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Biomedical subjects

G Critchfield

Publications and source records attributed to G Critchfield.

8 recordsLinked to original sources
PubMed1998

Detection of anomalies: alternatives to ultrasound.

Ultrasound and biochemical screening are complementary screening tests that each have limitations and advantages. The next several years will see variable progress in the evolution of these techniques, which, it is hoped, will result in an appropriate role for each to achieve a cost-effective, highly sensitive and specific screening approach that will allow couples the most comfort in detecting problems during pregnancy, as well as a high degree of confidence that normal results are accurate.

Algorithms↗
PubMed1998

Fetal gender impact on multiple-marker screening results.

Maternal serum alpha-fetoprotein (MSAFP), human chorionic gonadotropin (hCG), and unconjugated estriol (uE3) are used in combination with maternal age to calculate the risk for Down syndrome (DS) in pregnancy. Increased levels of hCG and decreased levels of MSAFP and uE3 are consistent with an increased risk for DS. We retrospectively evaluated second-trimester maternal serum marker levels in a large cohort of patients with known normal outcomes and documented fetal gender. These included 15,428 patients who had MSAFP measurements, 11,428 patients with both MSAFP and hCG, and 6,090 patients with all three markers including uE3. MSAFP levels in patients with female fetuses were consistently lower than those with males. Conversely, hCG was higher in pregnancies with females as compared to males. No gender-related difference was noted for uE3. These results would suggest that the computed DS risk for female fetuses is higher than for males, despite the fact that the incidence of DS is similar in both genders. This information could be useful for calculating gender-specific DS risk; however, this would require ultrasonographic determination of fetal sex.

Biomarkers↗
PubMed1998

Combination of elevated maternal serum alpha-fetoprotein (MSAFP) and low estriol is highly predictive of anencephaly.

Increased levels of second trimester maternal serum alpha-fetoprotein (MSAFP) have long been established as a marker for neural tube defects (NTDs). In addition, decreased levels of maternal estriol in the third trimester have been reported in pregnancies with anencephalic fetuses. The purpose of this study was to evaluate whether early second trimester unconjugated serum estriol (uE3) is an independent predictor of NTDs. The study included 57,031 patients who underwent maternal serum screening with MSAFP at 14-22 weeks gestation. Of these, 23,415 also had uE3 measurements. There were 63 cases of NTD, an overall incidence of 1.1 per 1,000. Elevated MSAFP (> or =2.5 MOM) was detected in 1,346 patients, 48 of which had NTDs. Decreased uE3 (< or =0.5) was detected in 1,437 patients, 17 of which had NTDs. The incidence of NTDs was significantly higher in patients with low uE3, compared to patients with normal/high uE3 (1.15% vs. 0.09%, P < 001). Finally, 51 patients had both increased MSAFP and decreased uE3; 16 of these had NTDs, 14 of which were anencephalics. In conclusion, both elevated MSAFP and low maternal serum estriol are predictive of NTD but have a low sensitivity. The combination of abnormally elevated MSAFP and low estriol is highly predictive of NTD in particular anencephaly.

Anencephaly↗
PubMed1998

Effect of adjustment of maternal serum alpha-fetoprotein levels in insulin-dependent diabetes mellitus.

Our objective was to determine the effect of the 20% upward adjustment of maternal serum alphafetoprotein (MSAFP) in patients with insulin-dependent diabetes mellitus (IDDM) on the number of patients that would be classified at increased risk for pregnancy complicated by either Down syndrome (DS) or neural tube defect (NTD). We retrospectively evaluated a database containing 63,110 patients who underwent multiple serum marker screening between 14 and 22 weeks gestation; 620 patients with IDDM had measurements of MSAFP of which 479 also had measurements of beta-HCG, allowing calculation of DS risk. Increased NTD risk was defined as MSAFP >2.5 MOM while increased DS risk was defined as a calculated risk > or =1/270. One IDDM patient delivered an infant with a NTD; it was not detected on serum screening. No infants were born with DS. Of the 620 patients with MSAFP determinations, 9 had values >2.5 MOM before adjustment. After upward adjustment, 7 additional patients were identified. Sixteen patients were identified at increased risk for DS before and after adjustment. Our data suggest that the 20% upward adjustment of MSAFP increases by 78%, the number of patients who would require further evaluation for NTD's. Although we were able to identify 620 women with IDDM who underwent serum screening for NTD, the low prevalence of NTD's did not allow us to demonstrate an increased detection rate. The effect of upward adjustment of MSAFP on the number of patients categorized at increased DS risk appears to be minimal.

Adult↗
PubMed1981

Dermatoglyphic feature of myocardial infarction patients.

An association reported between certain dermatoglyphic features and myocardial infarction (MI) in Japanese males is investigated using a sample of Caucasian males. The frequencies in each of the four Galtonian pattern types (arch, ulnar loop, radial loop, whorl) defined on each of the ten primary digital pattern areas, as well as several synthetic fields for the MI and control groups, are compared. Total and absolute finger ridge count for the same pattern areas in the two samples are similarly studied. No differences in the distributions of these features significant at the 0.01 level or less could be demonstrated between the MI and control samples. A search for combinations of features to correctly classify the individuals into the two groups was similarly inconclusive. Differences in sample size and racial homogeneity that may account for this failure to reproduce the results of the study of Japanese males are discussed. Finally, statistics describing the distributions of the dermatoglyphic features in the test and control samples are presented for comparison with future investigations.

Dermatoglyphics↗
PubMedDate not supplied

Distribution of neural tube defects as a function of maternal weight: no apparent correlation.

OBJECTIVES: Maternal nutritional deficiency is an important predisposing factor to congenital neural tube defects (NTDs). It was hypothesized that obese women may have an increased risk for NTDs. The aim of the present study was to address this question in a large cohort. METHODS: A total of 72,915 consecutive cases of biochemical screening that had documented maternal weights and pregnancy outcomes were identified from the Quest Diagnostic Laboratories database. Patients were divided into five ranges of maternal weights, and the incidence of NTDs was calculated for each group. Based on the different definitions of maternal overweight, the data were also analyzed based on 2 groups only, obese and nonobese, using three cutoff points. RESULTS: Seventy-nine pregnancies were complicated by NTDs (incidence of 1.08 per 1,000 pregnancies). Differences between maternal weights ranges were not found to be statistically significant (chi2 = 5.997, p = 0.19, power = 0.99). Differences between obese and nonobese mothers were not found to be statistically significant for all three analyses as well. CONCLUSIONS: Our present results do not support an association between maternal obesity and NTDs.

Body Weight↗