a critical period in development. We hypothesize that individually targeted human milk fortification is more effective in meeting macronutrient requirements than the current standard of care.

Methods

We designed a single-center randomized, controlled trial enrolling 130 infants born < 31 completed weeks’ gestation. Participants will receive fortified maternal and/or pasteurized donor milk but no formula. For participants in the intervention group, milk will be individually fortified with protein and fat modulars to achieve target levels based on daily point-of-care milk analysis with mid-infrared spectroscopy, in addition to standard fortification. The study diet will continue through 36 weeks’ postmenstrual age (PMA). Clinical staff and parents will be masked to study group. Primary outcomes include: 1) body length and lean body mass by air displacement plethysmography at 36 weeks’ PMA; 2) quantitative magnetic resonance imaging-based measures of brain size and microstructure at term equivalent age; and 3) Bayley-IV scales at 2 years’ corrected age.

Discussion

We expect this trial to provide important data regarding the effectiveness of individually targeted human milk fortification in the neonatal intensive care unit (NICU).

Trial registration

NCT03977259, registered 6 June, 2019.

Association of Maternal Perinatal SARS-CoV-2 Infection With Neonatal Outcomes During the COVID-19 Pandemic in Massachusetts

IMPORTANCE

The incidence of mother-to-newborn SARS-CoV-2 transmission appears low and may be associated with biological and social factors. However, data are limited on the factors associated with neonatal clinical or viral testing outcomes.

OBJECTIVE

To ascertain the percentage of neonates who were born to mothers with positive SARS-CoV-2 test results during the birth hospitalization, the clinical and sociodemographic factors associated with neonatal test result positivity, and the clinical and virological outcomes for newborns during hospitalization and 30 days after discharge.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter cohort study included 11 academic or community hospitals in Massachusetts and mother-neonate dyads whose delivery and discharge occurred between March 1, 2020, and July 31, 2020. Eligible dyads were identified at each participating hospital through local COVID-19 surveillance and infection control systems. Neonates were born to mothers with positive SARS-CoV-2 test results within 14 days before to 72 hours after delivery, and neonates were followed up for 30 days after birth hospital discharge.

EXPOSURES

Hypothesized maternal risk factors in neonatal test result positivity included maternal COVID-19 symptoms, vaginal delivery, rooming-in practice, Black race or Hispanic ethnicity, and zip code-derived social vulnerability index. Delivery indicated by worsening maternal COVID-19 symptoms was hypothesized to increase the risk of adverse neonatal health outcomes.

MAIN OUTCOMES AND MEASURES

Primary outcomes for neonates were (1) positive SARS-CoV-2 test results, (2) indicators of adverse health, and (3) clinical signs and viral testing. Test result positivity was defined as at least 1 positive result on a specimen obtained by nasopharyngeal swab using a polymerase chain reaction-based method. Clinical and testing data were obtained from electronic medical records of nonroutine health care visits within 30 days after hospital discharge.

RESULTS

The cohort included 255 neonates (mean [SD] gestational age at birth, 37.9 [2.6] weeks; 62 [24.3%] with low birth weight or preterm delivery) with 250 mothers (mean [SD] age, 30.4 [6.3] years; 121 [48.4%] were of Hispanic ethnicity). Of the 255 neonates who were born to mothers with SARS-CoV-2 infection, 225 (88.2%) were tested for SARS-CoV-2 and 5 (2.2%) had positive results during the birth hospitalization. High maternal social vulnerability was associated with higher likelihood of neonatal test result positivity (adjusted odds ratio, 4.95; 95% CI, 1.53-16.01; P = .008), adjusted for maternal COVID-19 symptoms, delivery mode, and rooming-in practice. Adverse outcomes during hospitalization were associated with preterm delivery indicated by worsening maternal COVID-19 symptoms. Of the 151 newborns with follow-up data, 28 had nonroutine clinical visits, 7 underwent SARS-CoV-2 testing, and 1 had a positive result.

CONCLUSIONS AND RELEVANCE

The findings emphasize the importance of both biological and social factors in perinatal SARS-CoV-2 infection outcomes. Newborns exposed to SARS-CoV-2 were at risk for both direct and indirect adverse health outcomes, supporting efforts of ongoing surveillance of the virus and long-term follow-up.

Characterization of SARS-CoV-2 RNA, Antibodies, and Neutralizing Capacity in Milk Produced by Women with COVID-19

Whether mother-to-infant SARS-CoV-2 transmission can occur during breastfeeding and, if so, whether the benefits of breastfeeding outweigh this risk during maternal COVID-19 illness remain important questions. Using RT-qPCR, we did not detect SARS-CoV-2 RNA in any milk sample (n = 37) collected from 18 women following COVID-19 diagnosis. Although we detected evidence of viral RNA on 8 out of 70 breast skin swabs, only one was considered a conclusive positive result. In contrast, 76% of the milk samples collected from women with COVID-19 contained SARS-CoV-2-specific IgA, and 80% had SARS-CoV-2-specific IgG. In addition, 62% of the milk samples were able to neutralize SARS-CoV-2 infectivity in vitro, whereas milk samples collected prior to the COVID-19 pandemic were unable to do so. Taken together, our data do not support mother-to-infant transmission of SARS-CoV-2 via milk. Importantly, milk produced by infected mothers is a beneficial source of anti-SARS-CoV-2 IgA and IgG and neutralizes SARS-CoV-2 activity. These results support recommendations to continue breastfeeding during mild-to-moderate maternal COVID-19 illness.IMPORTANCE Results from prior studies assaying human milk for the presence of SARS-CoV-2, the causative virus of COVID-19, have suggested milk may act as a potential vehicle for mother-to-child transmission. Most previous studies are limited because they followed only a few participants, were cross-sectional, and/or failed to report how milk was collected and/or analyzed. As such, considerable uncertainty remains regarding whether human milk is capable of transmitting SARS-CoV-2 from mother to child. Here, we report that repeated milk samples collected from 18 women following COVID-19 diagnosis did not contain SARS-CoV-2 RNA; however, risk of transmission via breast skin should be further evaluated. Importantly, we found that milk produced by infected mothers is a source of anti-SARS-CoV-2 IgA and IgG and neutralizes SARS-CoV-2 activity. These results support recommendations to continue breastfeeding during mild-to-moderate maternal COVID-19 illness as milk likely provides specific immunologic benefits to infants.

Leveraging the Massachusetts perinatal quality collaborative to address the COVID-19 pandemic among diverse populations

OBJECTIVE

We leveraged the Massachusetts perinatal quality collaborative (PQC) to address the COVID-19 pandemic. Our goals were to: (1) implement perinatal practices thought to reduce mother-to-infant SARS-CoV-2 transmission while limiting disruption of health-promoting practices and (2) do so without inequities attributable to race/ethnicity, language status, and social vulnerability.

METHODS

Main outcomes were cesarean and preterm delivery, rooming-in, and breastfeeding. We examined changes over time overall and according to race/ethnicity, language status, and social vulnerability from 03/20-07/20 at 11 hospitals.

