Pitfalls of the 'double bubble' sign: a case of congenital duodenal duplication

The 'double bubble' sign in prenatal diagnosis is most often associated with duodenal atresia. However, other causes of upper intestinal obstruction and cystic abdominal masses need to be considered. One possible diagnosis that can mimic the 'double bubble' sign of duodenal atresia is duodenal duplication, but little information is available to guide sonologists in the prenatal diagnosis of this rare congenital anomaly. In this case report we describe the successful prenatal diagnosis of duodenal duplication, by relying on the early gestational age of presentation, the lack of polyhydramnios, the failure to consistently demonstrate a 'double bubble' on transverse images, and the presence of a normal distal bowel pattern.

Defining the role of fluorescence in situ hybridization on uncultured amniocytes for prenatal diagnosis of aneuploidies

OBJECTIVE

This study examines the role of fluorescence in situ hybridization on uncultured amniocytes for prenatal diagnosis in a population at high risk for aneuploidies.

STUDY DESIGN

All patients undergoing amniocentesis for fetal structural abnormality on ultrasonographic examination (performed from 13 to 39 weeks), abnormal maternal serum aneuploidy screening results, or advanced maternal age with substantial parental anxiety were offered both fluorescence in situ hybridization on uncultured cells and conventional metaphase karyotyping on dividing cells.

RESULTS

From 1992 to 1995, 315 patients were studied. Mean time to obtain results was 2.8 days for fluorescence in situ hybridization and 8.3 days for karyotype. Fluorescence in situ hybridization was informative in 254 samples (80.6%), and within this group 21 aneuploidies were correctly identified. Among informative specimens there was 100% sensitivity and specificity, with 100% positive and negative predictive values. Of the 315 samples, 61 (19.4%) were uninformative or unreportable. Of 25 total cases of karyotype-proved aneuploidy, 4 were reported as uninformative by fluorescence in situ hybridization, for a total detection rate of 84%. Overall, amniocenteses performed after 24 weeks were significantly more likely to be uninformative than those performed in the second trimester (45% vs 16%, p = 0.01), peaking at a 56% uninformative rate after 33 weeks. Logistic regression analysis showed an 8% increase in the uninformative rate per week of gestational age (odds ratio 1.08, 95% confidence interval 1.04 to 1.14).

CONCLUSIONS

Fluorescence in situ hybridization on uncultured amniocytes is a rapid, clinically useful tool for prenatal diagnosis, with informative specimens being highly accurate. The combination of a structural fetal anomaly and an abnormal fluorescence in situ hybridization result should allow for definitive management decisions. The significant increase in uninformative specimens at later gestational ages limits its usefulness in the third trimester.

Drugs in pregnancy: anticonvulsants

Although 90% of patients using anticonvulsant drugs can expect a favorable pregnancy result, this outcome can be maximized by careful preconceptional, antepartum, and postpartum management. There is no clearcut agreement that any one of the four major drugs used for the treatment of seizure disorders (phenytoin, phenobarbital, valproic acid, and carbamazepine) is more teratogenic than others. Patients should be counseled that the risk of adverse maternal and neonatal outcomes from recurrent seizures during pregnancy is greater than the risk of teratogenicity with anticonvulsant drugs. The lowest possible dose of one of the four front-line agents is recommended for seizure control in pregnancy. The interaction of epilepsy and pregnancy, as well as the possible mechanisms of anticonvulsant teratogenesis, are reviewed. The use and toxicity of individual, commonly used, anticonvulsant drugs are described. Detailed consensus recommendations for preconceptional, antenatal, intrapartum, and postpartum management of patients using anticonvulsant drugs are discussed.

Prolonged labor in nulliparas: lessons from the active management of labor

OBJECTIVE

To define factors causing prolonged labor in nulliparous women undergoing active management of labor.

METHODS

We included all nulliparas delivered during 1990-1994 with spontaneous onset of labor lasting more than 12 hours, singleton gestation, cephalic presentation, and labor at greater than 37 weeks. Each patient was matched with the next nulliparous woman who delivered with a labor lasting less than 12 hours and who fulfilled the same inclusion criteria. Subjects were managed according to the previously described active management of labor protocol from The National Maternity Hospital, Dublin.

RESULTS

In the 5-year period, 9018 nulliparas met inclusion criteria, with 147 (1.6%) having prolonged labor. Prolonged labor was due to inefficient uterine action in 65%, persistent occipitoposterior position in 24%, and cephalopelvic disproportion in 11% of cases. Univariate analysis showed statistically significant (P < .05) differences in maternal body mass index, cervical dilation on admission, oxytocin use, epidural use, placement of epidural at less than 2 cm of dilation, and birth weight between these study groups. On multivariate conditional logistic regression analysis, the following were significant independent predictors for having a prolonged labor (odds ratios with 95% confidence intervals presented): 3.1 (1.3-7.3) for cervical dilation less than 2 cm on admission, 42.7 (7.5-242.0) for early epidural placement, 5.1 (1.9-13.7) for epidural placement at greater than or equal to 2 cm, and 10.2 (3.6-29.4) for birth weight greater than 4000 g.

CONCLUSION

Less-advanced cervical dilation on admission and epidural use, especially when placed early, are strongly associated with prolonged labor.

Outcome of twin gestations complicated by a single anomalous fetus

OBJECTIVE

To compare the outcome of twin gestations complicated by a single anomalous fetus with twin gestations with no fetal anomalies.

METHODS

The study included all patients with twin gestations diagnosed with a fetal anomaly in one fetus during 1990-1994, and excluded twin gestations with anomalies in both fetuses. The control twin group was composed of all other normal twin pregnancies followed and delivered at our center in the preceding 2 years.

RESULTS

We reviewed 24 twin gestations with at least one anomalous fetus. Five cases were excluded because of anomalies in both fetuses, and a further five pregnancies had selective termination or termination of the entire pregnancy. There were 14 ongoing twin pregnancies with one anomalous fetus, and their median gestational age at diagnosis was 18 weeks (range 16-20). All twin anomalies were correctly diagnosed antenatally. Gestational age at delivery and birth weight were significantly lower for twins complicated by an anomaly compared with control twins (P = .008 and P = .001, respectively). The cesarean delivery and perinatal mortality rates of twin pregnancies with anomalies were significantly higher than those of normal twins (P = .01 and P < .001, respectively).

CONCLUSION

The presence of a single anomalous fetus in a twin gestation significantly increases the risk of preterm delivery compared with nonanomalous twin gestations.