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David A Nyberg

Publications and source records attributed to David A Nyberg.

15 recordsLinked to original sources
PubMed2006

Is there a nuchal translucency millimeter measurement above which there is no added benefit from first trimester serum screening?

OBJECTIVE: The purpose of this study was to evaluate whether there is a nuchal translucency (NT) measurement, independent of gestational age, above which immediate diagnostic testing should be offered without waiting for first trimester serum markers. STUDY DESIGN: Thirty-six thousand one hundred twenty patients had successful measurement of simple NT at 10 3/7 to 13 6/7 weeks and had first trimester serum screening. No risks were reported until second trimester serum screening was completed. RESULTS: Thirty-two patients (0.09%) had NT > or = 4.0 mm; the lowest combined first trimester trisomy 21 risk assessment in euploid cases was 1 in 8 and among aneuploidy cases was 7 in 8. One hundred twenty-eight patients (0.3%) had simple NT > or = 3.0 mm: the lowest combined first trimester trisomy 21 risk assessment of any patient in this group was 1 in 1479 and the lowest risk assessment among aneuploid cases was 1 in 2. Ten patients (8%) had first trimester trisomy 21 risk assessments lowered to less that 1:200 and none of these 10 cases had an abnormal outcome. CONCLUSION: During first trimester Down syndrome screening, whenever an NT measurement of 3.0 mm or greater is obtained there is minimal benefit in waiting for serum screening results, and no benefit for NT of 4.0 mm or greater. Differentiation between cystic hygroma and enlarged simple NT (> or = 3.0 mm) is now a moot point as both are sufficiently high risk situations to warrant immediate CVS.

Chorionic Gonadotropin, beta Subunit, Human↗
PubMed2006

First-trimester screening.

Screening for fetal chromosome abnormalities, particularly for trisomy 21, has made dramatic advances. Better screening demonstrates that "high-risk" patients--particularly over age 35--can have lower risk of defects than younger unscreened women. This has caused reduction of amniocentesis for older patients and made screening available for younger patients who have the universal 2% to 3% risk. This means lower procedural-related losses of normal fetuses, and better resource allocation. The trend toward first-trimester detection of structural defects continues; a normal survey is reassuring and helps exclude major defects. Based on screening results, patients can be triaged into early follow-up and possible amniocentesis as 14 to 16 weeks, or a later detailed anatomic survey at 18 to 20 weeks.

Female↗
PubMed2006

Comparison of serum markers in first-trimester down syndrome screening.

OBJECTIVE: To estimate patterns of total hCG and inhibin A levels in the late first trimester of Down syndrome pregnancies, compare them with that of free beta-hCG, and assess screening performance of these markers individually and in combination with pregnancy-associated plasma protein-A (PAPP-A) and nuchal translucency. METHODS: Seventy-nine matched case-control sets of maternal serum samples (each Down syndrome case matched to 5 controls) from 11 through 13 completed weeks of gestation were taken from the sample bank of the First and Second Trimester Evaluation of Risk Consortium, a population-based study, and assayed for levels of free beta-hCG, total hCG, and inhibin A. Distribution characteristics and correlations of the multiples of the median values were estimated in cases and controls. Screening performance for each marker, alone and in combination with PAPP-A, nuchal translucency, and maternal age, was calculated. RESULTS: Median multiples of the median levels of free beta-hCG, total hCG, and inhibin A in cases were more elevated as gestation increased from 11 to 13 weeks, with univariate detection rates of 31%, 23%, and 29%, respectively, at a 5% false-positive rate. At 12 weeks, the multivariate detection rates at a 5% false-positive rate for nuchal translucency and PAPP-A (with maternal age) with either free beta-hCG, total hCG, or inhibin A were 84%, 83%, and 85%, respectively. The improvement in performance from nuchal translucency and PAPP-A to any of the three-marker tests was significant, while performance of any of the three-marker combinations was not significantly different from each other. CONCLUSION: Although levels of free beta-hCG in affected pregnancies were higher earlier than the levels of either total hCG or inhibin A, there was no significant difference in screening performance when either of the three markers was used with nuchal translucency and PAPP-A at 11-13 weeks of pregnancy. LEVEL OF EVIDENCE: II-2.

