Early Elevation in Interleukin-6 is Associated with Reduced Growth in Extremely Low Birth Weight Infants

Association of maternal migrant background with inflammation during pregnancy - Results of a birth cohort study in Germany

BACKGROUND

Health disparities in children of immigrants are prevalent from birth and are hypothesized to - in part - emerge as a biological consequence of migration's unfavorable social and psychological sequelae. The aim of this study was to examine whether maternal migrant background is associated with inflammation during pregnancy - a key pathway by which maternal states and conditions during pregnancy may influence fetal development and subsequent pregnancy, birth, and child developmental and health outcomes.

MATERIAL AND METHODS

Data was available from 126 pregnant women who participated in a population based multi-site prospective birth cohort study in Bielefeld and Berlin, Germany. The study included two study visits in mid- and late pregnancy. At each visit, a composite maternal pro-inflammatory score was derived from circulating levels of plasma inflammatory markers (IL-6, CRP). Migrant background was defined by country of origin of participants and their parents' (Turkey or other) and generation status (1st or 2nd generation). We applied hierarchical linear models (HLM) in order to quantify the relationship between different migrant background variables and inflammation during pregnancy after adjustment for potential confounders (including socioeconomic status).

RESULTS

Migrant background was significantly associated with inflammation during pregnancy. When compared to women without migrant background, levels of inflammation were increased in 1) pregnant women with migrant background in general (B = 0.35, SE = 0.12, p < .01); 2) 1st (B = 0.28, SE = 0.15, p < .10) and 2nd generation (B = 0.40, SE = 0.15, p < .01); 3) women with a Turkish migrant background (B = 0.28, SE = 0.14, p < .10) and women with another migrant background (B = 0.42, SE = 0.15, p < .01); and 4) 2nd generation Turkish origin women (B = 0.38, SE = 0.20, p < .10), 1st generation women with other migrant background (B = 0.44, SE = 0.26, p < .10), and 2nd generation women with other migrant background (B = 0.43, SE = 0.17, p < .05).

DISCUSSION

Our findings support a role for maternal inflammation as a pathway of intergenerational transmission of migration-related health inequalities, suggest that the effect seems to persist in 2nd generation immigrants, and highlight the need for future research and targeted interventions in this context.

IL-6 Predicts Poor Early Post-Natal Growth in Very Low-Birth-Weight Infants in a Low-Middle Income Setting

BACKGROUND

Extra-uterine growth restriction (EUGR) is common in preterms and may be associated with elevated pro-inflammatory cytokines.

OBJECTIVE

Describe postnatal growth in a cohort of very low-birth-weight (VLBW) infants and determine the association of interleukin-6 (IL-6) and tumour necrosis factor alpha (TNF-α) in umbilical cord blood with growth at 40 weeks and 12 months postmenstrual age (PMA).

METHODS

Single-centre, prospective cohort study conducted from 1 June 2017 to 31 January 2019 with follow-up to 31 March 2020. Infants <1500 g at birth were enrolled, cord blood collected for IL-6 and TNF-α assays and postnatal care, including anthropometry, provided to 12 months PMA. Informed consent and ethics approval were obtained.

RESULTS

In total, 279 patients were enrolled; 84 (30.1%) died before 12 months and 91 (32.6%) lost to follow-up. Anthropometry was available for 151 infants at 40 weeks and 105 at 12 months. Z-Scores at 40 weeks for males and females combined were -2.5, -2.1 and -1.2 for weight, length and head circumference. EUGR occurred in 103/113 (91.2%), 98/107 (91.6%) and 70/109 (64.2%) participants for weight, length and head circumference. Elevated IL-6 was associated with restricted weight (56.0 vs. 14.5 pg/ml, p = 0.02) and length (60.4 vs. 7.3 pg/ml, p = 0.01) at 40 weeks. There was no difference in IL-6 at 12 months and no difference in TNF-α at 40 weeks or 12 months.

CONCLUSION

The study reports significant EUGR. Elevated IL-6 was associated with growth restriction at 40 weeks but not 12 months PMA.