RESULTS

Of 255 mothers with SARS-CoV-2, 67% were black or Hispanic and 47% were non-English speaking. Cesarean decreased (49% to 35%), while rooming-in (55% to 86%) and breastfeeding (53% to 72%) increased. These changes did not differ by race/ethnicity, language, or social vulnerability.

CONCLUSIONS

Leveraging the Massachusetts PQC led to rapid changes in perinatal care during the COVID-19 crisis in a short time, representing a novel use of statewide PQC structures.

National Prevalence of Donor Milk Use Among Level 1 Nurseries

BACKGROUND AND OBJECTIVES

Donor milk use has increased among very preterm infants because of mounting evidence of health benefits; however, the extent that donor milk is used among healthy term infants in level 1 nurseries is unclear. We aimed to determine (1) national prevalence of and (2) hospital factors associated with donor milk use in level 1 nurseries.

METHODS

Among 3040 US birthing hospitals, we randomly selected hospitals from each of 4 US regions (119 in northeast, 120 in Midwest, 116 in west, and 103 in south) for a total of 458 hospitals. We surveyed the nursing leaders of these hospitals from October to December 2017 regarding routine use of donor milk in the level 1 nursery (yes or no). To estimate national prevalence, we weighted responses according to the number of birthing hospitals within each region. We examined relationships between routine donor milk use in the level 1 nursery and hospital characteristics using multivariable logistic regression.

RESULTS

In total, 214 of 458 (47%) nursing leaders responded. The national prevalence of routine donor milk use in level 1 nurseries was 17.6%. Eighty-five percent of donor milk programs were ≤5 years old. Donor milk use occurred more often in hospitals with ≥1500 annual births (41.7%), compared to ≤500 annual births (6.3%) (adjusted odds ratio 7.8; 95% confidence interval 1.8-34.4), and in the west (30.9%), compared to the northeast (10.5%) (adjusted odds ratio 4.1; 95% confidence interval [1.1-14.9]).

CONCLUSIONS

Although there is limited evidence to support donor milk for healthy infants in the nursery, nearly one-fifth of level 1 US nurseries routinely used donor milk in 2017.

COVID-19 and human milk: SARS-CoV-2, antibodies, and neutralizing capacity

Background

It is not known whether SARS-CoV-2 can be transmitted from mother to infant during breastfeeding, and if so whether the benefits of breastfeeding outweigh this risk. This study was designed to evaluate 1) if SARS-CoV-2 RNA can be detected in milk and on the breast of infected women, 2) concentrations of milk-borne anti-SARS-CoV-2 antibodies, and 3) the capacity of milk to neutralize SARS-CoV-2 infectivity.

Methods

We collected 37 milk samples and 70 breast swabs (before and after breast washing) from 18 women recently diagnosed with COVID-19. Samples were analyzed for SARS-CoV-2 RNA using RT-qPCR. Milk was also analyzed for IgA and IgG specific for the nucleocapsid protein, receptor binding domain (RBD), S2 subunit of the spike protein of SARS-CoV-2, as well as 2 seasonal coronaviruses using ELISA; and for its ability to neutralize SARS-CoV-2.

Results

We did not detect SARS-CoV-2 RNA in any milk sample. In contrast, SARS-CoV-2 RNA was detected on several breast swabs, although only one was considered conclusive. All milk contained SARS-CoV-2-specific IgA and IgG, and levels of anti-RBD IgA correlated with SARS-CoV-2 neutralization. Strong correlations between levels of IgA and IgG to SARS-CoV-2 and seasonal coronaviruses were noted.

Conclusions

Our data do not support maternal-to-child transmission of SARS-CoV-2 via milk; however, risk of transmission via breast skin should be further evaluated. Importantly, milk produced by infected mothers is a source of anti-SARS-CoV-2 IgA and IgG and neutralizes SARS-CoV-2 activity. These results support recommendations to continue breastfeeding during mild-to-moderate maternal COVID-19 illness.

The Nutritional Composition and Energy Content of Donor Human Milk: A Systematic Review

The American Academy of Pediatrics recommends donor human milk (DHM) as the preferred feeding strategy for preterm infants when the milk of the mother is unavailable, based on conclusive evidence of lower rates of necrotizing enterocolitis with DHM feedings compared with preterm infant formula. The nutritional composition of DHM may differ from maternal milk for many reasons including differences in maternal characteristics, milk collection methods, and the impact of donor milk banking practices. The purpose of this systematic review is to examine the literature regarding research on the fat, protein, carbohydrate, vitamin, and mineral composition of DHM obtained through nonprofit milk banks or commercial entities. PubMed, CINAHL, and Scopus databases were searched for articles published between 1985 and 30 April, 2019. In total, 164 abstracts were screened independently by 2 investigators, and 14 studies met all inclusion criteria. Studies were predominantly small (<50 samples) and measured macronutrients. Few studies assessed vitamins and minerals. Information bias was prevalent due to the use of a variety of analytical methods which influence accuracy and cross-study comparisons. Other sources of information bias included missing information regarding methods for protein and calorie assessment. Despite these limitations, existing research suggests the potential for 2-fold and greater differences in the fat, protein, and energy composition of DHM, with mean values for energy and fat often below clinical reference values expected for human milk. Further research is warranted regarding the nutritional composition of DHM, with a prioritization on measuring macronutrients and micronutrients using established reference methods.

Prevalence and predictors of donor milk programs among U.S. advanced neonatal care facilities

OBJECTIVE

(1) Determine national prevalence and predictors of donor milk programs among levels 2-4 advanced neonatal care facilities; (2) describe characteristics of donor milk programs.

STUDY DESIGN

We randomly selected 120 U.S. hospitals with levels 2-4 advanced neonatal care facilities among each of four U.S. regions and surveyed the medical directors from July 2017 to November 2017 regarding donor milk use. We weighted responses according to the number of birthing hospitals in each region.

RESULTS

Response rate was 213/480 (44%). Twenty-eight percent of level 2 and 88% of levels 3 and 4 neonatal care facilities had donor milk programs. Donor milk programs occurred more often in the South vs. Northeast (aOR 3.7 [1.1, 12.5] and less often in safety-net hospitals (≥75% Medicaid patients) vs. nonsafety-net hospitals (aOR 0.3 [0.1, 0.8]).

CONCLUSION

In 2017, the vast majority of levels 3 and 4 neonatal care facilities had donor milk programs but disparities existed according to the safety-net hospital status and region.

Associations of Growth and Body Composition with Brain Size in Preterm Infants

OBJECTIVE

To assess the association of very preterm infants' brain size at term-equivalent age with physical growth from birth to term and body composition at term.