Adult↗
PubMed2005

First-trimester or second-trimester screening, or both, for Down's syndrome.

BACKGROUND: It is uncertain how best to screen pregnant women for the presence of fetal Down's syndrome: to perform first-trimester screening, to perform second-trimester screening, or to use strategies incorporating measurements in both trimesters. METHODS: Women with singleton pregnancies underwent first-trimester combined screening (measurement of nuchal translucency, pregnancy-associated plasma protein A [PAPP-A], and the free beta subunit of human chorionic gonadotropin at 10 weeks 3 days through 13 weeks 6 days of gestation) and second-trimester quadruple screening (measurement of alpha-fetoprotein, total human chorionic gonadotropin, unconjugated estriol, and inhibin A at 15 through 18 weeks of gestation). We compared the results of stepwise sequential screening (risk results provided after each test), fully integrated screening (single risk result provided), and serum integrated screening (identical to fully integrated screening, but without nuchal translucency). RESULTS: First-trimester screening was performed in 38,167 patients; 117 had a fetus with Down's syndrome. At a 5 percent false positive rate, the rates of detection of Down's syndrome were as follows: with first-trimester combined screening, 87 percent, 85 percent, and 82 percent for measurements performed at 11, 12, and 13 weeks, respectively; with second-trimester quadruple screening, 81 percent; with stepwise sequential screening, 95 percent; with serum integrated screening, 88 percent; and with fully integrated screening with first-trimester measurements performed at 11 weeks, 96 percent. Paired comparisons found significant differences between the tests, except for the comparison between serum integrated screening and combined screening. CONCLUSIONS: First-trimester combined screening at 11 weeks of gestation is better than second-trimester quadruple screening but at 13 weeks has results similar to second-trimester quadruple screening. Both stepwise sequential screening and fully integrated screening have high rates of detection of Down's syndrome, with low false positive rates.

Adult↗
PubMed2005

Impact of maternal age on obstetric outcome.

OBJECTIVE: To estimate the effect of maternal age on obstetric outcomes. METHODS: A prospective database from a multicenter investigation of singletons, the FASTER trial, was studied. Subjects were divided into 3 age groups: 1) less than 35 years, 2) 35-39 years, and 3) 40 years and older. Multivariable logistic regression analysis was used to assess the effect of age on outcomes after adjusting for race, parity, body mass index, education, marital status, smoking, medical history, use of assisted conception, and patient's study site. RESULTS: A total of 36,056 women with complete data were available: 28,398 (79%) less than 35 years of age; 6,294 (17%) 35-39 years; and 1,364 (4%) 40 years and older. Increasing age was significantly associated with miscarriage (adjusted odds ratio [adjOR]2.0 and 2.4 for ages 35-39 years and age 40 years and older, respectively), chromosomal abnormalities (adjOR 4.0 and 9.9), congenital anomalies (adjOR 1.4 and 1.7), gestational diabetes (adjOR 1.8 and 2.4), placenta previa (adjOR 1.8 and 2.8), and cesarean delivery (adjOR 1.6 and 2.0). Patients aged 35-39 years were at increased risk for macrosomia (adjOR 1.4). Increased risk for abruption (adjOR 2.3), preterm delivery (adjOR 1.4), low birth weight (adjOR 1.6), and perinatal mortality (adjOR 2.2) was noted in women aged 40 years and older. CONCLUSION: Increasing maternal age is independently associated with specific adverse pregnancy outcomes. Increasing age is a continuum rather than a threshold effect.

Adult↗
PubMed2005

First-trimester septated cystic hygroma: prevalence, natural history, and pediatric outcome.

