Biomedical subjects

K Schuchter

Publications and source records attributed to K Schuchter.

At least 19 recordsLinked to original sources

PubMed2006

Comparison between three-dimensional placental volume at 12 weeks and uterine artery impedance/notching at 22 weeks in screening for pregnancy-induced hypertension, pre-eclampsia and fetal growth restriction in a low-risk population.

OBJECTIVES: To compare the value of three-dimensional placental volume at 12 weeks and uterine artery Doppler at 22 weeks for predicting pregnancy-induced hypertension (PIH), pre-eclampsia and fetal growth restriction in a low-risk population. METHODS: Over a 20-month period we calculated the placental quotient (PQ = placental volume/crown-rump length) at 11-13 weeks' gestation in all women with singleton pregnancies who booked for delivery in our hospital. At 22 weeks, in the same population, we calculated the mean pulsatility index (PI) of both uterine arteries and the presence of an early diastolic notch was noted. Logistic regression models, the PQ and Doppler parameters were used to compare the two screening methods for subgroups of pregnancy outcome. RESULTS: Complete outcome data were obtained in 2489 consecutive singleton pregnancies. Logistic regression models for the detection of pre-eclampsia had a sensitivity of 38.5% (PQ) vs. 44.8% (Doppler); for the detection of small-for-gestational age (SGA) the sensitivity was 27.1% (PQ) vs. 28.1% (Doppler) at a specificity of 90%. Taking a PQ of or= 90th centile and a bilateral notch, the sensitivity for detection of SGA was 25.0%, 20.2% and 22.0%, respectively; for PIH it was 9.5%, 4.8% and 4.8%; for pre-eclampsia without SGA it was 20.0%, 28%, 12%; for PIH/pre-eclampsia with SGA it was 30.8%, 46.1% and 69.2%. In the group with the most severe complications, in which delivery took place before 34 weeks, the sensitivity was 50.0%, 50.0% and 38.9%, respectively. CONCLUSIONS: PQ at 12 weeks and uterine artery Doppler at 22 weeks have similar sensitivities for predicting pre-eclampsia and fetal growth restriction, although uterine artery Doppler is marginally more sensitive for the prediction of pre-eclampsia. While both methods are insufficient for screening in a low-risk population, the PQ method has the potential advantage of being performed in the first trimester.

Adolescent↗

PubMed2003

Increased nuchal translucency and congenital heart defects in a low-risk population.

OBJECTIVE: Increased first-trimester nuchal translucency (NT) is a possible marker for congenital heart defects in euploid fetuses. In this study, we wanted to determine the sensitivity for congenital heart defects using the 95th centile of the NT as a cut-off point. METHODS: All women who booked for delivery in our hospital in the first trimester underwent NT measurement at a crown-rump length (CRL) of between 35 and 75 mm. In all euploid fetuses and newborns with isolated or associated CHD, NT was examined retrospectively and classified as normal (<95th centile according to CRL-dependent centiles in our own data) or increased (> or =95th centile). RESULTS: From a total of 12,978 euploid fetuses screened, 27 had CHD (22 isolated and 5 cases associated with additional malformations). Moreover, 7 of the 27 fetuses also had increased NT (26%). Increased NT was significantly more frequent in fetuses with associated CHD (4/5) than in those with isolated CHD (3/22, Yates corrected chi2 p=0.012). In fact, the relative risk for CHD was 6.6 times higher in fetuses with increased NT compared to those with normal NT. CONCLUSION: Increased NT for the detection of CHD performed less well than in other studies. Nevertheless, it can be used as an indication for fetal echocardiography.

Adolescent↗

PubMed2003

Placental growth from the first to the second trimester of pregnancy in SGA-foetuses and pre-eclamptic pregnancies compared to normal foetuses.

