Blood group O: A novel risk factor for increased postpartum blood loss?

INTRODUCTION

Blood group O is known to be associated with lower levels of von Willebrand factor (VWF) and with increased bleeding complications. The influence of blood group O on postpartum blood loss was assessed by a few studies, however, without adjustment for important obstetric risk factors for postpartum blood loss.

AIM

Aim of this study was to investigate whether women with blood group O exhibit increased blood loss after delivery in consideration of established risk factors for postpartum bleeding.

METHODS

A total of 1487 patients were prospectively included into this cohort study. Blood loss was assessed by estimated blood loss (in mL), and drop of haemoglobin (Δ haemoglobin) was calculated. Association of blood loss with risk factors (such as blood group O, cervical tears, morbidly adherent placenta, placenta praevia and uterine atony amongst others) was assessed with appropriate tests. Significant variables were entered into a stepwise multivariate regression analysis.

RESULTS

Women with blood group O showed a significantly higher blood loss when compared to women with blood group non-O (529.2 mL ± 380.4 mL and 490.5 mL ± 276.4 mL, respectively, P = .024)). The increased blood loss in women with blood group O remained significant after multivariate regression analysis (difference 47 mL, P = .019).

CONCLUSION

This is the first study reporting significantly increased blood loss following delivery in women with blood group O after adjustment for major risk factors for postpartum blood loss. Albeit having a statistically significant, but clinically minor effect on absolute blood loss, blood group O carriers may suffer from aggravated bleeding in the presence of additional obstetric bleeding pathologies.

Quality Requirements for the early Fetal Ultrasound Assessment at 11-13+6 Weeks of Gestation (DEGUM Levels II and III)

The early fetal ultrasound assessment at 11 - 13(+6) weeks of gestation remains the cornerstone of care despite the progress in diagnosing fetal chromosomal defects using cell-free fetal DNA (cffDNA) from the maternal circulation. The measurement of nuchal translucency (NT) allows the risk calculation for the fetal trisomies 21, 18 and 13 but also gives information on those fetal chromosomal defects which are at present unable to be detected using cffDNA. Nuchal translucency is the only auditable parameter at 11 - 13(+6) weeks and gives thus information on the quality of the first trimester anomaly scan. In addition it gives indirect information on the risks for fetal defects and for cardiac anomalies. Also the chances for a healthy live baby can be estimated. As experience with first trimester anomaly scanning increases, and the resolution of the ultrasound equipment has increased substantially, more and more details of the fetal anatomy become accessible at the first trimester scan. Therefore fetal anatomical defects and complex anomalies have become amenable to examination in the first trimester. This guideline describes compulsory and optional parameters for investigation at the first trimester scan and outlines a structured method of examining a first trimester fetus at 11 - 13(+6) weeks of gestation.

Continuous independent quality control for fetal nuchal translucency measurements provided by the cumulative summation technique

PURPOSE

The cumulative summation technique (CUSUM) is an innovative method for the quality control of nuchal translucency (NT) measurements. CUSUM allows immediate corrective intervention as soon as an unacceptable tendency is noted. The aim of this study was to implement an objective and dynamic quality control method based on the CUSUM technique for prompt analysis of fetal NT measurement which would be compatible with different standards in routine clinical practice. The findings were compared to the standard NT quality control methods currently in use.

MATERIALS AND METHODS

Three sets of fetal NT measurements performed by three experienced examiners (I, II and III) were selected for retrospective evaluation. One additional set of NT measurements performed by examiner IV was prospectively assessed to approve the practicability of the method. NT measurements were conducted according to the recommendations of Fetal Medical Foundation (FMF) Germany and London. NT values were converted to Z-scores. For quality and accuracy evaluation, data were fed into the Digisono CUSUM software to create double CUSUM charts of Z-scores. In addition, histograms were composed from the Z-scores of each set of measurements and plotted against a normal Gaussian distribution.

RESULTS

Three different patterns of retrospective performance and one set of NT measurements that was evaluated prospectively are presented. The full alignment of Z-scores using CUSUM curves reflected exact periods of under- and overestimation of NT measurements. The CUSUM chart of the prospective data set reveals that prompt corrective intervention of poor performance resulted in reconstitution of optimal results and provided sufficient control. In contrast, histograms of NT Z-scores only showed a minor positive or negative shift as compared to the expected values on the basis of Gaussian distribution, but could not identify poor performance.