OBJECTIVE: To estimate prevalence, natural history, and outcome of septated cystic hygroma in the first trimester in the general obstetric population, and to differentiate this finding from simple increased nuchal translucency. METHODS: Patients at 10.3-13.6 weeks of gestation underwent nuchal translucency sonography as part of a multicenter clinical trial. Septated cystic hygroma cases were offered chorionic villi sampling for karyotype, and targeted fetal anatomical and cardiac evaluations. Survivors were followed up for fetal and long-term pediatric outcome (median 25 months, range 12-50 months). Cases of septated cystic hygroma were also compared with cases of simple increased nuchal translucency. RESULTS: There were 134 cases of cystic hygroma (2 lost to follow-up) among 38,167 screened patients (1 in 285). Chromosomal abnormalities were diagnosed in 67 (51%), including 25 trisomy-21, 19 Turner syndrome, 13 trisomy-18, and 10 others. Major structural fetal malformations (primarily cardiac and skeletal) were diagnosed in 22 of the remaining 65 cases (34%). There were 5 cases (8%) of fetal death and 15 cases of elective pregnancy termination without evidence of abnormality. One of 23 (4%) normal survivors was diagnosed with cerebral palsy and developmental delay. Overall, survival with normal pediatric outcome was confirmed in 17% of cases (22 of 132). Compared with simple increased nuchal translucency, cystic hygroma has 5-fold, 12-fold, and 6-fold increased risk of aneuploidy, cardiac malformation, and perinatal death, respectively. CONCLUSION: First-trimester cystic hygroma was a frequent finding in a general obstetric screening program. It has the strongest prenatal association with aneuploidy described to date, with significantly worse outcome compared with simple increased nuchal translucency. Most pregnancies with normal evaluation at the completion of the second trimester resulted in a healthy infant with a normal pediatric outcome.

Abortion, Therapeutic↗
PubMed2004

Threatened abortion: A risk factor for poor pregnancy outcome, a population-based screening study.

OBJECTIVE: The purpose of this study was to determine whether patients with first-trimester threatened abortion are at increased risk for poor pregnancy outcome. STUDY DESIGN: A large prospective multicenter database was studied. Subjects were divided into three groups: (1) no bleeding, (2) light bleeding, and (3) heavy bleeding. Univariate and multivariable logistic regression analyses were used. RESULTS: The study comprised 16,506 patients: 14,160 patients without bleeding, 2094 patients with light bleeding, and 252 patients with heavy bleeding. Patients with vaginal bleeding, light or heavy, were more likely to experience a spontaneous loss before 24 weeks of gestation (odds ratio, 2.5 and 4.2, respectively) and cesarean delivery (odds ratio, 1.1 and 1.4, respectively). Light bleeding subjects were more likely to have preeclampsia (odds ratio, 1.5), preterm delivery (odds ratio, 1.3), and placental abruption (odds ratio, 1.6). Heavy vaginal bleeding subjects were more likely to have intrauterine growth restriction (odds ratio, 2.6), preterm delivery (odds ratio, 3.0), preterm premature rupture of membranes (odds ratio, 3.2), and placental abruption (odds ratio, 3.6). CONCLUSION: First-trimester vaginal bleeding is an independent risk factor for adverse obstetric outcome that is directly proportional to the amount of bleeding.

Abortion, Spontaneous↗
PubMed2004

Obesity, obstetric complications and cesarean delivery rate--a population-based screening study.

OBJECTIVE: This study was undertaken to determine whether obesity is associated with obstetric complications and cesarean delivery. METHODS: A large prospective multicenter database was studied. Subjects were divided into 3 groups: body mass index (BMI) less than 30 (control), 30 to 34.9 (obese), and 35 or greater (morbidly obese). Groups were compared by using univariate and multivariable logistic regression analyses. RESULTS: The study included 16,102 patients: 3,752 control, 1,473 obese, and 877 morbidly obese patients. Obesity and morbid obesity had a statistically significant association with gestational hypertension (odds ratios [ORs] 2.5 and 3.2), preeclampsia (ORs 1.6 and 3.3), gestational diabetes (ORs 2.6 and 4.0), and fetal birth weight greater than 4000 g (ORs 1.7 and 1.9) and greater than 4500 g (ORs 2.0 and 2.4). For nulliparous patients, the cesarean delivery rate was 20.7% for the control group, 33.8% for obese, and 47.4% for morbidly obese patients. CONCLUSION: Obesity is an independent risk factor for adverse obstetric outcome and is significantly associated with an increased cesarean delivery rate.

Adult↗
PubMed2004

First-trimester nasal bone evaluation for aneuploidy in the general population.

