Invasive fetal testing is indicated for pregnancies at elevated risk of genetic abnormalities; however, the optimal testing strategy is unknown. SMFM recommends chromosomal microarray (CMA) in cases where fetal anomalies are identified. Otherwise, the choice between CMA and karyotype is unclear. The option of a rapidly resulting test such as FISH is omitted from guidelines. We hypothesize that a FISH-based reflex testing strategy with FISH followed by karyotype for abnormal FISH results and CMA for normal FISH results will yield shorter time to results and lower cost to the patient and health system. We conducted a retrospective cohort analysis from a single health system over 2 years to compare the result wait time and determine cost per patient for different testing strategies. Two strategies were used during this interval: a guideline-based strategy with the option of FISH based on clinical scenario and a FISH-based reflex strategy. Actionable results were defined as either an abnormal FISH result or CMA/karyotype result if normal FISH. Diagnostic results were defined as the final diagnostic test result. Descriptive statistics were used to compare demographic characteristics between the two strategies. Outcomes were compared using the t-test. Cost analysis was performed using 2018 costs as billed to insurers. Eighty-six patients were included in this study with 36 in the reflex strategy and 50 in the guideline strategy. Demographic characteristics between testing strategies were similar, including maternal age and indication for testing. Actionable results were reported sooner for the reflex-based strategy (9.5 ± 8.5 vs 10.5 ± 4.9 days, p = 0.48). Diagnostic results were reported sooner for the guideline-based strategy (10.7 ± 4.9 vs 12.4 ± 6.7 days, p = 0.21). Additionally, the costs per patient were significantly less for the guideline-based strategy ($1637 vs $2134, p = 0.02). A prenatal diagnostic testing strategy based on SMFM guidelines is associated with lower costs. The time to actionable and diagnostic results was similar between a guideline-based and reflex-based strategy; however, the shorter actionable result time noted in a reflex-based strategy may be clinically significant if testing is performed in time-sensitive scenarios. These results advocate for inclusion of recommendations regarding FISH testing in future SMFM guidelines.

OBJECTIVE:We examined the effects of magnesium sulfate on non-neurologic neonatal outcomes with respect to cord blood magnesium level. STUDY DESIGN:We conducted a secondary analysis of the Maternal-Fetal Medicine Units Beneficial Effects of Antenatal Magnesium (MFMU BEAM) trial comparing the upper and lower quintiles of cord blood magnesium level. Outcomes included cerebral palsy (CP), necrotizing enterocolitis (NEC), retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), and assessments of mental and motor disability. Logistic regression was used to estimate adjusted odds ratios (aORs) of each outcome, controlling for gestational age (GA), birth weight, and treatment group (TG). RESULTS:A total of 1,254 women of the 2,444 included in the BEAM trial had cord blood magnesium levels recorded. GA and birth weight were lower and TG was more common in the upper quintile cohort (p < 0.001). Neonates in the upper quintile were more likely to have severe NEC (OR, 2.41, 95% confidence interval [CI]: 1.11-5.24), ROP (OR, 1.65, 95% CI: 1.05-2.59), and BPD (OR, 1.70, 95% CI: 1.04-2.73). Adjustment for covariates demonstrated no difference in the NEC, ROP, and BPD rates, although there was a decrease in rates of mental disability index < 70 which was not seen in the unadjusted analysis (aOR, 0.49, 95% CI: 0.25-0.99). CONCLUSION:Higher cord blood magnesium levels do not appear to have adverse non-neurologic effects on the neonate and may demonstrate improvement in neurologic outcomes.

Purpose: We examined the effects of magnesium on premature neonatal outcomes complicated by chorioamnionitis.Materials and methods: We conducted a secondary analysis of data from the BEAM Trial, an RCT to determine if antenatal magnesium decreases the incidence of CP in preterm birth. We compared the effect of magnesium sulfate by the presence or absence of chorioamnionitis. Outcomes examined include CP, IVH, NEC, BPD, and assessments of mental and motor disability. Logistic regression was used to estimate adjusted odds ratios of each outcome.Results: About 1944 women were included in this analysis of which 228 were diagnosed with chorioamnionitis. Demographic characteristics were similar between women randomized to receive magnesium or placebo. Magnesium therapy demonstrated no significant reduction in CP in the presence of chorioamnionitis (OR 0.76, CI: 0.19-2.76) but does demonstrate benefit in the absence of chorioamnionitis (OR 0.52, CI: 0.31-0.86).Conclusions: Antenatal magnesium did not show a clear neuroprotective effect in the setting of chorioamnionitis.

The Effects of Cigarette Smoking and Gestational Weight Change on Birth Outcomes in Obese and Normal-Weight Women. Wendy L. Hellerstedt, John H. Himes, Mary Story, Irene R. Alton, Laura E. Edwards. American Journal of Public Health 1997;87:591-6. Objectives. The associations of infant birth outcomes with maternal pregravid obesity, gestational weight gain, and prenatal cigarette smoking were examined. Methods. A retrospective analysis of 1343 obese and normal-weight gravidas evaluated the associations of cigarette smoking, gestational weight change, and pregravid body mass index with birthweight, low birthweight, and smalland large-for-gestational-age births. Results. Smoking was associated with the delivery of lower-birthweight infants for both obese and normal-weight women, and gestational weight gain did not eliminate the birthweight-lowering effects of smoking. Women at highest risk of delivering lower-birthweight infants were obese smokers whose gestational gains were less than 7 kg and normal-weight smokers whose gestational gains were less than 11.5 kg. Conclusions. To balance the risks of small and large-size infants, gains of 7 to 11.5 kg for obese women and 11.5 to 16 kg for normal-weight women appear appropriate.