Efficacy of the genetic sonogram in a stepwise sequential protocol for down syndrome screening.

OBJECTIVES: The purpose of this study was to evaluate the efficacy of the genetic sonogram in Down syndrome screening for women who have received the stepwise sequential test. METHODS: This retrospective cohort study included women with singleton pregnancies who underwent stepwise sequential (first-trimester combined and second-trimester serum) screening and then had a genetic sonogram between March 2005 and January 2010. Stepwise sequential Down syndrome risks were multiplied by either a positive or negative likelihood ratio based on the second-trimester sonographic findings to determine the final Down syndrome risk. A final Down syndrome risk of 1:270 or higher was considered screen positive. RESULTS: A total of 6286 women fulfilled our criteria, including 17 with Down syndrome-affected fetuses. After stepwise sequential testing, the Down syndrome detection rate was 88.2% (15 of 17), and after the genetic sonogram, there was a non-significant reduction in detection to 82.4% (14 of 17; P > .05). For the 6269 unaffected pregnancies, the genetic sonogram converted 58 screen-negative results (1%) to positive and 183 screen-positive results (3.1%) to negative. The net effect was a change in the false-positive rate from 6.2% (390 of 6269) after stepwise sequential screening to 4.2% (266 of 6269) after the genetic sonogram. CONCLUSIONS: The genetic sonogram should be applied cautiously for women who have received prior prenatal screening tests. Women with screen-positive results need to be counseled that a negative sonographic result can be falsely reassuring. Conversely, for women with screen-negative results who have a risk close to the cutoff, a sonographic examination could assist in the decision of whether to accept or reject amniocentesis.

Anemia in pregnancy.

Hemodynamic changes occur in pregnancy to prepare for expected blood loss at delivery. Physiologic anemia occurs in pregnancy because plasma volume increases more quickly than red cell mass. Anemia is most commonly classified as microcytic, normocytic, or macrocytic. Iron deficiency anemia accounts for 75% of all anemias in pregnancy. Oral iron supplementation is the recommended treatment of iron deficiency anemia in pregnancy. Parenteral iron and erythropoietin can also be used in severe or refractory cases. Outcomes and treatments for other forms of inherited and acquired anemias in pregnancy vary by disease, and include nutritional supplementation, corticosteroids, supportive transfusions, and splenectomy.

Perinatal and neonatal outcomes of triplet gestations based on placental chorionicity.

The purpose of our study was to evaluate perinatal and neonatal outcomes in triplet gestations in relation to placental chorionicity. We hypothesized that triplets containing a monochorionic pair (dichorionic triamniotic) would have increased morbidity compared with triplets without a monochorionic pair (trichorionic triamniotic). We retrospectively analyzed all triplet sets > or =20 weeks delivering at our institutions from January 1995 through April 2007. Data were collected via perinatal and neonatal databases, chart review, and placental pathology. Individuals in dichorionic triamniotic triplet sets (N = 75), when compared with trichorionic triamniotic triplets (N = 309), were more likely to have a lower mean birth weight (P < 0.001) and lower gestational age at delivery (P < 0.001), spend more days in the neonatal intensive care unit (P = 0.045), have culture-proven sepsis (P = 0.02), and require intubation (P = 0.05). Multivariate analysis demonstrated that dichorionicity is not an independent cause of morbidity, but results in earlier delivery and lower birth weight. Dichorionic triamniotic triplets are at increased risk for earlier deliveries and lower birth weight at delivery compared with trichorionic triamniotic triplets.

Prenatal sonographic diagnosis of hemivertebrae: associations and outcomes.

OBJECTIVE: The purpose of this study was to evaluate associated anomalies and outcomes of fetuses with prenatally diagnosed hemivertebrae. METHODS: Fetuses with prenatally diagnosed hemivertebrae, excluding those associated with spina bifida, were identified by searching the prospectively maintained ultrasound databases of 4 institutions from 1997 to August 2007. Associated birth defects were tabulated by organ system and hemivertebra location. Outcomes included karyotypes, gestational ages, and routes and outcomes of deliveries. RESULTS: Nineteen fetuses had a diagnosis of hemivertebrae at a mean gestational age +/- SD of 20.5 +/- 5.4 weeks. Fourteen (73.7%) fetuses had additional anomalies, of which 5 (35.7%) were syndromic (4 with cloacal exstrophy and omphaloceles and 1 with Jarcho-Levin syndrome). Karyotypes were normal in all 11 available cases, each of which had additional anomalies. Fourteen (73.7%) neonates were live born at a mean gestational age of 34.9 +/- 4.3 weeks, of which 7 (50%) were born by cesarean delivery. Ten neonates (71.4%) were delivered before term, and 4 (28.6%) were growth restricted (<10th percentile). Two (14.3%) of these neonates died; both had cloacal exstrophy and large omphaloceles. The remaining pregnancies were terminated (4 [21.1%]) or had a fetal death (1 [5.3%]). CONCLUSIONS: Most fetuses with prenatally diagnosed hemivertebrae have additional anomalies, often syndromic, which affect the prognosis. Affected pregnancies have high rates of cesarean delivery and growth restriction. Neonates with nonisolated hemivertebrae are more often delivered before term and have higher mortality rates.

Prothrombotic risk factors in infants of diabetic mothers.