OBJECTIVE: To evaluate the role of fetal nasal bone imaging at 10 3/7 to 13 6/7 weeks as a screening tool for aneuploidy, in a prospective multicenter trial. METHODS: Unselected patients from the general population with viable singleton pregnancies at 10 3/7 to 13 6/7 weeks were recruited at 15 U.S. centers. All had screening with nuchal translucency (NT) ultrasound by specially trained sonographers. In the last 8 months of this trial, first trimester nasal bone evaluation was added to the screening protocol. Nasal bones were described as present, absent, or unable to determine. RESULTS: A total of 38,189 patients completed first trimester NT screening, of whom 6,324 also underwent nasal bone sonography. An acceptable nasal image was obtained in 4,801 cases (76%), with nasal bones described as present in 4,779 (99.5%), and absent in 22 (0.5%). There were 11 identified cases of trisomy-21 in the population of 6,324 patients. In 9 of the 11 cases (82%) the nasal bones were described as present, and 2 cases were described as unable to determine. The only other aneuploidies were 2 cases of trisomy-18, in 1 of which the nasal bones were described as absent, and in 1 present. Absence of nasal bones had sensitivity for aneuploidy of 7.7%, false-positive rate 0.3%, and positive predictive value 4.5%. CONCLUSION: First-trimester nasal bone evaluation was not a useful test for population screening for trisomy-21 and added little to first-trimester NT screening. The difficulty in performing first-trimester nasal bone sonography consistently, in the general population setting, will significantly limit the usefulness of this aneuploidy screening technique.

Aneuploidy↗
PubMed2004

Correlation of second-trimester sonographic and biochemical markers.

OBJECTIVES: To investigate correlations between sonographic soft markers and biochemical markers (human chorionic gonadotrophin, alpha-fetoprotein, and estriol) for Down syndrome in the second trimester of pregnancy. METHODS: A total of 2183 women with apparently normal singleton fetuses who underwent second-trimester sonography (14-22 weeks) and maternal serum biochemical testing (triple test) were identified. Seven sonographic markers were recorded: nuchal fold thickness, humerus length, femur length, renal pyelectasis, hyperechoic bowel, echogenic intracardiac focus, and choroid plexus cysts. RESULTS: Weak negative but statistically significant correlations were observed between human chorionic gonadotropin (multiples of the median) and both femur length (multiples of the median; Spearman p = -0.073; P < .01) and humerus length (multiples of the median; Spearman p = -0.083; P < .01). No other correlations significant at the 1% level were observed between femur length (multiples of the median) or humerus length (multiples of the median) and the biochemical markers. There were no significant correlations between nuchal fold thickness and any of the 3 biochemical markers. At the 5% (P < .05) level, the median human chorionic gonadotropin level (multiples of the median) was lower when an echogenic intracardiac focus was detected. Hyperechoic bowel also tended to be associated with higher median human chorionic gonadotropin (multiples of the median) and alpha-fetoprotein (multiples of the median) levels (P < .05). CONCLUSIONS: We found that sonographic and biochemical markers for trisomy 21 are largely independent in unaffected pregnancies. For accurate risk estimation, correlations in both affected and unaffected pregnancies need to be considered. No or minimal correlation between sonographic markers and serum screening tests indicates that they can be used as independent modifiers of the maternal age-specific risk for Down syndrome.

Adult↗
PubMed2003

Use of genetic sonography for adjusting the risk for fetal Down syndrome.

Systematic evaluation of ultrasound findings known to be associated with trisomy 21, at an appropriate gestational age, has been referred to as a genetic sonogram. A number of high-risk centers performing genetic sonography have reported detection of ultrasound abnormalities in the majority of fetuses with fetal Down syndrome. However, nonspecific markers are more commonly observed than structural abnormalities, which are detected in less than 20% of cases in a nonselected population. Also, the actual sensitivity of a genetic sonogram will depend on various factors including the markers sought, gestational age, reasons for referral, and of course the quality of the ultrasound. Appropriate use of a genetic sonogram can help to modify the risk of fetal Down syndrome by decreasing the risk when the ultrasound is normal, or increasing the risk when specific ultrasound markers are detected. The postultrasound risk can be estimated by applying specific likelihood ratios, reflecting the strength of individual markers, with the a priori risk based on maternal age alone, or combined with biochemical markers when known. We review this approach of age-adjusted ultrasound risk assessment for fetal Down syndrome and illustrate how the risk can be estimated. Individual sonographic markers are also discussed.