CONCLUSION

Use of the CUSUM technique analysing the quality of sonographic NT measurements provides the possibility to prospectively observe the development of the examiner's skills, to maintain competence and to promptly define the time when inaccurate measurements start to occur.

Continuous independent quality control for fetal ultrasound biometry provided by the cumulative summation technique

OBJECTIVE

To apply the cumulative summation (CUSUM) technique for an evaluation of the learning process of sonographic fetal weight estimation at term in combination with the z-scores of biometry determinants and to assess the time of appearance and sources of errors.

METHODS

Learning curve (LC-CUSUM) and double CUSUM charts for systematic error detection based on absolute and signed mean percentage error were generated to retrospectively estimate the longitudinal accuracy of sonographic fetal weight estimation conducted by three trainees and one experienced examiner. For LC-CUSUM analysis an examination was considered to be a failure when there was an absolute error in birth weight estimation >/= 15%. Fetal biometry measurements (head circumference, abdominal circumference (AC) and femur length (FL)) from 227 routine ultrasound scans of one examiner were separately transformed into z-scores and double CUSUM charts were generated to assess the systematic errors for each determinant.

RESULTS

The LC-CUSUM charts revealed that different numbers of scans are required for different examiners to achieve competence in estimating birth weight. AC and FL deviated most significantly from expected values (P < 0.05). The double CUSUM charts revealed exact periods of systematic errors in the measurement of biometry determinants, clearly reflecting errors of fetal weight estimation.

CONCLUSIONS

The use of CUSUM techniques in the analysis of sonographic data allows observation of the development of an examiner's skill and maintenance of competence. The CUSUM technique not only allows the reasons for impaired fetal weight estimation to be revealed but also allows determination of the exact time when inaccurate measurements start to occur. We suggest that CUSUM charts should be implemented in routine clinical practice as a measure of objective quality evaluation of sonographic fetal biometry.

Sonographic prediction of macrosomia cannot be improved by combination with pregnancy-specific characteristics

OBJECTIVE

To evaluate the predictive value of a combination of sonographic, clinical and demographic data for detecting fetal macrosomia compared to ultrasound fetal weight estimation alone.

METHODS

Retrospective cohort data were obtained from 1062 pregnancies in an unselected population. Estimated fetal sonographic weight was obtained within the last week prior to delivery. Two different combination models-published by Mazouni et al. and Nahum and Stanislaw-were employed to predict the presence of macrosomia at birth in these infants. Receiver-operating characteristics (ROC) curves were generated to compare the prediction of macrosomia when using different observation methods and sensitivity, specificity, positive predictive value, negative predictive value (NPV) and accuracy were calculated.

RESULTS

Macrosomia (birth weight >or= 4000 g) was present in 135/1062 (12.7%) newborns. ROC curve analysis revealed the prediction of macrosomia using ultrasound alone to be significantly superior to the combined method of Mazouni et al. (area under the curve (AUC) 0.922, 95% CI 0.902-0.943 vs. 0.747, 95% CI 0.700-0.794, respectively; P < 0.0005), whereas the performance of the Nahum and Stanislaw equation was similar but not superior to ultrasound alone (AUC 0.895, 95% CI 0.839-0.950 vs. 0.912, 95% CI 0.867-0.958, respectively; P > 0.05). The accuracy of macrosomia prediction was similar for ultrasound alone and the Nahum and Stanislaw equation (approximately 90%), whereas the nomogram of Mazouni et al. reached only 51.7% accuracy (using a probability cut-off level of 50%). The NPV was found to be over 90% for all methods.

CONCLUSIONS

Combination of sonographic estimates with clinical and demographic variables does not improve the prediction of macrosomia at delivery in comparison with a routine ultrasound scan within a week before delivery, at least in unselected populations.

Outcome of fetal renal pelvic dilatation diagnosed during the third trimester

OBJECTIVES

The aim of this study was to evaluate renal function and the need for postnatal treatment--antibiotic therapy and/or surgery--in relation to the grade of fetal renal pelvic dilatation (RPD) found on third-trimester ultrasound examination.

