Outcomes of pregnancies with more than one positive prenatal screening result in the first or second trimester.

OBJECTIVE: To describe adverse outcomes and fetal abnormalities in women with a positive prenatal screening result for more than one disorder. STUDY DESIGN: Study participants were drawn from a population of 452 901 women pregnant with singletons entering the California Prenatal Screening Program in their first-trimester. Risk assessment was provided for trisomy 21 and trisomy 18 in the first-trimester and trisomy 21, trisomy 18, neural tube defects, and Smith-Lemli-Opitz syndrome in the second-trimester. Inclusion in this study required positive screening for more than one of the screened conditions and a completed outcome of pregnancy survey. RESULTS: A total of 874 women met our study inclusion criteria. Over 25% of these pregnancies had a fetus with a chromosomal abnormality. Of the euploid pregnancies, 6.9% had a fetus with a major birth defect. Of the pregnancies with a fetus with neither a chromosomal abnormality nor a major birth defect, 9.3% ended in fetal demise. Overall, more than 50% of women with multiple positive screening results had either a fetus with a birth defect or a poor pregnancy outcome. CONCLUSION: Although it is rare to screen positive for more than one condition, such results indicate a very high risk for chromosomal abnormality, fetal demise, or structural abnormality.

Congenital malformations in pregnancies complicated by NIDDM.

OBJECTIVE: To determine whether the use of oral hypoglycemic agents during early pregnancy is associated with a risk of congenital malformations in infants of mothers with non-insulin-dependent diabetes mellitus (NIDDM) independent of maternal metabolic control. RESEARCH DESIGN AND METHODS: From a prospectively collected data-base of pregnancies complicated by diabetes at a large urban medical center, we identified 332 consecutive infants born to women with NIDDM who did not participate in a preconceptional diabetes care program. Stepwise logistical regression was used to identify maternal characteristics that were independently associated with risks of major and minor congenital malformations in infants. RESULTS: Overall, 56 (16.9%) of the 332 infants were born with congenital anomalies (11.7% major anomalies and 5.1% minor anomalies). Analysis of data from subgroups of women who were treated with diet therapy, exogenous insulin, or sulfonylurea compounds during the first 8 weeks of gestation did not reveal statistically significant differences in major or minor malformation rates among the three groups. Stepwise logistic regression analysis revealed two maternal characteristics that were independently associated with major malformations in infants: maternal HbA1c at initial presentation for care (direct relationship; P = 0.0007) and the maternal age at onset of diabetes (inverse relationship; P = 0.009). The risk of major malformations was unrelated to the mode of antidiabetic therapy during early pregnancy. No relationship was found between maternal glycemia or treatment modality and rates of minor congenital anomalies. CONCLUSIONS: These data indicate that, in the absence of special preconceptional care, NIDDM is associated with a risk for major congenital anomalies that is in the range reported for pregnancies complicated by insulin-dependent diabetes mellitus. Moreover, the risk in individual patients appears to be related to maternal glycemic control rather than to the mode of antidiabetic therapy during early pregnancy.

Electrooptic modulation up to 40 GHz in a barium titanate thin film waveguide modulator.

The high frequency operation of a low-voltage electrooptic modulator based on a strip-loaded BaTiO3 thin film waveguide structure has been demonstrated. The epitaxial BaTiO3 thin film on an MgO substrate forms a composite structure with a low effective dielectric constant of 20.8 at 40 GHz. A 3.9 V half-wave voltage with a 3.7 GHz 3-dB bandwidth and a 150 pm/V effective electrooptic coefficient is obtained for the 3.2mm-long modulator at 1.55 ?m. Broadband modulation up to 40 GHz is measured with a calibrated detection system. Numerical simulations indicate that the BaTiO3 thin film modulator has the potential for a 3-dB operational bandwidth in excess of 40 GHz through optimized design.

Cervical length measurements in pregnancy are longer when measured with three-dimensional transvaginal ultrasound.

OBJECTIVE: To compare cervical length measurements obtained by transvaginal two-dimensional (2D) and transvaginal three-dimensional (3D) ultrasound. STUDY DESIGN: Thirty-four consecutive women having transvaginal assessment of cervical length as part of an obstetric ultrasound examination consented to have a 3D ultrasound scan. The cervical lengths obtained by the two methods were compared by Student's t test and regression equations. RESULTS: The mean cervical 2D length was 35.7 +/- 1.4 (SE) mm and 3D length was 43.7 +/- 1.9 mm (difference 8.0 mm +/- 0.98, p < 0.001). In the 12 women with cervical length on 2D < 35 mm, there was a 7.5 +/- 1.7 (SE) mm difference (p = 0.007). In all but one woman the 3D length obtained was the same or longer than the 2D length. The longer the cervical length on 3D imaging, the greater the difference from the 2D length (p < 0.001). CONCLUSION: The longer 3D cervical measurements may reflect the inability to measure the cervix adequately with 2D imaging, owing to anatomical factors. This finding may be useful in improving the predictive value of transvaginal ultrasound in assessing the risk for preterm delivery.