STUDY DESIGN

We studied 62 infants born at <33 weeks of gestation. At birth and term, we measured weight and length and calculated body mass index. At term, infants underwent air displacement plethysmography to determine body composition (fat and fat-free mass) and magnetic resonance imaging to quantify brain size (bifrontal diameter, biparietal diameter, transverse cerebellar distance). We estimated associations of physical growth (Z-score change from birth to term) and body composition with brain size, adjusting for potential confounders using generalized estimating equations.

RESULTS

The median gestational age was 29 weeks (range, 24.0-32.9 weeks). Positive gains in weight and body mass index Z-score were associated with increased brain size. Each additional 100 g of fat-free mass at term was associated with larger bifrontal diameter (0.6 mm; 95% CI, 0.2-1.0 mm), biparietal diameter (0.7 mm; 95% CI, 0.3-1.1 mm), and transverse cerebellar distance (0.3 mm; 95% CI, 0.003-0.5 mm). Associations between fat mass and brain metrics were not statistically significant.

CONCLUSIONS

Weight and body mass index gain from birth to term, and lean mass-but not fat-at term, were associated with larger brain size. Factors that promote lean mass accrual among preterm infants may also promote brain growth.

Early-Life Predictors of Systolic Blood Pressure Trajectories From Infancy to Adolescence: Findings From Project Viva

Childhood blood pressure (BP) is a strong predictor of later risk of cardiovascular disease. However, few studies have assessed dynamic BP trajectories throughout the early-life period. We investigated the relationship between early-life factors and systolic BP (SBP) from infancy to adolescence using linear spline mixed-effects models among 1,370 children from Project Viva, a Boston, Massachusetts-area cohort recruited in 1999-2002. After adjusting for confounders and child height, we observed higher SBP in children exposed to gestational diabetes mellitus (vs. normoglycemia; age 3 years: β = 3.16 mm Hg (95% confidence interval (CI): 0.28, 6.04); age 6 years: β = 1.83 mm Hg (95% CI: 0.06, 3.60)), hypertensive disorders of pregnancy (vs. normal maternal BP; age 6 years: β = 1.39 mm Hg (95% CI: 0.10, 2.67); age 9 years: β = 1.84 mm Hg (95% CI: 0.34, 3.34); age 12 years: β = 1.70 mm Hg (95% CI: 0.48, 2.92)), higher neonatal SBP (per 10-mm Hg increase; age 3 years: β = 1.26 mm Hg (95% CI: 0.42, 2.09); age 6 years: β = 1.00 mm Hg (95% CI: 0.49, 1.51); age 9 years: β = 0.75 mm Hg (95% CI: 0.17, 1.33)), and formula milk in the first 6 months of life (vs. breast milk only; age 12 years: β = 2.10 mm Hg (95% CI: 0.46, 3.74); age 15 years: β = 3.52 mm Hg (95% CI: 1.40, 5.64); age 18 years: β = 4.94 mm Hg (95% CI: 1.88, 7.99)). Our findings provide evidence of programming of offspring SBP trajectories by gestational diabetes, hypertensive disorders of pregnancy, and formula milk intake and of neonatal BP being a potentially useful marker of childhood BP. These factors could be relevant in identifying children who are at risk of developing elevated BP.

Donor Milk Policies for Level 1 Newborn Care: A Descriptive Analysis

Background and Objectives: Providing pasteurized donor human milk (DHM) to healthy newborns is an emerging practice. The content of hospital policies that govern this practice is unknown. Materials and Methods: We collected policies from 15 Northeast U.S. hospitals through (1) a 2017 survey on DHM use and (2) an e-mail listserv of levels 1 and 2 newborn care staff maintained by a regional milk bank. Two authors reviewed each policy and identified how they addressed three predetermined themes: who is eligible to receive DHM, how DHM is used and described, and how lactation is supported. Responses were compared, discussed, and reconciled. Level 1 newborn care was defined as basic care for healthy newborns ≥35 weeks' gestation. Results: Thirteen of 15 policies stated criteria for DHM eligibility, most commonly as a bridge until mother's supply comes in (73%) or for infant medical conditions (67%). All required consent for DHM. Most did not limit number of days infants could receive DHM (60%). Nine specified that DHM be discarded 24 hours after thaw, whereas five recommended discarding at 48 hours. Although many (53%) policies endorsed human milk as the preferred diet for newborns, only 27% specifically endorsed DHM as the preferred supplementation type. Parent education (73%) was emphasized, but few (27%) discussed the importance of establishing mother's milk supply. Conclusions: Many DHM policies address eligibility criteria for receiving DHM and show how to provide DHM, but few address how to support lactation while DHM is provided, which may be crucial for optimizing long-term breastfeeding outcomes.

National Trends in the Provision of Human Milk at Hospital Discharge Among Very Low-Birth-Weight Infants

IMPORTANCE

Human milk confers important health benefits to very low-birth-weight (VLBW) infants (≤1500 g). The extent to which the use of human milk has changed over time and the factors associated with human milk use nationally in this population are poorly understood.

OBJECTIVES

To describe US trends in the provision of human milk at hospital discharge for VLBW infants during the past decade according to census region and maternal race/ethnicity, quantify associations of census region and maternal race/ethnicity with the provision of human milk at hospital discharge, and examine regional and state variations in any provision of human milk at hospital discharge among racial/ethnic groups.

DESIGN, SETTING, AND PARTICIPANTS

A cohort study was conducted of 346 248 infants, born at 23 to 29 weeks' gestation or with a birth weight of 401 to 1500 g, who were cared for at 802 US hospitals in the Vermont Oxford Network from January 1, 2008, to December 31, 2017. The US census region was categorized as West, Midwest, Northeast, and South (reference). Maternal race/ethnicity was categorized as non-Hispanic white (reference), non-Hispanic black, Hispanic, Asian and Pacific Islanders, and Native American.

MAIN OUTCOMES AND MEASURES

Any provision of human milk at hospital discharge, defined as the use of human milk as the only enteral feeding or the use of human milk in combination with fortifier or formula.

RESULTS

Of the 346 248 infants in the study (172 538 boys and 173 710 girls), 46.2% were non-Hispanic white, 30.1% were non-Hispanic black, 18.3% were Hispanic of any race, 4.7% were Asian and Pacific Islanders, and 0.8% were Native American. Any provision of human milk at hospital discharge increased steadily among all infants, from 44% in 2008 to 52% in 2017. There were increases across all US census regions and racial/ethnic groups. Any provision of human milk at hospital discharge was higher in the West (among singleton births: adjusted prevalence ratio, 1.32; 95% CI, 1.25-1.39; among multiple births: adjusted prevalence ratio, 1.28; 95% CI, 1.21-1.35) and Northeast (among singleton births: adjusted prevalence ratio, 1.11; 95% CI, 1.04-1.19; among multiple births: adjusted prevalence ratio, 1.11; 95% CI, 1.04-1.19), compared with the South, and was higher among Asian mothers (among singleton births: adjusted prevalence ratio, 1.21; 95% CI, 1.18-1.25; among multiple births: adjusted prevalence ratio, 1.12; 95% CI, 1.09-1.15) and lower among Hispanic (among singleton births: adjusted prevalence ratio, 0.98; 95% CI, 0.96-1.01; among multiple births: adjusted prevalence ratio, 0.88; 95% CI, 0.86-0.91), Native American (among singleton births: adjusted prevalence ratio, 0.64; 95% CI, 0.59-0.70; among multiple births: adjusted prevalence ratio, 0.59; 95% CI, 0.50-0.69), and non-Hispanic black mothers (among singleton births: adjusted prevalence ratio, 0.67; 95% CI, 0.65-0.70; among multiple births: adjusted prevalence ratio, 0.57; 95% CI, 0.54-0.60), compared with non-Hispanic white mothers. These results were robust to adjustment for birth year and infant characteristics. Wide regional and state variations were found in any provision of human milk at hospital discharge.