METHODS

The retrospective study included 78 children, born between 1995 and 2000, with 115 dilated fetal renal pelvic units. The children were allocated to three groups based on pelvic anteroposterior diameter (APD) detected on third-trimester ultrasound: APDs of 7-9.9 mm, 10-14.9 mm and > or = 15 mm were classified as mild dilatation, moderate hydronephrosis and severe hydronephrosis, respectively. Renal function was assessed by scintigraphy.

RESULTS

None of the 20 children with mild dilatation experienced a urinary tract infection (UTI) or underwent surgery; two had associated renal or urinary tract abnormalities. In contrast, five out of 22 (23%) children with moderate hydronephrosis and 23 out of 36 (64%) with severe hydronephrosis had either a UTI or required surgery (P < 0.001); associated abnormalities were also more common (6 out of 22 and 15 out of 36, respectively). There was no significant correlation between the grade of antenatal RPD and postnatal ipsilateral renal function.

CONCLUSIONS

The need for postnatal treatment increased significantly with the grade of antenatal RPD. Children with antenatal mild dilatation were discharged early from follow-up whereas those with moderate and severe fetal hydronephrosis needed close follow-up by a multidisciplinary team.

Prenatal ultrasound findings in a fetus with congenital contractural arachnodactyly

Congenital contractural arachnodactyly (CCA) or Beals-Hecht syndrome is an autosomal dominant disorder caused by mutations in the fibrillin-2 (FBN2) gene. The principal features of CCA are a marfanoid habitus, multiple congenital contractures, camptodactyly, arachnodactyly, kyphoscoliosis, muscular hypoplasia, and external ear malformations. Our case is the first that shows typical sonographic signs in a fetus at 25 weeks' gestation with molecular genetically verified CCA in a large family with many members affected over four generations. This demonstrates that CCA can be detected prenatally by non-invasive ultrasonography. The importance of confirmation of CCA by means of DNA sequence analysis of the FBN2 gene is stressed.

Marked splenomegaly in fetal cytomegalovirus infection: detection supported by three-dimensional power Doppler ultrasound

An enlarged fetal spleen can be associated with fetal infection, anemia and different syndromes but its prenatal diagnosis is rare. We report on a diagnosis of splenomegaly at 32 weeks' gestation in a fetus which was found to be affected by cytomegalovirus infection. An enlarged spleen was suspected when the stomach was found to be displaced anteriorly and medially and the diagnosis was supported on visualization of the splenic vessels by color and three-dimensional power Doppler ultrasound. The patient had been referred because of fetal growth restriction and intracerebral anomalies and the additional finding of splenomegaly was highly suspicious for cytomegalovirus infection. This was confirmed by positive maternal serology and by neonatal virus excretion in urine. Retrospectively, examination of stored blood samples from 9 and 23 weeks' gestation revealed an early cytomegalovirus infection. Antenatal and neonatal magnetic resonance imaging examinations showed microcephaly, lissencephaly and the presence of microcalcifications. At the age of 9 months, the child suffers from severe neurological impairment and blindness due to severe optical atrophy. This case emphasizes that color Doppler and three-dimensional power Doppler ultrasound can facilitate the antenatal diagnosis of splenomegaly and can help to delineate the spleen from the similar-looking neighboring liver.

Diagnosis of skeletal dysplasia by multidisciplinary assessment: a report of two cases of thanatophoric dysplasia

Skeletal dysplasias, a heterogeneous group of bone growth disorders, can be detected by routine prenatal ultrasound examination. As it is difficult to make a specific diagnosis, prediction of prognosis is of importance for obstetric management. In order to specify diagnosis, radiological, pathological and molecular genetic examination are often required. Our report describes two cases of thanatophoric dysplasia with different fetal sonographic findings. The classical classification of type I and II seems to be ambiguous as, in both cases, the same mutation in the fibroblast growth factor receptor 3 gene was found. The importance of comprehensive multidisciplinary assessment is emphasized.

Chronic tubulointerstitial nephropathy in six okapis (Okapia johnstoni)

Renal tubular atrophy with conical and medullary interstitial fibrosis with severe thickening of the basement membranes of atrophic tubules was found in six okapis (Okapia johnstoni). Focal glomerular atrophy, probably secondary to ischemic collapse of the glomerular capillary tuft, was also observed. Although the etiologies and pathogeneses of these nephropathies are unclear, primary damage of the tubular epithelium appears to be the most likely cause, and toxicity from ingested plant material, possibly willow (Salix sp.), is a possibility.

