Vitamin D deficiency in pregnant women of ethnic minority: a potential contributor to preeclampsia.

OBJECTIVE: We investigated risk for comorbidities and preeclampsia at low vitamin D levels in ethnic minorities. STUDY DESIGN: Umbilical cord vitamin D (25(OH)D) concentration was determined in urban minorities: 80.9% African American and 17% Hispanic mothers-baby pairs. To identify the correlation between vitamin D levels and high-risk comorbidities which result in preeclampsia, multivariate logistic regression analyses were performed. RESULT: Below the Institute of Medicine threshold of 25(OH)D for pregnant women (25 ng ml⁻¹), obesity (P=0.055) and pregestational diabetes (odds ratio (OR)=2.056) were observed. The study median was 16 ng ml⁻¹ (<25th percentile), at which gestational hypertension (P=0.042), chronic hypertension (OR=4.842) and pregestational diabetes (OR=3.45) became relevant. The risk for preeclampsia increased 12-fold with gestational hypertension (P=0.003) and 14-fold with combined chronic and gestational hypertension (P=0.001). CONCLUSION: Pregnant women of ethnic minority had lower median vitamin D levels which may contribute to a potential risk for preeclampsia.

Effects of dexamethasone and triiodothyronine on oligohydramnios-induced pulmonary hypoplasia.

We observed for differential effects of maternal treatment with dexamethasone, triiodothyronine (T3), or both in late gestation on the growth of fetal rat lungs during oligohydramnios-induced pulmonary hypoplasia (PH). Timed-pregnant mothers were randomly selected into four treatment groups: controls (no hormone treatment); dexamethasone only; T3 only; and both dexamethasone and T3. Each underwent amniocentesis of one uterine horn on day 15 of gestation. Untouched littermate on the opposite horn served as internal control. On days 19 and 20, treated mothers were given dexamethasone (0.2 mg/kg) or T3 (7 mg/kg intramuscularly), or both and were delivered on day 21 (term) by hysterotomy. Amniocentesis resulted in PH, defined as decreased wet lung weight to body weight ratio and lung DNA contents, 83% and 90% of control, respectively (P < 0.05). Body weight and lung weight decreased with hormone treatment for both with and without amniocentesis. Although hormone treatment resulted in smaller lungs, there was no significant difference in lung weight to body weight ratio for either group with or without amniocentesis. This suggests that hormone treatment resulted in proportionate growth retardation. All hormone treatments decreased the total lung DNA content during amniocentesis (P < 0.05). Growth suppression of fetal lung associated with maternal hormone treatment is superimposed on the pulmonary hypoplasia induced by oligohydramnios.

Cardiorespiratory and stress hormone responses during first dose surfactant administration in neonates with RDS.

Our hypothesis was that surfactant instilled into the trachea, followed by body positioning maneuvers utilized to enhance drug distribution, could alter hemodynamic function and stimulate the release of catecholamines. We conducted a prospective randomized study designed to compare the immediate physiologic effects of the first dose of Exosurf Neonatal (5 mL/kg; n = 16) or Survanta (4 mL/kg; n = 18), when surfactant administration was standardized with strict adherence to drug company protocol. Physiologic variables were monitored continuously. Arterial blood gases (ABG) and plasma catecholamine concentrations were measured before, and 5 minutes after, surfactant administration. Both surfactants had an immediate effect on arterial oxygen saturation (SaO2), partial pressure of oxygen in arterial blood (PaO2), and oxygen index (OI). The improvement in oxygenation after surfactant therapy was similar in both groups. There was no significant difference in the mean umbilical arterial blood pressure (ABP) following surfactant therapy in both groups. High concentrations of plasma norepinephrine (reflecting activity of the sympathetic nerves) and epinephrine (a measure of secretion from the adrenal medulla) indicate that preterm infants with respiratory distress syndrome (RDS) prior to treatment mount a substantial stress response. The currently recommended techniques for instillation of surfactant appear not to trigger a significant further surge of plasma catecholamines or to acutely change mean ABP. Alternatively, it may be possible that the lack of response was because catecholamine release was already maximal.