Body composition and neuromotor development in the year after NICU discharge in premature infants

BACKGROUND

Hypothesis: neuromotor development correlates to body composition over the first year of life in prematurely born infants and can be influenced by enhancing motor activity.

METHODS

Forty-six female and 53 male infants [27 ± 1.8 (sd) weeks] randomized to comparison or exercise group (caregiver provided 15-20 min daily of developmentally appropriate motor activities) completed the year-long study. Body composition [lean body and fat mass (LBM, FM)], growth/inflammation predictive biomarkers, and Alberta Infant Motor Scale (AIMS) were assessed.

RESULTS

AIMS at 1 year correlated with LBM (r = 0.32, p < 0.001) in the whole cohort. However, there was no effect of the intervention. LBM increased by ~3685 g (p < 0.001)); insulin-like growth factor-1 (IGF-1) was correlated with LBM (r = 0.36, p = 0.002). IL-1RA (an inflammatory biomarker) decreased (-75%, p < 0.0125). LBM and bone mineral density were significantly lower and IGF-1 higher in the females at 1 year.

CONCLUSIONS

We found an association between neuromotor development and LBM suggesting that motor activity may influence LBM. Our particular intervention was ineffective. Whether activities provided largely by caregivers to enhance motor activity in prematurely born infants can affect the interrelated (1) balance of growth and inflammation mediators, (2) neuromotor development, (3) sexual dimorphism, and/or (4) body composition early in life remains unknown.

A Randomized Trial of Maternal Docosahexaenoic Acid Supplementation to Reduce Inflammation in Extremely Preterm Infants

Maternal supplementation with 1000 mg/day docosahexaenoic acid (DHA) provides third trimester DHA accretion levels in breast milk for the preterm infant. We hypothesized that DHA supplementation to mothers providing breastmilk for extremely preterm infants would result in decreased inflammatory markers, in the infant. Mother/infant dyads (n = 27) were enrolled at birth and mothers were assigned to receive 200 or 1000 mg/day of DHA. Milk and plasma samples were analyzed for fatty acids and inflammatory markers. Decreases in inflammation were observed in both maternal and infant plasma and correlated with red blood cell (RBC) DHA levels. The fact that maternal DHA supplementation decreases infant markers of inflammation implies that DHA, delivered through breastmilk, has the potential to decrease inflammation in the infant.

Acculturation and interleukin (IL)-6 concentrations across pregnancy among Mexican-American women

BACKGROUND

The process of acculturation (post-migration acquisition of host culture and/or loss of heritage culture) likely represents a key mediator of the observed post-migration decline in health that is evident among immigrant populations such as Mexican Americans. The observations that migrant health declines progressively as not only a function of length of stay in the U.S. but also across generations, and that this inter-generational decline in health is evident as early as at the time of birth itself, supports the concept of fetal programming of acculturation's effects. However, the underlying mechanisms remain to be elucidated. Inflammation during pregnancy represents a candidate pathway of particular interest for 2 reasons: it represents a key biological mediator of the psychosocial and/or behavioral sequelae of acculturation on health, and it represents a key pathway by which maternal states and conditions during pregnancy may influence fetal development and subsequent birth and child developmental and health outcomes. Therefore, the aim of this study was to examine the relationship between acculturation and inflammation across pregnancy in a population of Mexican-American women. Specifically, we tested the hypothesis that a higher level of acculturation is associated with higher circulating concentrations across pregnancy of the pro-inflammatory cytokine interleukin-6 (IL-6).

METHODS

75 pregnant first- or second-generation Mexican-American women constituted the study population. Acculturation was quantified using a commonly-used and previously validated measure - the Acculturation Rating Scale for Mexican Americans (ARSMA). Maternal blood samples were collected during early, mid and late pregnancy for analysis of circulating IL-6 concentrations.

RESULTS

Hierarchical linear models indicated a significantly and positive main effect of acculturation on IL-6 concentrations across pregnancy after adjusting for key covariates including gestational age(s) at blood sampling, socioeconomic status, pre-pregnancy BMI, and presence of obstetric risk conditions.

CONCLUSIONS

Maternal inflammation during pregnancy may represent a biological pathway of interest in the context of the inter-generational effects of acculturation from a mother to her as-yet-unborn child.