[Methods and consequences of pre-natal diagnostics]

Prenatal medicine is a young subdiscipline of modern obstetrics. It applies diagnostic methods like amniocentesis, chorionic villus sampling and foetal blood sampling. The latter is not only a diagnostic procedure but opens access to the foetal circulation and therefore to foetal therapy. Aim of prenatal diagnostic procedures is the most exact diagnosis of the foetal condition as basis for rational obstetrical decisions. If a foetal disease is diagnosed, decisions are in principal similar to the postnatal situation, but therapeutic options are reduced. Decision making in prenatal medicine always has to take maternal and foetal interests into account. We have to consider that not the methods but the intention and actions of the persons involved may cause an ethical dilemma. It must be our aim to use the methods of prenatal medicine with the utmost responsibility.

Volume sonography of the pelvic floor in nulliparous women and after elective cesarean section

OBJECTIVE

To describe the sonographic appearance of the pelvic floor which has not been stressed by forces of labor or vaginal delivery in pregnant women and after childbirth.

SUBJECTS AND METHODS

In a prospective observational study 14 nulliparous women during first trimester pregnancy and 26 primiparous women after elective cesarean were examined within the first week postpartum. The integrity of the internal anal sphincter expressed as the ratio between the anterior and the posterior internal anal sphincter muscle thickness (a/p-ratio), asymmetry of the levator ani muscle and the paraurethral fixation of the lateral vaginal edges at the arcus tendineus were assessed using volume sonography.

RESULTS

The a/p-ratio in nulliparous women was significantly higher (p<0.01) than after elective cesarean section. Asymmetry of the levator ani muscle did not differ between both groups but was more frequently in the nulliparous patients with an odds-ratio of 1.16 (CI 0.74-1.82). In both groups of women the paraurethral fixation of the lateral vaginal edges were above the suburethral level of the vagina.

CONCLUSIONS

This study gives sonographic features of the pelvic floor in nulliparous women and in primigravidae after elective cesarean section. Data from the post-cesarean group can serve as reference values for further studies evaluating pelvic floor damage after various modi of vaginal delivery.

Reference values of fetal peak systolic blood flow velocity in the middle cerebral artery at 19-40 weeks of gestation

OBJECTIVES

The objectives of this prospective study were (i) to establish new reference values of peak systolic blood flow velocity measurement in the fetal middle cerebral artery (MCA-PSV) following validated methodological guidelines and (ii) to develop a method to calculate Z-scores of MCA-PSV.

PATIENTS AND METHODS

Cross-sectional data were obtained from 331 pregnant women between 19 and 40 weeks' gestation. Reference ranges for MCA-PSV were constructed and for each measurement linear regression models were fitted separately to the mean and standard deviations (SD) as a function of gestational age. An application to calculate Z-scores was developed. A comparison was made between the reference ranges produced in our study and those of a previous one.

RESULTS

A new chart, table of centiles and regression equations of MCA-PSV are presented. Comparison of our reference ranges with ones produced in a previous study showed similar 5th centile values. However, the values for the 50th and 95th centiles between 19 and 28 gestational weeks were lower in our study.

CONCLUSIONS

We have constructed reference ranges for MCA-PSV which, because they are derived from a larger number of examinations in the 15-20-week period and because the methodological flaws of the previously published study have been eliminated, we consider to be more accurate and therefore more useful for clinical practice.

Ultrafast MR imaging of the fetus

OBJECTIVE

We examined the capability of ultrafast single-shot fast spin-echo imaging to assess different fetal organ systems compared with prenatal sonography, using autopsy or postpartum imaging as a standard of reference.

SUBJECTS AND METHODS

Thirty women with complicated pregnancies (mean age of gestation, 190 +/- 54 days) underwent T2-weighted ultrafast MR imaging. MR images were analyzed with regard to diagnostic confidence in assessing abnormalities of fetal organ systems, and data were correlated with postpartum findings or necropsy. Results were compared with those of prenatal sonography.