CONCLUSIONS AND RELEVANCE

Overall prevalence of any provision of human milk at hospital discharge among VLBW infants has steadily increased during the past decade. Disparities by US region and race/ethnicity in the provision of human milk exist and have not diminished over time.

Macronutrient Analysis of Modified-Fat Breast Milk Produced by 3 Methods of Fat Removal

BACKGROUND

Infants with chylothorax after congenital heart disease surgery are commonly treated using modified-fat breast milk. The effect of fat removal on breast milk macronutrients remains unclear. We compared macronutrient content of breast milk with breast milk skimmed using 3 methods, including a novel device, a cream separator.

METHODS

Thawed frozen breast milk samples from 30 women were defatted using refrigerated centrifuge, cream separator, and manual separation after refrigeration. We used standard assays to measure energy, protein, and fat content of breast milk samples.

RESULTS

All fat removal methods yielded skimmed breast milk with substantially lower fat and energy content. Mean energy content in breast milk skimmed by centrifuge (36.7 [SD 3.6] kcal/100 mL) was similar to that from cream separator (38.8 [3.5] kcal/100 mL). Both centrifuge and cream separator methods removed almost all fat and substantially more fat than the manual fat removal method. For unprocessed milk, energy and fat content estimated by creamatocrit was similar to reference method measurements; in skimmed milk, the creamatocrit significantly overestimated fat content. Mean protein content of skimmed breast milk was similar to unprocessed breast milk (mean 1.25 [0.31] g/100 mL).

CONCLUSION

Breast milk fat removal did not significantly alter protein levels. In skimmed breast milk, the overestimation of fat content using creamatocrit method suggests a need for more accurate bedside methods to assess macronutrient content. The similar macronutrient composition of breast milk skimmed by cream separator and centrifuge suggests the potential for cream separator use as a new, portable defatting method for hospitals and families.

A 2017 US Reference for Singleton Birth Weight Percentiles Using Obstetric Estimates of Gestation

OBJECTIVE

To provide an updated birth weight-for-gestational age (BW-for-GA) reference in the United States by using the most recent, nationally representative birth data with obstetric estimates of gestational age (GA).

METHODS

We abstracted 3 285 552 singleton births between 22 and 42 weeks' gestation with nonmissing race and/or ethnicity, infant sex, parity, birth weight, and obstetric estimate of GA from the 2017 US natality files. We used 2 techniques (nonlinear, resistant smoothing [4253H] and lambda-mu-sigma) to derive smoothed BW-for-GA curves and compared resulting BW-for-GA cut-points at the third, 10th, 90th, and 97th percentiles with US references from 1999 to 2009.

RESULTS

The smoothed BW-for-GA curves from both techniques overlapped considerably with each other, with strong agreements seen between the 2 techniques (>99% agreement; κ-statistic >0.9) for BW-for-GA cut-points at the third, 10th, 90th, and 97th percentiles across all GAs. Cut-points from 2017 using the lambda-mu-sigma method captured 9.8% to 10.2% of births <10th and >90th percentiles and 2.6% to 3.3% of births below the third and above the 97th percentile across all GAs. However, cut-points from US references in 1999 and 2009 (when GA was based on last menstrual period) captured a much larger range of proportions of 2017 births at these thresholds, especially among preterm and postterm GA categories.

CONCLUSIONS

We have provided an updated BW-for-GA reference in the United States using the most recent births with obstetric estimates of GA and information to calculate continuous measures of birth size that are sex or parity specific.

Addressing Disparities in Mother's Milk for VLBW Infants Through Statewide Quality Improvement

OBJECTIVES

Among very low birth weight infants born from January 2015 to December 2017, the Massachusetts statewide quality improvement collaborative aimed to increase provision of (1) any mother's milk at discharge or transfer from a baseline of 63% to ≥75%, (2) exclusive mother's milk at discharge or transfer from a baseline of 45% to ≥55%, and (3) to reduce racial and ethnic disparities in provision of mother's milk.

METHODS

We used the Institute for Healthcare Improvement Breakthrough Series framework in which our main process measures were receipt of prenatal education regarding human milk education, first milk expression within 6 hours after birth, and any skin-to-skin care on 4 weekly audit days in the first month. We examined changes over time among all very low birth weight infants and for 3 racial and ethnic subgroups (non-Hispanic white, non-Hispanic black, and Hispanic) using control and run charts, respectively.

RESULTS

Of 1670 infants eligible to receive mother's milk at 9 hospitals, 43% of their mothers were non-Hispanic white, 19% were non-Hispanic black, 19% were Hispanic, 11% were of other races or ethnicities, and 7% were unknown. Hospital teams conducted 69 interventions. We found improvement in all 3 process measures but not for our main outcomes. Improvements in process measures were similar among racial and ethnic subgroups. Hospitals varied substantially in the rate of any mother's milk at discharge or transfer according to race and ethnicity.

CONCLUSIONS

Our collaborative achieved similar improvements in process measures focused within the first month of hospitalization among all racial and ethnic subgroups. Reduction in racial and ethnic disparities in mother's milk at discharge was not reached. Future efforts will focus on factors that occur later in the hospitalization.

Diet, weight gain, and head growth in hospitalized US very preterm infants: a 10-year observational study

BACKGROUND

The benefits of human milk for hospitalized preterm infants are well documented, but the extent to which current human milk diets adequately support growth is uncertain.

OBJECTIVES

1) To quantify differences in weight gain and head growth between very preterm infants fed human milk compared with infant formula; and 2) to describe trends in the magnitude of these differences over time.

METHODS

We studied infants from 777 US NICUs in the Vermont Oxford Network database. We included all surviving infants 23-29 weeks of gestation or 401-1500 g birth weight (maximum gestational age 32 wk) and excluded infants discharged >42 weeks of gestation or with congenital anomalies. In diet-growth analyses, we included infants born 2012-2016 (n = 138,703) to reflect current practice. In trend analyses, we included a 10-y cohort (n = 263,367). We categorized diet at NICU discharge/transfer as: 1) human milk only (no formula or fortifier); 2) human milk with formula or fortifier (mixed); or 3) infant formula only. Outcomes were weight and head circumference z-score change from birth to discharge relative to a fetal reference.

