Maternal serum human chorionic gonadotropin as a marker for the delivery of low-birth-weight infants in women with unexplained elevations in maternal serum alpha-fetoprotein.

We wished to ascertain whether the measurement of maternal serum human chorionic gonadotropin (MShCG) in the serum of pregnant women with unexplained elevations of maternal serum alpha-fetoprotein (MSAFP) would more precisely define those women at risk of adverse pregnancy outcomes. MShCG was measured in samples of serum obtained from women in the second trimester of pregnancy who had elevated MSAFP, normal Level II ultrasounds, and normal fetal karyotypes. Based on the characteristics of a receiver-operator curve for MShCG and birth weight, patients were divided into two groups and pregnancy outcomes were compared. Pregnant women with an unexplained elevation in MSAFP, who also had an abnormal MShCG (< or = 0.5 MoM > or = 2.5) were at significantly greater risk of delivering a low-birth-weight infant compared to women with a normal MShCG (43% and 15%, respectively; P = 0.013). They were also more likely to deliver a preterm infant (48% and 11.9%), respectively; P = 0.001). In the prediction of low birth weight, an abnormal MShCG had a sensitivity of 50%, a specificity of 81%, and a positive predictive value of 43%; in the detection of preterm delivery the values were 59%, 88%, and 48%, respectively. These findings suggest that in pregnant women with a second trimester unexplained elevation in MSAFP, abnormal MShCG levels may identify a group of women at high risk of preterm delivery or delivery of a low-birth-weight infant.

Monoamniotic and pseudomonoamniotic twins: sonographic diagnosis, detection of cord entanglement, and obstetric management.

OBJECTIVE: To assess accuracy of detecting cord entanglement in monoamniotic twins, and to describe perinatal outcomes with aggressive obstetric management. METHODS: Seven nonconjoined monoamniotic twin pregnancies and one pseudomonoamniotic twin pregnancy were diagnosed sonographically and evaluated with serial scans and cardiotocography. In the absence of other indications, patients were delivered by elective cesarean on demonstration of lung maturity at or beyond 32 weeks' gestation. RESULTS: Cord entanglement was diagnosed correctly in four pregnancies, missed in one, and excluded correctly in three. Four pregnancies were delivered after demonstration of pulmonary maturity, three because of premature rupture of membranes or uncontrollable preterm labor, and one because of fetal heart rate abnormality during tocolysis for preterm labor. The mean gestational age at delivery was 33.2 +/- 1.6 weeks, with birth weight 2011 +/- 262 g; all neonates were live-born. Newborn stays averaged 12.0 +/- 5.8 days for the eight neonates delivered electively. CONCLUSION: Monoamniotic twin pregnancies and cord entanglement in such twins were diagnosed reliably by ultrasound. Abnormal tracings prompting cesarean delivery occurred in two of the five pregnancies with cord entanglement. Amniocentesis reflected pulmonary maturity of both twins in all pregnancies so assessed, and delivery after 32 weeks' gestation, with lung maturity, resulted in good perinatal outcomes. Statistical validity of these findings is limited by our small sample size.

Transvaginal pressure pack for life-threatening pelvic hemorrhage secondary to placenta accreta.

A patient with placenta previa presented with severe vaginal bleeding. Emergency classical cesarean was followed by hysterectomy for placenta accreta. The patient's hemodynamic status continued to deteriorate and she subsequently developed a consumptive coagulopathy secondary to massive hemorrhage. A mushroom-shaped pack, created from a sterile plastic bag filled with Kerlix gauze, was placed in the pelvis and brought out through the vagina. Traction on the pack produced pressure against the pelvic floor, controlling the bleeding. This pack was prepared quickly and removed without complication in the immediate postoperative period.

Landry Guillain-Barré Strohl syndrome in pregnancy: report of three cases treated with plasmapheresis.

Landry Guillain-Barré Strohl syndrome complicating pregnancy is a rare occurrence, with only 31 cases previously reported in the obstetric literature. Cytomegalovirus as a potential etiologic agent has been documented in only two of these cases. In the past, symptomatic treatment of pregnant patients with severe and progressive symptoms has been associated with an unacceptably high rate of maternal morbidity and mortality. Recent studies have shown convincingly that plasmapheresis is the treatment of choice for nonpregnant patients acutely ill with Guillain-Barré syndrome, but data regarding its use in pregnancy are limited. We report three patients, two of whom had positive cytomegalovirus titers, in whom aggressive plasmapheresis prevented the need for ventilatory support and its inherent increase in maternal morbidity and mortality.

X-ray crystal structure of D-xylose isomerase at 4-A resolution.

The structure of D-xylose isomerase from Streptomyces rubiginosus has been determined at 4-A resolution using multiple isomorphous phasing techniques. The folding of the polypeptide chain has been established and consists of two structural domains. The larger domain consists of eight beta-strand alpha-helix (beta alpha) units arranged in a configuration similar to that found for triose phosphate isomerase, 2-keto-3-deoxy-6-phosphogluconate aldolase, and pyruvate kinase. The smaller domain forms a loop away from the larger domain but overlapping the larger domain of another subunit so that a tightly bound dimer is formed. The tetramer then consists of two such dimers. The location of the active site in the enzyme has been tentatively identified from studies using a crystal grown from a solution containing the inhibitor xylitol.