RESULTS

Using receiver operating characteristic curve analysis, diagnostic confidence of MR imaging was best for assessing the brain (area under the curve [Az] = 0.96) and spinal canal (Az = 1.0), uteroplacental unit (Az = 0.93), and lungs (Az = 0.91). Results for the heart (Az = 0.63) and extremities (Az = 0.77) were significantly lower than that of other organs (p < 0.001). Diagnostic accuracy increased with gestational age. No statistically significant difference between sonography and MR imaging was found for the detection of abnormality in any organ system. In three fetuses, MR imaging was superior to sonography in characterizing cerebral abnormalities. MR imaging was inferior to sonography in characterizing abnormalities of the heart and extremities.

CONCLUSION

Our results indicate that ultrafast MR imaging can be used for in vivo fetal imaging, especially in assessing cerebral abnormalities. However, MR imaging should be restricted to situations in which sonographic findings are ambiguous or impaired.

Dandy-walker malformation: prenatal diagnosis and outcome

Prenatal ultrasound identified Dandy-Walker malformation (DWM) in ten singleton pregnancies with concurrent central nervous system (CNS) anomalies and extra-CNS anomalies in eight cases. DWM was confirmed by postnatal magnetic resonance imaging (MRI) or pathological examination in nine cases. Karyotypes were normal in the seven infants tested. Postnatal neurological and developmental testing in the five survivors showed a spectrum of clinical outcome from minor defects to severe handicap. Postnatal investigation also disclosed additional CNS and extra-CNS findings not detected on ultrasound, as did autopsy in the other five infants. However, ultrasound diagnosis of DWM is accurate and is an indication for exhaustive screening for concurrent anomalies both within and outside the CNS and in chromosome structure and number, as the prognosis is heavily dependent on associated malformations and karyotype.

Prenatal diagnosis of mosaicism for a del(22)(q13)

A case of prenatally detected mosaicism for a del(22)(q13) is reported. CVS was performed because of abnormal fetal ultrasound findings: cystic 'tumour' in the fetal neck and the upper thoracic aperture. Karyotypes from chorionic villi were suspicious of an aberration concerning the long arm of one chromosome 22. FISH analysis demonstrated mosaicism for a distal 22q deletion in fetal fibroblasts. The deletion was postnatally confirmed by FISH with a chromosome-specific 22q probe. The 'tumour' on autopsy turned out to be cystic thymic tissue. Apart from this, no other obvious fetal anomalies were found.

Prenatal ultrasound diagnosis of a femur-fibula-ulna complex during the first half of pregnancy

A case of fetal femur-fibula-ulna (FFU) complex diagnosed by ultrasound is presented. Ultrasonographic features of a fetus displaying bilateral femoral hypoplasia, aplasia of the right forearm and the right hand, ray defects of the left hand are described. The importance of an early diagnosis of this malformation is emphasized with respect to parental counselling concerning prognosis and further prenatal management.

[LSD and cannabis abuse in early pregnancy with good perinatal outcome. Case report and review of the literature]

This is a case report of a 27-year-old patient who had smoked a joint (cannabis) and 20 cigarettes (tobacco) daily up to the time of a positive pregnancy test at 7 4/7 weeks (p.c.). On day 20 p.c. she had an LSD minitrip. There are reports of chromosome aberrations in in vitro animal studies with LSD. In humans the main consequences are malformations of the fetal extremities and dysplasias of the eye. In both animals and humans cannabis causes changes in dopaminergic activity. Our recommendation was to continue the pregnancy, but to monitor it closely. The patient had a spontaneous term delivery-a lively boy with weight between the 5th and the 50th percentile, length between the 50th and the 90th percentile, normal umbilical arterial and venous pH values, and Apgar scores 7/9/10. There were no visible abnormalities, and behaviour was normal. If it is suspected that a pregnant patient consumes LSD, dysplasias of the fetal skeleton and eye should be checked for. With respect to LSD and to cannabis, too, the intellectual development of the child should be closely followed.

Fetal ultrasound biometry: 2. Abdomen and femur length reference values

OBJECTIVE

To create reliable reference ranges and calculate Z scores for fetal abdomen and femur ultrasound biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy.

DESIGN

A prospective, cross-sectional study.

SETTING

Obstetric clinics (outpatient and delivery units) at the University Hospital of Zurich.

SAMPLE

The study data were obtained from 6557 pregnant women.