BACKGROUND: Infants of diabetic mothers (IDMs) are at an increased risk for thromboembolic disease. The mechanism(s) to explain this association is unclear. We hypothesized that the pathophysiology of thrombosis in IDMs is multifactorial and likely involves interactions among genetic and acquired factors affecting the procoagulant, anticoagulant and fibrinolytic pathways. OBJECTIVE: To compare the prevalence of common prothrombotic risk factors in a cohort of IDMs to a matched control group. PATIENTS/METHODS: Full-term infants born to mothers with diet controlled (A1-IDM) (N=17), insulin requiring diabetes (ID-IDM) (N=20) and healthy term infants (controls) (N=20) matched for mode of delivery had cord blood collected at delivery. Samples were analyzed for the following: factor V Leiden (FVL), prothrombin 20210A (P20210A), methylenetetrahydrofolate reductase C677 T (MTHFR), Factor VIII (FVIII), Protein C (PC), Lipoprotein(a) (Lp(a)) and plasminogen activator inhibitor-1 (PAI-1). RESULTS: None of the infants had a clinically apparent thrombotic event. IDM mothers and their infants were clinically similar to controls except for a higher prevalence of hypoglycemia (30 vs 0%; p=0.005). There was no significant difference in the prevalence of the common genetic risk factors (FVL, P20210A, MTHFR) FVIII, or PAI-1 levels. Elevated Lp(a) levels were seen more frequently in IDMs than Controls (40 vs 20%) but this difference was not statistically significant. The PC activity (%) was significantly decreased in the IDM group compared to controls, 35+/-12 vs 44+/-9 (p<0.005). A1-IDM had lower PC activity compared to ID-IDM (p=0.05) and controls (p=0.001). CONCLUSIONS: PC deficiency is likely one mechanism to explain thrombosis in IDMs.

The use of lamellar body counts to predict fetal lung maturity in pregnancies complicated by diabetes mellitus.

OBJECTIVE: The purpose of this study was (1) to correlate amniotic fluid lamellar body counts with the lecithin/sphingomyelin ratio and the presence of phosphatidylglycerol in pregnancies that were complicated by maternal diabetes mellitus and (2) to determine a lamellar body count value that maximizes sensitivity and specificity in the prediction of fetal lung maturity. STUDY DESIGN: We reviewed our prospectively collected perinatal database from November 1992 through October 1999 to identify pregnancies that were complicated by diabetes mellitus for which fetal lung maturity studies had been performed within 72 hours of delivery. Lamellar body counts were correlated with lecithin-sphingomyelin ratio and phosphatidylglycerol values. The sensitivities and specificities of various lamellar body count cutoff values were calculated with the lecithin/sphingomyelin ratio and phosphatidylglycerol values as indicators of fetal lung maturity. Receiver operating curves were used to determine the lamellar body count that indicated fetal lung maturity. Our neonatal database was reviewed for this same time period to obtain all cases of respiratory distress syndrome. The maternal data were compared with the neonatal data to determine whether distress syndrome had developed in an infant who had undergone fetal lung maturity testing respiratory. RESULTS: Lamellar body counts were correlated with lecithin/sphingomyelin ratio (r = 0.51, P <.001) and phosphatidylglycerol values (r = 0.57, P <.001) in 90 diabetic pregnant patients. A lamellar body count of 37,000/microL was found to have a sensitivity of 80% and a specificity of 100% in the prediction of fetal lung maturity by standardized methods of phospholipid analysis. There were no cases of neonatal respiratory distress syndrome in this study population. CONCLUSION: The lamellar body count is a valid, rapid screening test for the determination of biochemical fetal lung maturity in pregnancies that are complicated by diabetes mellitus. A lamellar body count of > or =37,000/microL correlated with the lecithin/sphingomyelin ratio and phosphatidylglycerol values in the pregnancies of diabetic patients. Use of lamellar body counts in pregnancies that are complicated by diabetes mellitus could decrease the need for time-consuming and more costly phospholipid profiles. A full phospholipid profile is recommended for amniotic fluid specimens with lamellar body count values of <37,000/microL.

Contribution of elective delivery to severe respiratory distress at term.

We sought to determine the contribution of elective delivery to severe respiratory distress syndrome (RDS) on a weekly basis from 37-40 weeks' gestation. Chart reviews confirmed gestational age, delivery reason, and primary diagnosis of all inborn neonates with RDS requiring mechanical ventilation delivered at 37 0/7-40 6/7 weeks' gestation from 1/1/90-12/31/99. Exclusion criteria were sepsis, pneumonia, meconium aspiration, asphyxia, pulmonary hemorrhage, hydrops, chromosomal abnormality, or congenital malformations affecting respiration. Thirty-five thousand and thirty-one deliveries occurred from 37 0/7-40 6/7 weeks; 18 (0.05%) had RDS requiring mechanical ventilation. Nine infants delivered at 37 0/7-37 6/7 weeks, (OR for RDS = 38.5; 95% CI = 8.3, 178.3), seven delivered at 38 0/7-38 6/7 weeks, (OR for RDS = 13.3; 95% CI = 2.8, 64.0), and two delivered at 39 0/7-40 6/7 weeks. Six of 18 infants were electively delivered without documented lung maturity. Infants born at 37 0/7-38 6/7 weeks are at significantly increased risk for severe RDS. One third of RDS cases were potentially avoidable.