BaTiO3 thin-film waveguide modulator with a low voltage-length product at near-infrared wavelengths of 0.98 and 1.55 microm.

A BaTiO3 thin-film electro-optic waveguide modulator with a low half-wave voltage-length product has been demonstrated at near-infrared wavelengths of 1-1.6 microm. Half-wave voltage-length products as small as 0.25 and 0.5 V cm were measured for a 5-mm-long device at wavelengths of 973 and 1561 nm, respectively. The effective electro-optic coefficients were calculated as 420 pm/V at 973 nm and 360 pm/V at 1561 nm. Further improvements in device performance by optimizing the ferroelectric domain structure are anticipated.

A novel method of focus sensing for the laser scanner microscope.

An unconventional approach to the focus-sensing problem in a high-speed cell scanner has resulted in a method of directly detecting the position of the cell layer. This is done by using two coaxial but axially shifted beams, one focused on either side of the cell layer. The modulation induced in each beam by the cell's fine structure is compared electronically to yield the focus-error signal. The beams are orthogonally polarized, therefore separable, and are independently detected. The two detector-output signals are used to form both the focus-error signal and the scanner's primary data signal. This focus-sensing technique has been analytically modeled and experimentally demonstrated for a high-numerical-aperture system. In that system, the depth of focus is less than the thickness of the cell layer. It is shown that a lens fabricated from a birefringent crystal is an attractive means of forming the required orthogonally polarized axially shifted beams.

Prenatal ultrasound findings in a fetus with paternal uniparental disomy 14q12-qter.

We present the prenatal ultrasound findings in a case of postnatally identified paternal uniparental isodisomy 14q12-qter. Increased nuchal translucency and a large omphalocele were identified at 14 weeks' gestation. Karyotyping revealed a normal male, 46,XY. As gestation advanced, polyhydramnios developed, skeletal abnormalities involving the long bones and chest became evident, hand contractures developed, and the presumed large omphalocele was in part found to be a large ventral hernia, as echogenic adipose tissue could be seen in the abdominal wall near to the cord insertion. Prenatal findings were confirmed after delivery and central nervous system imaging revealed lissencephaly. The combination of an abdominal wall defect with either increased nuchal translucency or skeletal abnormalities should prompt an investigation for uniparental disomy 14 even if the karyotype is normal.

Dilated coronary sinus in the fetus: misinterpretation as an atrioventricular canal defect.

The ostium of the coronary sinus opens directly into the right atrium in close proximity to the insertion of the atrioventricular values. If the coronary sinus is dilated, it can create the appearance of atrioventricular canal defect in the fetal echocardiographic four-chamber view. The diagnosis of a serious heart lesion, such as a canal defect, necessitates decisions regarding pregnancy termination or optimal timing/location of delivery. We present three women who were referred at 23, 36 and 38 weeks' gestation with a preliminary diagnosis by level II ultrasound of a fetal atrioventricular canal defect. In each patient, the targeted fetal echocardiogram demonstrated a dilated coronary sinus and no evidence of an atrioventricular canal defect. The fetal echocardiographic presentation of a dilated coronary sinus can be mistaken for an atrioventricular canal defect. Misdiagnosis can be avoided by utilizing both variable angulation in the four-chamber projection and additional transducer views to confirm an intact atrioventricular septum and two normal atrioventricular valves.

The safety and utility of pulmonary artery catheterization in severe preeclampsia and eclampsia.