RESULTS

Diet at discharge/transfer was human milk only for 18,274 (6.6%), mixed for 121,621 (44%), and formula only for 137,067 (49%). Weight deviated more from the fetal reference for infants fed both human milk diets compared with formula only (weight z-score change for infants fed human milk only, -0.88; mixed, -0.82; formula only -0.80; P < 0.0001 for diet overall). There were also differences by diet in head z-score change (human milk only, -0.52; mixed, -0.49; formula only, -0.45; P < 0.0001 for diet overall). The magnitude of these differences has diminished substantially over 10 y.

CONCLUSIONS

Very preterm infants receiving human milk compared with infant formula diets have a slower weight gain and head growth at hospital discharge.

Association of Weight for Length vs Body Mass Index During the First 2 Years of Life With Cardiometabolic Risk in Early Adolescence

Importance

The American Academy of Pediatrics currently recommends weight for length (WFL) for assessment of weight status in children younger than 2 years but body mass index (BMI) for children older than 2 years. However, the clinical implications of using WFL vs BMI in children younger than 2 years as an indicator of future health outcomes remains understudied.

Objective

To compare associations of overweight based on WFL vs BMI in children younger than 2 years with cardiometabolic outcomes during early adolescence.

Design, Setting, and Participants

This prospective study of birth cohorts in the United States (Project Viva) and Belarus (Promotion of Breastfeeding Intervention Trial [PROBIT]) performed from June 1, 1996, to November 31, 2002, included 13 666 children younger than 2 years.

Main Exposures

Overweight defined as Centers for Disease Control and Prevention (CDC) WFL in the 95th percentile or greater, World Health Organization (WHO) WFL in the 97.7th percentile or greater, or WHO BMI in the 97.7th percentile or greater at 6, 12, 18, or 24 months of age.

Main Outcomes and Measures

Primary outcomes were fat mass index, insulin resistance, metabolic risk score, and obesity during early adolescence. Secondary outcomes were height and BMI z scores, sum of skinfolds, waist circumference, and systolic blood pressure during early adolescence.

Results

The study included 919 children (mean [SD] age, 12.9 [0.9] years; 460 [50.1%] male; and 598 [65.1%] white) from Project Viva and 12 747 children (mean [SD] age, 11.5 [0.5] years; 6204 [48.7%] male; and 12 747 [100%] white) from PROBIT. During 6 to 24 months of age, in Project Viva, 206 children (22.4%) were overweight at any of the 4 times points according to the CDC WFL, 160 (17.4%) according to WHO WFL, and 161 (17.5%) according to WHO BMI cut points. In PROBIT, 3715 children (29.1%) were overweight at any of the 4 time points according to the CDC WFL, 3069 (24.1%) according to WHO WFL, and 3125 (24.5%) according to WHO BMI cut points. After maternal and child characteristics were adjusted for, being ever overweight (vs never overweight) during 6 to 24 months of age was associated with higher likelihood of adverse cardiometabolic risk markers during early adolescence, but associations did not differ substantially across WFL and BMI cut points in either cohort. For example, for fat mass index in Project Viva, β = 0.9 (95% CI, 0.5-1.4) for the CDC WFL, β = 1.1 (95% CI, 0.6-1.6) for WHO WFL, and β = 1.4 (95% CI, 0.9-1.9) for WHO BMI. For PROBIT, β = 0.5 (95% CI, 0.4-0.6) for the CDC WFL, β = 0.6 (95% CI, 0.5-0.7) for WHO WFL, and β = 0.6 (95% CI, 0.5-0.6) for WHO BMI. Neither growth metric in infancy was superior over the others based on F statistics (Project Viva: 17.1-17.8; PROBIT: 87.1-88.7). Findings were similar for insulin resistance, metabolic risk score, obesity, and secondary outcomes.

Conclusions and Relevance

Choice of WFL vs BMI to define overweight during the first 2 years of life may not greatly affect the association with cardiometabolic outcomes during early adolescence. The findings appear to have important implications for investigators seeking to use BMI as a growth metric for epidemiologic research and for practitioners monitoring the weight status of children younger than 2 years.

Validity of Body Mass Index as a Measure of Adiposity in Infancy

OBJECTIVES

To assess the validity of body mass index (BMI) and age- and sex-standardized BMI z-score (BMIZ) as surrogates for adiposity (body fat percentage [BF%], fat mass, and fat mass index [kg/m²]) at 3 time points in infancy (1, 4, and 7 months) and to assess the extent to which the change in BMIZ represents change in adiposity.

STUDY DESIGN

We performed a secondary analysis of 447 full-term infants in a previous trial of maternal vitamin D supplementation during lactation. Study staff measured infant anthropometrics and assessed body composition with dual-energy x-ray absorptiometry at 1, 4, and 7 months of age. We calculated Spearman correlations (r_s) among BMI, BMIZ, and adiposity at each time point, and between change in BMIZ and change in adiposity between time points.

RESULTS

Infants (N = 447) were 52% male, 38% white, 31% black, and 29% Hispanic. The BMIZ was moderately correlated with BF% (r_s = 0.43, 0.55, 0.48 at 1, 4, and 7 months of age, respectively). BMIZ correlated more strongly with fat mass and fat mass index, particularly at 4 and 7 months of age (fat mass r_s = 0.72-0.76; fat mass index r_s = 0.75-0.79). Changes in BMIZ were moderately correlated with adiposity changes from 1 to 4 months of age (r_s = 0.44 with BF% change; r_s = 0.53 with fat mass change), but only weakly correlated from 4 to 7 months of age (r_s = 0.21 with BF% change; r_s = 0.27 with fat mass change).

CONCLUSIONS

BMIZ is moderately correlated with adiposity in infancy. Changes in BMIZ are a poor indicator of adiposity changes in later infancy. BMI and BMIZ are limited as surrogates for adiposity and especially adiposity changes in infancy.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00412074.

Determinants of physical activity frequency and provider advice during pregnancy

Background

Our aims were to (1) describe the frequency of physical activity and prenatal healthcare provider advice about physical activity during pregnancy and (2) examine determinants and correlates of 3rd trimester physical activity and receipt of physical activity advice.

Methods

We analyzed data from the 2008 Pregnancy Risk Assessment Monitoring System. We studied 2669 women from North Carolina and Colorado with data on physical activity frequency in the 3 months prior to pregnancy and during the 3rd trimester and 1584 women from Oklahoma with data on provider advice regarding physical activity during pregnancy. Respondents reported physical activity, defined as 30 min or more of exercise/physical activity (excluding vocationally related activity), in in these categories: <1 day/week, 1-4 days/week, and ≥5 days/week. We defined adherence to American College of Obstetrics & Gynecology (ACOG) criteria as physical activity ≥5 days/week in the 3rd trimester. We performed logistic regression analyses weighted for sampling and adjusted for socio-demographic factors.