The aim of this study was to determine placental growth between 12-22 weeks in normal pregnancies compared to pregnancies complicated by foetal SGA and maternal pre-eclampsia (PE). The placentae of 1199 women were measured 3D sonographically at 12, 16 and 22 weeks of gestation. Placental volume growth was then calculated. Neonatal birthweight, birth centile and the occurrence of pre-eclampsia were recorded in every woman and correlated with placental growth (four groups: normals, SGA, PE, SGA+PE). SGA-placentae are already smaller at 12 weeks but then develop in a similar way to normal placentae. PE placentae are slightly, but significantly, larger at 12 weeks, grow rapidly until 16 weeks and then stop growing normally between 16 and 22 weeks. If SGA goes together with PE, both placental volume (PV) at 12 weeks as well as growth is reduced significantly. Nevertheless, placental growth between week 12 and 22 is too heterogeneous to justify using this method as a clinical tool, but it can provide new information on placental physiology underlying unfavourable obstetric outcomes.

Adult↗

PubMed2002

The first trimester 'combined test' for the detection of Down syndrome pregnancies in 4939 unselected pregnancies.

The high detection rate (DR) for Down syndrome (DS) pregnancies which can be achieved by measuring fetal nuchal translucency (NT) early in pregnancy can be improved by combining it with placental hormones [pregnancy-associated plasma protein A (PAPP-A) and free beta-human chorionic gonadotrophin (fbeta-hCG)] and maternal age ('combined test'). In this study we wanted to assess the DR using the 'combined test' in an unselected population of self-referred pregnant women at a false-positive rate (FPR) of about 5%. NT, PAPP-A, fbeta-hCG and maternal age were measured in all women with singleton pregnancies who booked for delivery in our hospital from 1 December 1997 to 31 April 2000 and who were between 10 and 13 completed weeks of gestation [crown-rump length (CRL) 35-70 mm]. The specific DS risk was calculated using the computer program Alpha Version 5aa (Logical Medical Systems, London, UK). A total of 4939 women were tested. Out of 14 DS pregnancies that occurred during this period of time, 12 were detected with the test. A total of 246 women had a false-positive test result in a non-DS pregnancy (FPR 5.0%). This makes the 'combined test' by far the best test for the detection of DS pregnancies in a low-risk population. The constant increase in maternal age at the time of delivery can also lead to an improved DR if a simple age-dependant protocol for DS detection is used, but only at the price of a much higher number of amniocenteses and subsequent abortions. The DR for DS can be increased much more markedly using the 'combined test' with a FPR that still remains at the level as it was in the early 1970s.

Abortion, Spontaneous↗

PubMed2002

First-trimester placental volume as a marker for chromosomal anomalies: preliminary results from an unselected population.

OBJECTIVE: To compare first-trimester placental volume in chromosomally abnormal and normal pregnancies. METHODS: Placental volumes were routinely recorded at the time of nuchal translucency thickness measurement at 10-13 weeks of gestation. This was done using customized three-dimensional ultrasound equipment and measurements were then converted to the placental quotient (placental volume/fetal crown-rump length). The possible difference in placental quotient between chromosomally normal and abnormal pregnancies was examined. RESULTS: A total of 2863 pregnancies was evaluated, including 17 with major chromosomal defects (nine cases of trisomy 21, four of trisomy 18, two of trisomy 13, and one each of Turner syndrome and 48,XXY + 21). The median placental quotient in the chromosomally abnormal group (0.67) was significantly lower than that in the normal fetuses (0.98). In nine of the 17 affected pregnancies the quotient was below the 10th centile of the normal range. CONCLUSIONS: Assessment of placental volume may prove to be useful in first-trimester risk assessment for chromosomal anomalies.

Adolescent↗

PubMed2001

Uterine artery Doppler and placental volume in the first trimester in the prediction of pregnancy complications.