OBJECTIVE: The objective of this research was to study the safety and utility of pulmonary artery catheterization in the management of severe preeclampsia and eclampsia. STUDY DESIGN: In a retrospective chart review from January 1, 1995, through December 31, 1997, a total of 115 patients admitted to the obstetric intensive care unit at Groote Schuur Hospital were found to have required placement of a pulmonary artery catheter. From this population 100 maternal charts were examined for medical and pregnancy history, including indication for pulmonary artery catheter placement, hemodynamic readings, complications, and subsequent management. RESULTS: The initial indications for pulmonary artery catheter placement in cases of severe preeclampsia or eclampsia were renal failure in 53 cases (53%), pulmonary edema in 30 (30%), and eclampsia in 17 (17%). Subjective evaluation demonstrated that the pulmonary artery catheter was helpful in determining management in 93 cases (93%). There was a 4.0% complication rate, which included three venous thromboses and one case of cellulitis. Eleven patients required dialysis, and 3 women died. The mean (+/-SE) duration of catheter placement was 2.1 +/- 0.1 days and the mean (+/-SE) intensive care unit and hospital stays were 3.4 +/- 0.2 days and 11.4 +/- 0.8 days, respectively. The pulmonary artery catheter measurements of pulmonary artery wedge pressure and central venous pressure were increased in the cases of pulmonary edema (21.0 +/- 2.0 mm Hg and 9. 6 +/- 1.2 mm Hg, respectively) but were normal in the cases of renal failure and eclampsia. CONCLUSION: Despite significant maternal morbidity and mortality, pulmonary artery catheter use in cases of severe preeclampsia or eclampsia was subjectively beneficial in 93 of 100 cases (93%), with an acceptable complication rate (4.0%).

Effect of mode of delivery in nulliparous women on neonatal intracranial injury.

BACKGROUND: Infants delivered by vacuum extraction or other operative techniques may be more likely to sustain major injuries than those delivered spontaneously, but the extent of the risk is unknown. METHODS: From a California data base, we identified 583,340 live-born singleton infants born to nulliparous women between 1992 and 1994 and weighing between 2500 and 4000 g. One third of the infants were delivered by operative techniques. We evaluated the relation between the mode of delivery and morbidity in the infants. RESULTS: Intracranial hemorrhage occurred in 1 of 860 infants delivered by vacuum extraction, 1 of 664 delivered with the use of forceps, 1 of 907 delivered by cesarean section during labor, 1 of 2750 delivered by cesarean section with no labor, and 1 of 1900 delivered spontaneously. As compared with the infants delivered spontaneously, those delivered by vacuum extraction had a significantly higher rate of subdural or cerebral hemorrhage (odds ratio, 2.7; 95 percent confidence interval, 1.9 to 3.9), as did the infants delivered with the use of forceps (odds ratio, 3.4; 95 percent confidence interval, 1.9 to 5.9) or cesarean section during labor (odds ratio, 2.5; 95 percent confidence interval, 1.8 to 3.4), but the rate of subdural or cerebral hemorrhage associated with vacuum extraction did not differ significantly from that associated with forceps use (odds ratio for the comparison with vacuum extraction, 1.2; 95 percent confidence interval, 0.7 to 2.2) or cesarean section during labor (odds ratio, 0.9; 95 percent confidence interval, 0.6 to 1.4). CONCLUSIONS: The rate of intracranial hemorrhage is higher among infants delivered by vacuum extraction, forceps, or cesarean section during labor than among infants delivered spontaneously, but the rate among infants delivered by cesarean section before labor is not higher, suggesting that the common risk factor for hemorrhage is abnormal labor.

Confined placental mosaicism for trisomy 14 and maternal uniparental disomy in association with elevated second trimester maternal serum human chorionic gonadotrophin and third trimester fetal growth restriction.

A case of confined placental mosaicism (CPM) and maternal uniparental isodisomy 14 identified after placental karyotype revealed trisomy 14 in a newborn with intrauterine growth restriction (IUGR) and minor dysmorphic features is reported. During the second trimester of the pregnancy, multiple marker screening revealed an increased risk for Down syndrome of > 1 in 10. The maternal serum human chorionic gonadotrophin (MShCG) was markedly elevated at 4.19 MoM. Amniocentesis revealed a normal 46,XX karyotype. Fetal growth restriction has been associated with elevated MShCG and placental aneuploidy with CPM for chromosomes 2, 7, 9 and 16. The present case of CPM for chromosome 14 was also associated with fetal growth restriction and elevated second trimester MShCG, suggesting a common link. Further studies need to be done to determine if indeed elevation of second trimester MShCG is associated with increased risk of CPM. The present case again demonstrates the need to perform placental karyotype in unexplained fetal growth restriction.

Ultrafast laser scanner microscope: design and construction.

The design of an ultrafast laser scanner microscope has been completed, and an experimental model has been constructed. Details of the novel objective lens design, the automatic focus system, the high-speed polygon scanner and the fast clock system are given. Results from initial tolerance testing as well as the first recorded images are presented.