Results

Forty-two percent of women in North Carolina and Colorado reported 3rd trimester physical activity <1 day/week, 42% 1-4 days/week, 9% ≥5 days/week; 7% reported being told not to exercise. Seventy-two percent of women in Oklahoma reported receiving physical activity advice from a prenatal care provider. Low activity frequency (<1 day/week) prior to pregnancy was strongly associated with low likelihood of ACOG guideline adherence in the 3rd trimester (aOR 0.10, 95% CU 0.04, 0.30 vs. 1–4 days/week). Underweight women were more likely to adhere to ACOG guidelines than normal weight women (aOR 2.27, 95% CI 1.36, 3.79). Overweight women were more likely to receive physical activity advice (aOR 2.9, 95% CI 1.3, 6.3 vs. normal weight), but obese women were not (aOR 0.65, 95% CI 0.4, 1.2).

Conclusions

Few women meet ACOG guideline criteria for physical activity during pregnancy. Improving physical activity and weight status prior to pregnancy may improve activity levels during pregnancy. Nearly one third did not receive advice about physical activity during prenatal care. Obese women were no more likely to receive advice than their normal weight counterparts, indicating the need for targeted physical activity counseling in this population.

Associations of infant feeding with trajectories of body composition and growth

Background: The extent to which breastfeeding is protective against later-life obesity is controversial. Little is known about differences in infant body composition between breastfed and formula-fed infants, which may reflect future obesity risk.Objective: We aimed to assess associations of infant feeding with trajectories of growth and body composition from birth to 7 mo in healthy infants.Design: We studied 276 participants from a previous study of maternal vitamin D supplementation during lactation. Mothers used monthly feeding diaries to report the extent of breastfeeding. We measured infants' anthropometrics and used dual-energy X-ray absorptiometry to assess body composition at 1, 4, and 7 mo. We compared changes in infant size (z scores for weight, length, and body mass index [BMI (in kg/m²)]) and body composition (fat and lean mass, body fat percentage) between predominantly breastfed and formula-fed infants, adjusting in linear regression for sex, gestational age, race/ethnicity, maternal BMI, study site, and socioeconomic status.Results: In this study, 214 infants (78%) were predominantly breastfed (median duration: 7 mo) and 62 were exclusively formula fed. Formula-fed infants had lower birth-weight z scores than breastfed infants (-0.22 ± 0.86 and 0.16 ± 0.88, respectively; P < 0.01) but gained more in weight and BMI through 7 mo of age (weight z score difference: 0.37; 95% CI: 0.04, 0.71; BMI z score difference: 0.35; 95% CI: 0, 0.69), with no difference in linear growth (z score difference: 0.05; 95% CI: -0.24, 0.34). Formula-fed infants gained more lean mass (difference: 303 g; 95% CI: 137, 469 g) than breastfed infants, but not fat mass (difference: -42 g; 95% CI: -299, 215 g).Conclusions: Formula-fed infants gained weight more rapidly and out of proportion to linear growth than did predominantly breastfed infants. These differences were attributable to greater accretion of lean mass, rather than fat mass. Any later obesity risk associated with infant feeding does not appear to be explained by differential adiposity gains in infancy.

An observational cohort study of weight- and length-derived anthropometric indicators with body composition at birth and 5 mo: the Healthy Start study

Background: Despite widespread use of weight- and length-based anthropometric indexes as proxies for adiposity, little is known regarding the extent to which they correspond with fat mass (FM) or fat-free mass (FFM) during infancy.Objective: This study aimed to examine associations of 3 derived indicators-weight-for-age z score (WFAZ), weight-for-length score (WFLZ), and body mass index z score (BMIZ)-with FM, percentage of FM, and FFM measured by air-displacement plethysmography during the first 5 mo of life.Design: Applying prospectively collected data from 1027 infants in a Colorado prebirth cohort, we used multivariate regression to evaluate associations between the derived indicators and body composition at birth and at 5 mo, and with change (Δ) during follow-up.Results: At birth, all 3 derived indicators were more strongly associated with FFM than with FM. Each unit of WFAZ corresponded with 0.342 kg FFM (95% CI: 0.331, 0.351 kg FFM), compared with 0.121 kg FM (95% CI: 0.114, 0.128 kg FM) (P < 0.0001); similar trends were observed for WFLZ and BMIZ. By 5 mo, WFLZ and BMIZ were more strongly associated with FM than with FFM, whereas WFAZ correlated similarly with the 2 components of body composition. ΔWFLZ and ΔBMIZ were both more strongly related to ΔFM than to ΔFFM; however, a direct comparison of the 2 indexes with respect to change in the percentage of FM indicated that ΔBMIZ was the optimal proxy of adiposity gain (P < 0.0001, pairwise difference).Conclusions: Weight- and length-based indexes are poor surrogates for newborn adiposity. However, at 5 mo, WFLZ and BMIZ are suitable proxies of FM. When assessing adiposity gain, ΔBMIZ is the best indicator of fat accrual during the first 5 postnatal months. This trial was registered at clinicaltrials.gov as NCT02273297.

The impact of preterm birth <37 weeks on parents and families: a cross-sectional study in the 2 years after discharge from the neonatal intensive care unit

BACKGROUND

Little is known about the quality of life of parents and families of preterm infants after discharge from the neonatal intensive care unit (NICU). Our aims were (1) to describe the impact of preterm birth on parents and families and (2) and to identify potentially modifiable determinants of parent and family impact.

METHODS

We surveyed 196 parents of preterm infants <24 months corrected age in 3 specialty clinics (82% response rate). Primary outcomes were: (1) the Impact on Family Scale total score; and (2) the Infant Toddler Quality of Life parent emotion and (3) time limitations scores. Potentially modifiable factors were use of community-based services, financial burdens, and health-related social problems. We estimated associations of potentially modifiable factors with outcomes, adjusting for socio-demographic and infant characteristics using linear regression.

RESULTS

Median (inter-quartile range) infant gestational age was 28 (26-31) weeks. Higher Impact on Family scores (indicating worse effects on family functioning) were associated with taking ≥3 unpaid hours/week off from work, increased debt, financial worry, unsafe home environment and social isolation. Lower parent emotion scores (indicating greater impact on the parent) were also associated with social isolation and unpaid time off from work. Lower parent time limitations scores were associated with social isolation, unpaid time off from work, financial worry, and an unsafe home environment. In contrast, higher parent time limitations scores (indicating less impact) were associated with enrollment in early intervention and Medicaid.

CONCLUSIONS

Interventions to reduce social isolation, lessen financial burden, improve home safety, and increase enrollment in early intervention and Medicaid all have the potential to lessen the impact of preterm birth on parents and families.