METHODS

Only the first ultrasound examination between 12 and 42 weeks of each fetus with certainly established gestational age was used for analysis. No exclusions were made on the grounds of small-for-date birthweight, prematurity or other events several weeks after the examination. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each parameter.

RESULTS

A total of 5807 mean abdominal diameters and abdominal circumferences were derived from fetal transverse and anterio-posterior fetal abdominal diameter measurements. Fetal femur length was measured in 5860 instances. The charts, tables and regression formulae of the biometrical measurements are presented. A comparison of our charts with others showed no significant difference. Only Merz's centiles for abdominal biometry were lower and for femur length higher than ours. An application to calculate Z scores was developed using Excel (Microsoft Corporation, USA); the macros are presented in detail in the Figure 6 footnote.

CONCLUSIONS

We have presented centile charts, tables and formulae for fetal abdominal diameter and circumference and femur length derived from a large and minimally selected sample size in a carefully designed cross-sectional study. Complete tables and regression formulae to calculate reference ranges and Z scores are presented to use in computer-aided evaluation of fetal ultrasound biometry.

Fetal ultrasound biometry: 1. Head reference values

OBJECTIVE

To create reliable reference ranges and calculate Z scores for fetal head ultrasound biometry using a large sample size which is evenly distributed from 12 to 42 weeks of pregnancy.

DESIGN

A prospective, cross-sectional study.

SETTING

Obstetric clinics (outpatient and delivery units) at the University Hospital of Zurich.

SAMPLE

The study data were obtained from 6557 pregnant women.

METHODS

Only the first ultrasound examination between 12 and 42 weeks of each fetus with exactly established gestational age was used for analysis. No exclusions were made on the grounds of small-for-date birthweight, prematurity or other events several weeks after the examination. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each parameter.

RESULTS

A total of 6217 fetal head biparietal diameters and 5510 occipito-frontal diameters were measured. Both head circumference and cephalic index were derived in 5462 cases where both biparietal diameter and occipito-frontal diameter could be measured on the same fetus. The centile charts, tables and regression formulae for biparietal and occipito-frontal diameters, head circumference and cephalic index are presented. An application to calculate Z scores was developed using Excel (Microsoft Corporation, USA) and macros are presented in detail in the Figure 8 footnote. The comparison of our charts with those of the two most recent studies revealed almost no differences in biparietal diameter centiles. In one publication, occipito-frontal diameter charts, and in another, head circumference charts were different from the current study.

CONCLUSIONS

We have presented centile charts, tables and regression formulae for fetal head ultrasound biometry derived from a large and minimally selected sample size in a carefully designed cross-sectional study. Complete tables and regression formulae to calculate reference ranges and Z scores are presented for use in computer-aided evaluation of fetal ultrasound biometry.

Use of 3D ultrasound as a new approach to assess obstetrical trauma to the pelvic floor

OBJECTIVE

To determine whether 3D ultrasound examination of pelvic floor anatomy after vaginal delivery allows detection of childbirth trauma.

STUDY DESIGN

Pelvic floor anatomy was examined in 16 women during the puerperium with a 3D transrectal ultrasound probe. Images were acquired via the vaginal route for the assessment of anal morphology and the transrectal route to determine paravaginal fixation. Images of the anterior pelvic floor were calculated from the information stored in the volume block. Paravaginal defect is defined as a descent of the lateral vaginal wall below the suburethral vagina, whereas sphincter defects are characterised as thinning, or as gap formation of the anterior part of the internal anal sphincter.

RESULTS

This new approach allowed the examination of a horizontal plane through the urethra and the periurethral tissue which is inaccessible with 2D ultrasound techniques. Morphology of the normal and traumatised anal sphincter could be demonstrated using reference planes perpendicular to the anal canal.

CONCLUSIONS

Whereas in the past, defects of the vaginal attachment to the pelvic side wall could not be examined sonographically, 3D ultrasound can now be used to examine pelvic floor anatomy and to detect changes associated with trauma to the pelvic floor following vaginal delivery.