OBJECTIVE: To evaluate placental volume and uterine artery Doppler in the first trimester in the prediction of pregnancies that subsequently develop pre-eclampsia, pregnancy-induced hypertension, preterm placental abruption or fetal growth restriction. METHODS: In 380 singleton pregnancies attending our center for nuchal translucency screening at 11-14 weeks of gestation, Doppler assessment of both uterine arteries was carried out for measurement of the pulsatility index and the mean pulsatility index of the two vessels was calculated. In addition, three-dimensional ultrasound was used to obtain images for subsequent measurement of placental volume. The 90th centile of the uterine artery mean pulsatility index and the 10th centile of the placental volume for crown-rump length (placental quotient) were calculated. These cut-offs were used for the prediction of pregnancy complications. RESULTS: Complications occurred in 36 (9.5%) of the 380 pregnancies, including 31 cases of fetal growth restriction, two of pregnancy-induced hypertension and abruption, two of pregnancy-induced hypertension, and one of abruption. The uterine artery mean pulsatility index was > or =90th centile in 38 (10%) pregnancies and this group contained nine (25%) of those that developed complications. The placental quotient was < or =10th centile in 39 (10%) pregnancies and this group contained eight (22%) of those that developed complications. In eight (2%) pregnancies the uterine artery mean pulsatility index was > or =90th centile and the placental quotient was < or =10th centile and this group contained six (17%) of those that developed complications. CONCLUSION: The combination of placental volume measurement and uterine artery Doppler in the first trimester may identify women at risk for subsequent development of pregnancy complications.

Female↗

PubMed2001

Sequential screening for trisomy 21 by nuchal translucency measurement in the first trimester and maternal serum biochemistry in the second trimester in a low-risk population.

OBJECTIVE: To evaluate screening for trisomy 21 in a low-risk population utilizing a combination of nuchal translucency measurement in the first trimester and the triple test in the second trimester. METHODS: This was a retrospective study of 9342 women with singleton pregnancies who booked for delivery in our hospital over a period of 5 years. A nuchal translucency scan was carried out at 10-13 weeks' gestation and for those with a measurement of 3.5 mm or more chorionic villus sampling was performed. All other women were asked to return for the triple test at 16 weeks' gestation. Amniocentesis was offered to women in whom the nuchal translucency was 2.5-3.4 mm, the triple test showed a risk of > or = 1 : 250 and in women aged > or = 35 years. RESULTS: The detection rate using the combined screening method was 95% (18/19) with a screen-positive rate of 7.2%. In comparison, screening by maternal age alone would have identified nine (47%) trisomy 21 pregnancies with a screen-positive rate of 10.7%. CONCLUSION: Our data suggest that the combination of nuchal translucency measurement in the first trimester and the triple test in the second trimester is associated with a very high detection rate of trisomy 21 at a relatively low screen-positive rate.

Adolescent↗

PubMed2001

Three-dimensional sonographic volumetry of the placenta and the fetus between weeks 15 and 17 of gestation.

OBJECTIVES: Three-dimensional sonographic volume measurement enables for the first time direct comparison of the increase in size of different but closely interacting structures like the placenta and fetus. Our aim was to calculate the fetal and placental volumes between weeks 15 and 17 of gestation, to monitor the difference in the increase of the fetal and placental sizes and to determine their mutual relationship. METHODS: Fetal and placental sonographic volume measurements were made in 356 singleton pregnancies. To measure the relationship between fetal and placental volumes, a quotient was calculated. Regression analyses were performed to analyze the dependence of the fetal and placental volumes and placental quotient on the week of gestation and other influencing variables. RESULTS: The mean of the fetal volume increased markedly from 67.8 to 76.6 mL (by 13%) within the 3 weeks of observation, whereas placental volume increased only slightly (111.1 to 114 mL (by 2.6%)). The random variation of placental volumes around the mean in all three gestational weeks was considerably higher than that of fetal volumes, indicating that in this early period of gestation there is little correlation between fetal and placental sizes. Fetal volume correlated better to gestational week than did placental volume. CONCLUSION: The quotient of fetal and placental volume might assist in the diagnosis of high-risk pregnancies and the assessment of a normal or large fetus with a small placenta.

Anthropometry↗

PubMed2001

Three-dimensional ultrasound measurement of the placental volume in early pregnancy: method and correlation with biochemical placenta parameters.