Breast Milk Feeding, Brain Development, and Neurocognitive Outcomes: A 7-Year Longitudinal Study in Infants Born at Less Than 30 Weeks' Gestation

OBJECTIVES

To determine the associations of breast milk intake after birth with neurological outcomes at term equivalent and 7 years of age in very preterm infants

STUDY DESIGN

We studied 180 infants born at <30 weeks' gestation or <1250 grams birth weight enrolled in the Victorian Infant Brain Studies cohort from 2001-2003. We calculated the number of days on which infants received >50% of enteral intake as breast milk from 0-28 days of life. Outcomes included brain volumes measured by magnetic resonance imaging at term equivalent and 7 years of age, and cognitive (IQ, reading, mathematics, attention, working memory, language, visual perception) and motor testing at 7 years of age. We adjusted for age, sex, social risk, and neonatal illness in linear regression.

RESULTS

A greater number of days on which infants received >50% breast milk was associated with greater deep nuclear gray matter volume at term equivalent age (0.15 cc/d; 95% CI, 0.05-0.25); and with better performance at age 7 years of age on IQ (0.5 points/d; 95% CI, 0.2-0.8), mathematics (0.5; 95% CI, 0.1-0.9), working memory (0.5; 95% CI, 0.1-0.9), and motor function (0.1; 95% CI, 0.0-0.2) tests. No differences in regional brain volumes at 7 years of age in relation to breast milk intake were observed.

CONCLUSION

Predominant breast milk feeding in the first 28 days of life was associated with a greater deep nuclear gray matter volume at term equivalent age and better IQ, academic achievement, working memory, and motor function at 7 years of age in very preterm infants.

Birth Size, Early Life Weight Gain, and Midchildhood Cardiometabolic Health

OBJECTIVE

To examine associations of birth size and weight gain during 4 early-life age intervals with midchildhood adiposity and metabolic profile and to evaluate for an interaction between birth size and early-life weight gain.

STUDY DESIGN

Using data from 963 participants of Project Viva, a US prebirth cohort, we used multivariable linear regression to examine relations of birth size (tertiles of birthweight-for-gestational-age z-score) and weight gain (body mass index z-score [BMIZ] change) during 4 age intervals (birth-6 months, 6 months-1 year, 1-2 years, 2-3 years) with body composition and metabolic biomarkers during midchildhood (6.6-10.7 years).

RESULTS

After accounting for confounders and previous growth, greater BMIZ change during all 4 age intervals corresponded with higher midchildhood adiposity, with larger effect sizes for later (1-2 years and 2-3 years) vs earlier (birth-6 months and 6 months-1 year) time frames. We observed effect modification by birth size for the birth-6 months and 6 months-1 year intervals. Greater birth-6 months BMIZ change was associated with higher overall adiposity (0.40 [95% CI 0.29, 0.51] kg dual x-ray absorptiometry total fat mass per z-score) among children in the highest birth size tertile. Similar associations were observed for central adiposity. Each increment in 6 months-1 year BMIZ change corresponded with 0.55 (0.05, 1.05) units higher homeostatic model assessment of insulin resistance and 2.68 (0.96, 4.40) ng/mL higher leptin among the smallest infants.

CONCLUSIONS

BMIZ gain after 1 year is associated with greater midchildhood adiposity regardless of birth size, whereas the long-term influence of weight gain during the first postnatal year may depend on size at birth. Future studies are warranted to validate findings and examine relations with conventional birth size cut-offs.

Preterm infant growth and asthma at age 8 years

OBJECTIVES

To examine associations of gain in body mass index (BMI) and linear growth from term to 18 months with asthma at age 8 years in a cohort of preterm infants. We hypothesised that rapid BMI gain would increase asthma risk, whereas rapid linear growth would be protective.

DESIGN

Observational secondary analysis of data from the Infant Health and Development Program.

SETTING

8 centres in the USA.

PATIENTS

863 preterm (≤37 weeks), low birthweight (≤2500 g) children.

MAIN EXPOSURE VARIABLES

Gain in BMI and linear growth from term to 4 months, 4-12 months and 12-18 months, in z-scores.

MAIN OUTCOME MEASURE

Asthma at age 8 years, assessed by parent report of the child ever receiving the diagnosis from a doctor.

RESULTS

At age 8 years, 149 (17%) had ever been diagnosed with asthma. Adjusting for maternal and child factors in logistic regression, for each additional z-score gain in BMI from term to 4 months, odds of asthma at age 8 years were higher (OR 1.3, 95% CI 1.1 to 1.5); findings were similar for BMI gain from 4-12 months. More rapid linear growth from term to 4 months was not associated with lower odds of asthma (OR 1.1, 95% CI 0.9 to 1.3), with similar findings for 4-12 months and 12-18 months.

CONCLUSIONS

More rapid BMI gain in the 1st year of life was associated with higher odds of asthma, whereas linear growth did not appear protective. Our results add to mounting evidence that excess weight gain after term may be harmful to preterm infants.

Early Weight Gain, Linear Growth, and Mid-Childhood Blood Pressure: A Prospective Study in Project Viva

In recent years, the prevalence of hypertension and prehypertension increased markedly among children and adolescents, highlighting the importance of identifying determinants of elevated blood pressure early in life. Low birth weight and rapid early childhood weight gain are associated with higher future blood pressure. However, few studies have examined the timing of postnatal weight gain in relation to later blood pressure, and little is known regarding the contribution of linear growth. We studied 957 participants in Project Viva, an ongoing US prebirth cohort. We examined the relations of gains in body mass index z-score and length/height z-score during 4 early life age intervals (birth to 6 months, 6 months to 1 year, 1 to 2 years, and 2 to 3 years) with blood pressure during mid-childhood (6-10 years) and evaluated whether these relations differed by birth size. After accounting for confounders, each additional z-score gain in body mass index during birth to 6 months and 2 to 3 years was associated with 0.81 (0.15, 1.46) and 1.61 (0.33, 2.89) mm Hg higher systolic blood pressure, respectively. Length/height gain was unrelated to mid-childhood blood pressure, and there was no evidence of effect modification by birth size for body mass index or length/height z-score gain. Our findings suggest that more rapid gain in body mass index during the first 6 postnatal months and in the preschool years may lead to higher systolic blood pressure in mid-childhood, regardless of size at birth. Strategies to reduce accrual of excess adiposity during early life may reduce mid-childhood blood pressure, which may also impact adult blood pressure and cardiovascular health.

Weight Status in the First 2 Years of Life and Neurodevelopmental Impairment in Extremely Low Gestational Age Newborns

OBJECTIVE

To examine the extent to which weight gain and weight status in the first 2 years of life relate to the risk of neurodevelopmental impairment in extremely preterm infants.

STUDY DESIGN

In a cohort of 1070 infants born between 23 and 27 weeks' gestation, we examined weight gain from 7-28 days of life (in quartiles) and weight z-score at 12 and 24 months corrected age (in 4 categories: <-2; ≥-2, <-1; ≥1, <1; and ≥1) in relation to these adverse neurodevelopmental outcomes: Bayley-II mental development index <55, Bayley-II psychomotor development index <55, cerebral palsy, Gross Motor Function Classification System ≥1 (cannot walk without assistance), microcephaly. We adjusted for confounders in logistic regression, stratified by sex, and performed separate analyses including the entire sample, and excluding children unable to walk without assistance (motor impairment).

