Biomedical subjects

D Towner

Publications and source records attributed to D Towner.

5 recordsLinked to original sources

PubMed2004

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.

Cervix Uteri↗

PubMed2001

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.

Abnormalities, Multiple↗

PubMed1999

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.

Birth Injuries↗

PubMed1995

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.

Abnormalities, Drug-Induced↗

PubMed1981

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.

Microscopy↗