Placental size has been an interesting topic of research for many years. The main aim of this study was to investigate the feasibility of measuring the placental volume at the end of the first trimester using three-dimensional (3D) ultrasound and to correlate these volumes to known placental functional indices and to factors affecting the placenta. Women with singleton pregnancies at the end of the first trimester were included into this study. The volume data of the placentae were correlated to the crown-rump length (CRL), placenta-associated plasma protein A (PAPP-A), free beta-human chroangiogonadotropin (f-beta-hCG) and other factors that may affect the placental size or function. A total of 1462 pregnancies could be evaluated. Comparison between CRL and placental volume proved a significant correlation (r=0.43, P< 0.001). Due to the observed proportional growth of CRL and placental volume, a quotient (placental volume/CRL) was calculated for each case. There were no differences between placenta/CRL-quotients in relation to gravidity, parity or smoking. Correlations could be established between the placental volume and PAPP-A and f-beta-hCG (PAPP-A: r=0.28, P< 0.001, f-beta-hCG: r=0.10, P< 0.001). The measurement of the placenta in the first trimester can be performed in a high percentage of cases. The placenta/CRL quotient represents a simple method to compare placentae from different gestational days. The correlation between placental volume and maternal serum screening parameters might provide a chance to refine first trimester Down's syndrome serum screening. Future studies will be needed to evaluate the possible clinical use of first trimester placental volume measurements.

Chorionic Gonadotropin, beta Subunit, Human↗

PubMed2000

Uterine artery Doppler perfusion in the first and second pregnancies.

OBJECTIVE: To compare blood perfusion expressed as pulsatility index (PI) and 'notching' of the left and right uterine arteries measured in the same woman in her first and second pregnancies. METHODS: Data from 1102 women's uterine perfusion in their first and second pregnancies were evaluated. Bilateral data, PI and early diastolic notch in both pregnancies were collected. A notch and a PI > or = 1 were deemed to be pathologic. Statistical mean and standard deviation together with the frequency of pathological uterine perfusion in the first and second pregnancies were compared (t-test, chi 2-test). RESULTS: PI values did not differ significantly in the first and second pregnancies whereas there was a small but marked difference in the right uterine artery compared to the left. Early diastolic notch behaved differently, being more frequently found in the first pregnancy. This discrepancy was highly significant. However in subsequent pregnancies a notch was found more frequently on the left than on the right side. Women with pathologic flow patterns in the first pregnancy were significantly more likely to develop pathologic flow patterns in their second pregnancy. CONCLUSION: Although uterine perfusion in the same woman is similar in the first and second pregnancies, 'notching' appears much more frequently in the first pregnancy reflecting the fact that the decidual embedding of the trophoblast is less problematic in the second pregnancy. Nevertheless the subgroup with an early diastolic notch in their first pregnancy is four times more likely to develop a notch in a second pregnancy.

Arteries↗

PubMed1999

Influence of cigarette-smoking on the result of the triple test.

The aim was to establish whether the risk of trisomy 21 in women smokers undergoing triple test differs to women nonsmokers, whether increased smoking changes the hormonal values, and if the cessation of smoking at the beginning of pregnancy has any influence on the triple test. 1,854 pregnant women were interviewed regarding their smoking habits at the time of the triple test. They were divided into 5 groups: (a) nonsmokers; (b) smokers before pregnancy; (c) 1-5 cigarettes; (d) 6-10; (e) 11 or more. MOM values of AFP, E3 and beta-HCG and Down risk calculated by the triple test were compared within the 5 groups. Increasing smoking was associated with a reduction in MOM values of beta-HCG. Smokers were significantly less likely to be counseled for karyotyping (cut-off level 1:250) than nonsmokers. The values of women who stopped smoking at the beginning of pregnancy were not different to nonsmokers. The results suggest the benefits of inclusion of smoking habits for the calculation of the triple test.

Adult↗

PubMed1999

Prenatal diagnosis of unilateral megalencephaly by 2D and 3D ultrasound: a case report.

