Effects of advanced maternal age and race/ethnicity on placental weight and placental weight/birthweight ratio in very low birthweight infants.

To study the association of advanced maternal age (AMA) and race/ethnicity on placental pathology in very low birthweight (VLBW) infants. Retrospective analysis of placental pathology of inborn singleton VLBW infants from a regional level 3 NICU between July, 2002 and June, 2009. Subjects were stratified by age and race/ethnicity. Statistical analysis included One-way ANOVA, Chi Square and multivariable analyses. A total of 739 mother/infant dyads were included. AMA was associated with a decrease in placental weight and placental weight/birthweight ratio. Black/Non-Hispanic mothers ≥35 had a lower placental weight (p = 0.01) and lower placental weight/birth weight ratio (z-score, -0.45 ± 0.71 vs -0.04 ± 1.1, p = 0.01) compared to Black/Non-Hispanic mothers <35 years of age. After controlling for gestational age, race/ethnicity, maternal diabetes, maternal smoking, maternal hypertension and clinical chorioamnionitis, AMA, but not race/ethnicity, remained independently associated with placental weight/birthweight ratio z score (full model r(2) = 0.22, p < 0.01). In our study sample of VLBW infants, placental weight and placental weight/birthweight ratio were lower in mothers of advanced maternal age compared to mothers <35 years of age. Our data suggest that maternal age affects placentation in VLBW infants, which could influence maternal and neonatal outcomes.

Effects of pre-pregnancy obesity, race/ethnicity and prematurity.

To investigate the association between maternal pre-pregnancy obesity, race/ethnicity and prematurity. Retrospective cohort study of maternal deliveries at a single regional center from 2009 to 2010 time period (n = 11,711). Generalized linear models were used for the analysis to estimate an adjusted odds ratio with 95% confidence interval of the association between maternal pre-pregnancy obesity, race/ethnicity and prematurity. Analysis controlled for diabetes, chronic hypertension, previous preterm birth, smoking and insurance status. The demographics of the study population were as follows, race/ethnicity had predominance in the White/Non-Hispanic population with 60.1%, followed by the Black/Non-Hispanic population 24.2%, the Hispanic population with 10.3% and the Asian population with 5.4%. Maternal pre-pregnancy weight showed that the population with a normal body mass index (BMI) was 49.4%, followed by the population being overweight with 26.2%, and last, the population which was obese with 24.4%. Maternal obesity increased the odds of prematurity in the White/Non-Hispanic, Hispanic and Asian population (aOR 1.40, CI 1.12-1.75; aOR 2.20, CI 1.23-3.95; aOR 3.07, CI 1.16-8.13, respectively). Although the Black/Non-Hispanic population prematurity rate remains higher than the other race/ethnicity populations, the Black/Non-Hispanic population did not have an increased odds of prematurity in obese mothers (OR 0.87; CI 0.68-1.19). Unlike White/Non-Hispanic, Asian and Hispanic mothers, normal pre-pregnancy BMI in Black/Non-Hispanic mothers was not associated with lower odds for prematurity. The odds for mothers of the White/Non-Hispanic, Hispanic and Asian populations, for delivering a premature infant, were significantly increased when obese. Analysis controlled for chronic hypertension, diabetes, insurance status, prior preterm birth and smoking. Obesity is a risk factor for prematurity in the White/Non-Hispanic, Asian and Hispanic population, but not for the Black/Non-Hispanic population. The design and evaluation of weight-based maternal health programs that aggregate race/ethnicity may not be sufficient. The optimal method to address maternal pre-pregnancy and intra-pregnancy weight-related health disorders may need to be stratified along race/ethnicity adjusted strategies and goals. However, a more global preventative strategy that encompasses the social determinants of health may be needed to reduce the higher rates of prematurity among the Black/Non-Hispanic population.

Work of breathing indices in infants with respiratory insufficiency receiving high-flow nasal cannula and nasal continuous positive airway pressure.

OBJECTIVE: To compare work of breathing (WOB) indices between two nCPAP settings and two levels of HFNC in a crossover study. STUDY DESIGN: Infants with a CGA 28-40 weeks, baseline of HFNC 3-5 lpm or nCPAP 5-6 cmH2O and fraction of inspired oxygen ≤40% were eligible. WOB was analyzed using respiratory inductive plethysmography (RIP) for each of the four modalities: HFNC 3 and 5 lpm, nCPAP 5 and 6 cmH2O. N=20; Study weight 1516 g (±40 g). RESULT: Approximately 12,000 breaths were analyzed indicating a high degree of asynchronous breathing and elevated WOB indices at all four levels of support. Phase angle values (means) (P<0.01): HFNC 3 lpm (114.7°), HFNC 5 lpm (96.7°), nCPAP 5 cmH2O (87.2°), nCPAP 6 cmH2O (80.5°). The mean phase relation of total breath (PhRTB) (means) (P<0.01): HFNC 3 lpm (63.2%), HFNC 5 lpm (55.3%), nCPAP 5 cmH2O (49.3%), nCPAP 6 cmH2O (48.0%). The relative labored breathing index (LBI) (means) (P≤0.001): HFNC 3 lpm (1.39), HFNC 5 lpm (1.31), nCPAP 5 cmH2O (1.29), nCPAP 6 cmH2O (1.26). Eighty-two percent of the study subjects-respiratory mode combinations displayed clustering, in which a proportion of breaths either occurred predominantly out-of-phase (relative asynchrony) or in-phase (relative synchrony). CONCLUSION: In this study, WOB indices were statistically different, yet clinically similar in that they were elevated with respect to normal values. These infants with mild-to-moderate respiratory insufficiency demonstrate a meaningful elevation in WOB indices and continue to require non-invasive respiratory support. Patient variability exists with regard to biphasic clustered breathing patterns and the level of supplemental fraction of inspired oxygen ≤40% alone does not provide guidance to the optimal matching of WOB indices and non-invasive respiratory support.