Adult↗
PubMed2003

An 8-center study to evaluate the utility of mid-term genetic sonograms among high-risk pregnancies.

OBJECTIVE: A multicenter study was undertaken to evaluate the diagnostic efficacy of a genetic sonogram. METHODS: Eight centers provided data on 176 pregnancies complicated by fetal Down syndrome. One hundred thirty-four pregnancies were considered high risk because of advanced maternal age (> 35 years), and 42 were considered high risk for having "abnormal" triple-screen results (risk > 1:250). Each center provided fetal biometric data, information regarding the presence or absence of major structural abnormalities, and between 3 and 6 additional ultrasonographic markers for trisomy 21. The heterogeneity of our 8 independent "sensitivity estimates" was evaluated by Poisson regression, and a single combined estimate of the sensitivity was calculated. RESULTS: Of the total 176 cases of trisomy 21, 125 fetuses (71.0%) had either an abnormal long bone length (femur length, humerus length, or both), a major structural abnormality, or a Down syndrome marker. The combined diagnostic sensitivity was 71.6%, with a range of 63.6% (7 of 11) to 80% (8 of 10). Five centers had sensitivity estimates falling between 64% and 76%. The sensitivity of individual markers varied between 3% (sandal gap) and 46.5% (nuchal skin fold thickness). A condensed regimen of nuchal skin fold thickness, femur length, and a standard anatomic survey would screen in 56.8% of fetuses with Down syndrome. CONCLUSIONS: This 8-center study that included many fetuses with Down syndrome validates the concept that the genetic sonogram can be used to better adjust the Down syndrome risk for high-risk patients.

Biometry↗
PubMed2002

Correlation of ultrasound findings and biochemical markers in the second trimester of pregnancy in fetuses with trisomy 21.

OBJECTIVE: The aim of the present study was to assess possible correlations between ultrasound findings and maternal serum biochemical ('triple test') markers among fetuses with trisomy 21 in the second trimester of pregnancy. METHODS: The study was a retrospective cohort study of 72 pregnancies affected by trisomy 21 who had a second trimester ultrasound and biochemical screen performed at a single center between 1990 and 1999. The biochemical screen consisted of alpha-fetoprotein (AFP), total beta human chorionic gonadotrophin (hCG) and estriol (uE(3)). Marker levels were expressed in multiples of the median (MoM). The ultrasound findings assessed were major structural anomalies, short humerus length, short femur length, increased nuchal fold thickness (NF), hyperechoic bowel, echogenic intracardiac focus (EIF), ventriculomegaly, choroid plexus cysts and renal pyelectasis. RESULTS: Second trimester maternal serum biochemical markers and ultrasound findings appeared to be largely independent of each other. However, some significant correlations were observed. Estriol was significantly lower when a fetal cystic hygroma was detected on ultrasound compared to those with no cystic hygroma (0.40 vs. 0.70 MoM, p<0.05). The median hCG level was significantly lower in those pregnancies with a normal second trimester fetal ultrasound compared to those with positive ultrasound findings (2.07 vs. 2.87 MoM, p<0.05). Median hCG levels were also significantly higher in those cases with NF> or =5 mm as compared to those with NF<5 mm (2.99 vs. 2.49 MoM, p<0.05). This difference persisted after exclusion of the five cases with cystic hygromas (2.99 vs. 2.49 MoM, p<0.05). A significant positive correlation was observed between log(10) hCG and log(10) NF MoM (Spearman's rho=0.252, p<0.05). NF was significantly greater among fetuses with an identifiable cardiac defect compared with those without a detectable cardiac defect (median of 7.0 mm vs. 3.8 mm, p<0.01). This difference persisted when expressed as multiples of the median (2.8 vs. 1.3 MoM, p<0.01). CONCLUSION: Second trimester ultrasound and biochemical markers are largely independent in fetuses with trisomy 21, however significant correlations between the two were observed in the present series. These may be important in screening protocols that combine second trimester ultrasound and biochemical markers.

Chorionic Gonadotropin↗