Unilateral megalencephaly is a rare malformation of the central nervous system characterized by an overgrowth of one cerebral hemisphere due to an anomaly of neuronal cell migration. It shows macroscopic and histological alterations of the central nervous tissue. We report on a case of this malformation detected prenatally with the support of 3D ultrasonography.

Abortion, Induced↗

PubMed1998

Detection of fetal congenital heart disease in a low-risk population.

Our purpose was to evaluate the efficacy of level two ultrasound screening for the detection of congenital heart defects (CHD) in a low-risk population by using three standardized cuts. Within a period of four years a total of 6727 pregnant women of a low-risk population undertook several ultrasound examinations on the basis of screening for fetal malformations. All ultrasound examinations were performed by three experienced doctors. At every single scan three standardized cuts (apical and lateral four-chamber view, crossing over of the great arteries) were obtained in order to detect congenital heart defects. Of 87 CHDs (1.33 per cent of the examined women) 39 (43.8 per cent) were diagnosed prenatally. The detection rate was 10/48 (20.8 per cent) in the presence of VSD, ASD2 or combined ASD2 + VSD, the detection rate was 29/39 (74.3 per cent) in the presence of other forms of congenital heart disease. None of the 38 missed cases in the first group but three of the ten missed CHDs in the second group had emergency neonatological problems. Aneuploidy and/or other malformations existed in 22/87 cases of CHD. The obstetrical management was changed in nearly all cases after the diagnosis of a CHD. Twenty-two women opted for termination of pregnancy because of additional fetal malformations or chromosomal defects. Five women were transferred prenatally to a tertiary centre for neonatal cardiac surgery. Ten deliveries were performed in the presence of a neonatologist. Good detection rates for CHD can be achieved in a low-risk population on the basis of level two ultrasound screening by using the above mentioned three cuts and thus, the perinatal mortality and morbidity can be improved.

Abnormalities, Multiple↗

PubMed1998

Group B streptococci during pregnancy: a comparison of two screening and treatment protocols.

OBJECTIVE: The objective was to evaluate whether the rate of neonatal group B streptococcal infection could be reduced by screening for group B streptococci during the third trimester of pregnancy. STUDY DESIGN: Two periods in which different screening and treatment protocols were applied were compared. In period A all mothers showing high-risk factors were given peripartal antibiotic coverage. In period B vaginal and rectal smears were routinely obtained in gestational week 34 and cultured for group B streptococci. If culture results were positive, the woman received peripartal antibiotics. The incidence of group B streptococcal infections and the number of peripartal antibiotic doses were established by comparing 3700 neonates (3623 mothers) in period A with 3648 neonates (3569 mothers) in period B. RESULTS: In period A, 20 group B streptococcal infections were recorded. Of these, 5 were severe to life-threatening. In period B, 4 group B streptococcal infections were observed. Two were severe and occurred in neonates born before the mothers could be screened. Another 2 were mild and occurred in neonates whose mothers had negative screening test results. The reduction was significant by the chi2 test (chi2 = 9.19, Yates' corrected P = .0024). The rates of peripartal antibiotic treatment were 11.9% in period A and 14.5% in period B. CONCLUSION: Although no neonate died of group B streptococcal sepsis in either of the 2 periods, the protocol used in period B clearly reduced the incidence of group B streptococcal infection. The number of peripartal antibiotic doses required was not much higher than in period A. Screening for group B streptococci in week 34 seems to be a valuable contribution to further improvement of neonatal outcome.

Anti-Bacterial Agents↗

PubMed1998

Second-trimester measurements of placental volume by three-dimensional ultrasound to predict small-for-gestational-age infants.

