Antenatal magnesium sulfate and the need for mechanical ventilation in the first three days of life.

BACKGROUND: Antenatal administration of magnesium sulfate (MgSO4) to women in preterm labor has gained widespread use. This study examined the relationship between MgSO4 exposure with neonatal respiratory outcomes. METHODS: Very low birth weight (VLBW) infants exposed to antenatal MgSO4 were included. Infants who were intubated anytime during the first three days of life were compared to those who were not intubated regarding their demographic and clinical characteristics, MgSO4 therapy, immediate respiratory outcomes, and occurrence of intraventricular hemorrhage (IVH) using student t-test, chi square testing and logistic regression analysis to control for confounding variables. Correlation coefficient of MgSO4 cumulative dose given and duration of infusion with delivery room resuscitation and need for mechanical ventilation in the first 3 days of life were also calculated. Multilinear regression analysis was used to control for confounding factors. RESULTS: Intubated group included 96 infants while non-intubated group included 171 infants. Although, intubated group has younger gestational age (26 vs. 29 weeks, p < 0.01) and lower birth weight (786 vs. 1115 g (g), p < 0.01), there were no significant differences between groups in regard to MgSO4 cumulative dose (24 vs. 27 g, p = 0.29), infusion time (14.6 vs. 18 h, p = 0.19) or infants' serum magnesium level (2.6 vs. 2.8 milliequivalents (mEq)/L p = 0.86). There was no correlation between cumulative MgSO4 dose with endotracheal intubation or cardiac resuscitation in the delivery room (cc: -0.03, p = 0.66; and 0.02, p = 0.79, respectively) or the need for mechanical ventilation in the first 3 days of life (cc: -0.04 to -0.07, p = 0.21-0.51). In addition, there was no relationship between MgSO4 dose, duration of infusion, or infant's serum magnesium level and occurrence of IVH. CONCLUSION: Regardless of dose or duration of infusion, antenatal MgSO4 exposure is not associated with increased intubation or mechanical ventilation early in life.

Unequal burden of Zika-associated microcephaly among populations with public and private healthcare in Salvador, Brazil.

OBJECTIVES: To describe the differences in clinical presentation and relative disease burden of congenital Zika syndrome (CZS)-associated microcephaly at 2 large hospitals in Salvador, Brazil that serve patients of different socioeconomic status (SES). METHODS: Clinical and serologic data were collected prospectively from pregnant women and their infants, who delivered at 2 study centers during the 2015-2016 Zika virus (ZIKV) epidemic in Salvador, Brazil. RESULTS: Pregnant women from Salvador, Brazil delivering in a low SES hospital had 3 times higher ZIKV exposure rate than women at a high SES hospital. However, different SES hospitals had similar prevalence of infants with CZS-associated microcephaly (10% vs 6%, p = 0.16) after controlling for ZIKV exposure in their mothers. CONCLUSIONS: Our study supports the positive association between low SES, high maternal ZIKV exposure, and high rates of CZS-associated microcephaly.

Social determinants associated with Zika virus infection in pregnant women.

This study aims to describe the sociodemographic determinants associated with exposure to Zika Virus (ZIKV) in pregnant women during the 2015-2016 epidemic in Salvador, Brazil. METHODS: We recruited women who gave birth between October 2015 and January 2016 to a cross-sectional study at a referral maternity hospital in Salvador, Brazil. We collected information on their demographic, socioeconomic, and clinical characteristics, and evaluated their ZIKV exposure using a plaque reduction neutralization test. Logistic regression was then used to assess the relationship between these social determinants and ZIKV exposure status. RESULTS: We included 469 pregnant women, of whom 61% had a positive ZIKV result. Multivariate analysis found that lower education (adjusted Prevalence Rate [aPR] 1.21; 95%CI 1.04-1.35) and food insecurity (aPR 1.17; 95%CI 1.01-1.30) were positively associated with ZIKV exposure. Additionally, age was negatively associated with the infection risk (aPR 0.99; 95%CI 0.97-0.998). CONCLUSION: Eve after controlling for age, differences in key social determinants, as education and food security, were associated with the risk of ZIKV infection among pregnant women in Brazil. Our findings elucidate risk factors that can be targeted by future interventions to reduce the impact of ZIKV infection in this vulnerable population.

Risk of Zika microcephaly correlates with features of maternal antibodies.

Zika virus (ZIKV) infection during pregnancy causes congenital abnormalities, including microcephaly. However, rates vary widely, and the contributing risk factors remain unclear. We examined the serum antibody response to ZIKV and other flaviviruses in Brazilian women giving birth during the 2015-2016 outbreak. Infected pregnancies with intermediate or higher ZIKV antibody enhancement titers were at increased risk to give birth to microcephalic infants compared with those with lower titers (P < 0.0001). Similarly, analysis of ZIKV-infected pregnant macaques revealed that fetal brain damage was more frequent in mothers with higher enhancement titers. Thus, features of the maternal antibodies are associated with and may contribute to the genesis of ZIKV-associated microcephaly.