RESULTS

Weight gain in the lowest quartile from 7-28 days was not associated with higher risk of adverse outcomes. Children with a 12-month weight z-score <-2 were at increased risk for all adverse outcomes in girls, and for microcephaly and Gross Motor Function Classification System ≥1 in boys. However, excluding children with motor impairment attenuated all associations except that of weight z-score <-2 with microcephaly in girls. Similarly, most associations of low weight z-score at 24 months with adverse outcomes were attenuated with exclusion of children with motor impairment.

CONCLUSION

Excluding children who have gross motor impairment appears to eliminate the association of low weight status with neurodevelopmental impairments at 2 years in extremely preterm infants.

No difference in urinary iodine concentrations between Boston-area breastfed and formula-fed infants

BACKGROUND

Thyroid hormone is essential for normal mental and physical development in infancy and childhood and is dependent on adequate iodine intake. During the first few months of life, infants are reliant on breastmilk and/or infant formula as their sole sources of dietary iodine. The iodine status of U.S. infants has not been well studied.

METHODS

This was a cross-sectional study of 95 breastfed and/or formula-fed infants less than 3 months of age in the Boston area. We measured iodine content from infants' single spot urine samples and assessed associations with infant feeding type as well as maternal demographic data, salt and multivitamin use, smoking status, and diet.

RESULTS

The median infant urine iodine concentration was 197.5 μg/L (range 40-897.5 μg/L). Median infant urine iodine concentrations were similar between infants who were exclusively breastfed (n=39, 203.5 μg/L; range 61.5-395.5 μg/L), formula-fed (n=44, 182.5 μg/L; range 40-897.5 μg/L), and mixed (n=10, 197.8 μg/L; range 123-592.5) (p=0.88). There were no significant correlations of infant urinary iodine with maternal salt or multivitamin use (regularly or in the past 24 hours), active or secondhand cigarette smoke exposures, infant weight, infant length, or recent maternal ingestion of common iodine-containing foods, although the correlations with iodine-containing foods are difficult to accurately determine due to the small sample sizes of these variables.

CONCLUSIONS

Both breastfed and formula-fed infants less than 3 months of age in the Boston area were generally iodine sufficient. Larger studies are needed to confirm these observations among infants nationwide and elucidate other factors that may contribute to infant iodine nutrition.

Prepregnancy body mass index and risk of preterm birth: association heterogeneity by preterm subgroups

BACKGROUND

To evaluate the association between prepregnancy body mass index (BMI) is associated with early vs. late and medically-induced vs. spontaneous preterm birth (PTB) subtypes.

METHODS

Using data from the Boston Birth Cohort, we examined associations of prepregnancy BMI with 189 early (<34 completed weeks) and 277 late (34-36 completed weeks) medically-induced PTBs and 320 early and 610 late spontaneous PTBs vs. 3281 term births (37-44 weeks) in multinomial regression. To assess for mediation by important pregnancy complications, we performed sequential models with and without hypertensive disorders of pregnancy, chorioamnionitis, and gestational diabetes.

RESULTS

Prevalence of prepregnancy obesity (BMI ≥ 30.0 kg/m2) was 28% among mothers with medically-induced PTBs, 18% among mothers with spontaneous PTBs, and 18% among mothers with term births (p = <0.001). After adjustment for demographic and known risk factors for PTB, prepregnancy obesity was associated with higher odds of both early [OR 1.78 (1.19, 2.66)] and late [OR 1.49 (1.09, 2.04)] medically-induced PTB. These effect estimates were attenuated with inclusion of hypertensive disorders of pregnancy and gestational diabetes. For spontaneous deliveries, prepregnancy obesity was associated with decreased odds of PTB (0.76 [0.58, 0.98]) and underweight was nearly associated with increased odds of PTB (1.46 [0.99, 2.16]).

CONCLUSION

Prepregnancy obesity is associated with higher risk of medically-induced, but not spontaneous PTB. Hypertensive disorders of pregnancy and gestational diabetes appear to partially explain the association between prepregnancy obesity and early and late medically-induced PTB.

Cohort profile: project viva

We established Project Viva to examine prenatal diet and other factors in relation to maternal and child health. We recruited pregnant women at their initial prenatal visit in eastern Massachusetts between 1999 and 2002. Exclusion criteria included multiple gestation, inability to answer questions in English, gestational age ≥22 weeks at recruitment and plans to move away before delivery. We completed in-person visits with mothers during pregnancy in the late first (median 9.9 weeks of gestation) and second (median 27.9 weeks) trimesters. We saw mothers and children in the hospital during the delivery admission and during infancy (median age 6.3 months), early childhood (median 3.2 years) and mid-childhood (median 7.7 years). We collected information from mothers via interviews and questionnaires, performed anthropometric and neurodevelopmental assessments and collected biosamples. We have collected additional information from medical records and from mailed questionnaires sent annually to mothers between in-person visits and to children beginning at age 9 years. From 2341 eligible women, there were 2128 live births; 1279 mother-child pairs provided data at the mid-childhood visit. Primary study outcomes include pregnancy outcomes, maternal mental and cardiometabolic health and child neurodevelopment, asthma/atopy and obesity/cardiometabolic health. Investigators interested in learning more about how to obtain Project Viva data can contact Project_Viva@hphc.org.

Preterm infant linear growth and adiposity gain: trade-offs for later weight status and intelligence quotient

OBJECTIVE

To examine trade-offs between cognitive outcome and overweight/obesity in preterm-born infants at school age and young adulthood in relation to weight gain and linear growth during infancy.

STUDY DESIGN

We studied 945 participants in the Infant Health and Development Program, an 8-center study of preterm (≤37 weeks gestational age), low birth weight (≤2500 g) infants from birth to age 18 years. Adjusting for maternal and child factors in logistic regression, we estimated the odds of overweight/obesity (body mass index [BMI] ≥85th percentile at age 8 or ≥25 kg/m(2) at age 18) and in separate models, low IQ (<85) per z-score changes in infant length and BMI from term to 4 months, from 4 to 12 months, and from 12 to 18 months.

RESULTS

More rapid linear growth from term to 4 months was associated with lower odds of IQ <85 at age 8 years (OR, 0.82; 95% CI, 0.70-0.96), but higher odds of overweight/obesity (OR, 1.27; 95% CI, 1.05-1.53). More rapid BMI gain in all 3 infant time intervals was also associated with higher odds of overweight/obesity, and BMI gain from 4-12 months was associated with lower odds of IQ <85 at age 8. Results at age 18 were similar.

CONCLUSION

In these preterm, low birth weight infants born in the 1980s, faster linear growth soon after term was associated with better cognition, but also with a greater risk of overweight/obesity at age 8 years and 18 years. BMI gain over the entire 18 months after term was associated with later risk of overweight/obesity, with less evidence of a benefit for IQ.