OBJECTIVE: The objective of this study was to investigate the value of second-trimester three-dimensional sonographic placental volume measurements to predict infants who are below the 10th centile for birth weight. SUBJECTS AND METHODS: Placental volume measurements were performed using three-dimensional ultrasound in 382 women with normal singleton pregnancies at 16-23 weeks' gestation. Logistic multivariate regression consisting of variables considered to influence birth weight was used to predict infants with a birth weight below the 10th centile from the placental volume measurements. RESULTS: Prognostic influence could be shown for placental volume (p < or = 0.0001), gestational week at the time of measurement (p = 0.0002) and maternal weight at the time of registration (p = 0.0025). Values for specificity and sensitivity achieved by choosing an 'optimal' cut-off point of 0.16 for the estimation probability for a small-for-gestational-age (SGA) infant were low at 82.5% and 52.5%, respectively. CONCLUSIONS: Three-dimensional sonographic measurement of the placental volume alone is not a satisfactory technique for predicting SGA infants.

Adult↗

PubMed1998

Results of routine fetal nuchal translucency measurement at weeks 10-13 in 4233 unselected pregnant women.

The aim of this study was to determine the value of nuchal translucency (NT) measurement for the detection of aneuploidies and other malformations in a low-risk population. In total, 4233 women who booked in our hospital for delivery were examined between the tenth and 13th week of gestation. Of the 17 chromosomal abnormalities that occurred, 11 were detected using the measurement of NT (65 per cent). Only three of the seven Down syndrome pregnancies were detected using this technique (43 per cent). The remaining four Down syndrome babies were diagnosed either because of positive biochemical testing or by amniocentesis because of maternal age. A total of 69 serious malformations including chromosomal defects were detected during the study period. In 18 of these cases, the NT measurement was > or = 2.5 mm (26 per cent). Most of the malformations without aneuploidies were of cardiac origin. The data show that the NT measurement is a valuable marker for aneuploidy even in a low risk-population. It is also of value in the diagnosis of other serious malformations, particularly cardiac defects.

Abortion, Spontaneous↗

PubMed1998

The distribution of nuchal translucency at 10-13 weeks of pregnancy.

There is a need for a simple method of expressing nuchal translucency measurement in early pregnancy that will allow for gestational age and be useful in screening for Down's syndrome. To achieve this objective, we conducted a prospective study of 561 women with singleton pregnancies that were not affected by Down's syndrome at 10-13 weeks of gestation. Nuchal translucency measurements and crown rump length measurements were determined. Nuchal translucency measurement increased by about 17 per cent per week. Expressing the result as a multiple of the median (MOM) nuchal translucency for a given crown rump length allowed for this increase with gestational age and yielded a distribution of values that was approximately Gaussian. About 96 per cent of values lay between 0.5 and 2.0 MOM. The variance and therefore the false-positive rate of nuchal translucency were significantly reduced by recording several measurements and using the average: for example, the false-positive rate reduced from 8.3 per cent to 5.0 per cent if the average of six measurements were used instead of one--a potential 40 per cent reduction in the false-positive rate if the test were used in screening. Estimating the distribution of nuchal translucency in MOM values will assist in specifying the statistical parameters to be used in prenatal screening for Down's syndrome and the use of repeated nuchal translucency measurements is expected to have a useful effect on reducing the screening false-positive rate at a given MOM cut-off level.

Adult↗

PubMed1997

Prenatal diagnosis of facial malformations.

In a prospective study, 5407 pregnant women were screened by ultrasound to detect malformations of the fetal face. Of a total of 11 facial anomalies, eight were detected by prenatal ultrasound (72 per cent). Three pregnancies were terminated because of associated developmental abnormalities or aneuploidy. In all of them, the facial malformations were correctly diagnosed. When associated with other developmental abnormalities, facial malformations were picked up at a rate of 100 per cent. Isolated facial malformations, by contrast, were detected in no more than 50 per cent of cases. Eight cases with suspected facial dysmorphism ended with the delivery of normal babies (specificity 99.8 per cent). None of them prompted karyotyping or any other invasive testing. Only two correctly detected facial malformations (bilateral cleft lips/palate) had a minor influence on obstetrical management. There would not have been disadvantages for the newborns in any of the cases if the malformations had been missed.

Acrocephalosyndactylia↗