Prenatal diagnosis of fetal malformations by ultrafast magnetic resonance imaging

Prenatal ultrasonography is the primary imaging modality in pregnancy as it allows direct real-time fetal examination. Antenatal magnetic resonance imaging (MRI) has so far been of limited clinical value owing to poor image quality. This was due to the long acquisition times that were needed to achieve a high enough spatial resolution for assessment of the small fetal anatomic structures resulting in severe motion artefacts. This problem has now been overcome by recent technical improvements. We present a case of fetal malformation (MURCS association), where an ultrafast T2-weighted RARE sequence (single shot fast spin echo sequence) provided images of excellent quality, which led to the correct antenatal diagnosis. MRI using this sequence can now be used for prenatal diagnosis and is thus likely to become an important adjunct to ultrasonography, especially in cases in which ultrasound findings are unclear of sonographic images are impaired by maternal obesity or oligohydramnios.

Pulsatility index in the fetal anterior tibial artery during the second half of normal pregnancy

The objective of this prospective study was to establish reference values for the pulsatility index in the fetal anterior tibial artery during the second half of pregnancy. Pulsed Doppler waveform analysis of 203 fetuses at 23-42 weeks of pregnancy was performed, each fetus being examined just once. There were neither fetal nor maternal complications detectable at the time of the examination. In the first 14 fetuses from which recordings were taken, Doppler examination was performed on both fetal legs in order to evaluate systematic differences between the right and left legs. Intraobserver variability was analyzed by repetition of the measurements by the same examiner in the first 130 cases. There was no difference between right and left tibial circulation. The repeatability coefficient, defined as the 95% range for the difference in two repeat measurements, was 1.08. The pulsatility index of the anterior tibial artery (50th centile) increased slightly from 3.29 at 23 weeks of pregnancy to 4.09 at 42 weeks. The 5th and 95th centiles were calculated, as was the 95% confidence interval of the 5th and 95th centiles. Examination of the fetal peripheral circulation during the second half of pregnancy is possible with a high degree of precision. Whether there are changes in peripheral arterial circulation in compromised fetuses remains to be evaluated.

[PARS--a software program for pathologic anatomic diagnosis of wild animals]

A computer programme (PARS) was designed for the collection of Pathological-Anatomical References of the Institute for Zoo Biology and Wildlife Research. We systemized more than 40,000 postmortem cases in order to develop a data bank for wild animal pathology. The PARS-programme was designed on the basis of PARADOX 7 for WINDOWS. As a netwoking programme with a central server it offers direct access to the data of the IZW case documentation for all scientists. In order to minimize desk work, the programme contains tables of zoological systemic (amphibians, reptiles, birds and mammals) as well as tables for systemic assignment (bacteria, viruses, fungi, protozoa, helminths and arthropods) for most common species. The records and findings of the necropsies can be printed immediately.

Successful treatment of fetal megavesica in the first half of pregnancy

OBJECTIVE

Our goal was to assess fetal kidney function in fetuses with megavesica diagnosed during the first half of pregnancy before treatment.

STUDY DESIGN

In a prospective interventional study 9 fetuses with megavesica diagnosed during the first half of pregnancy underwent vesicocentesis. Fetal urine biochemical markers (urine electrolytes, osmolarity, and beta 2-microglobulins) were determined after diagnostic vesicocentesis of the fetal megavesica.

RESULTS

Surprisingly, in four fetuses who underwent sampling at 13 to 18 postmenstrual weeks, vesicocentesis proved both diagnostic and therapeutic. Pregnancy proceeded with normal amniotic fluid volume, a normal-sized urinary bladder with normal dynamics, and normal postnatal renal function. A fifth fetus had trisomy 18. In three of the remaining four fetuses in whom sampling was performed at 16 to 20 postmenstrual weeks, biochemical markers indicated a poor prognosis. In the remaining fetus marginal results of biochemical studies prompted intrauterine treatment, but death from respiratory problems ensued after premature delivery at 31 weeks.

CONCLUSIONS

Fetal megavesica in the first half of pregnancy is an indication for an immediate diagnostic vesicocentesis. This is the first report emphasizing early diagnosis of fetal megavesica with subsequent fetal vesicocentesis and demonstrating that this minimally invasive procedure can be life-saving if performed in early pregnancy.

Reference resistance indices of the umbilical, fetal middle cerebral and uterine arteries at 24-42 weeks of gestation

The objective of this cross-sectional study was to construct new reference ranges for Doppler flow velocity waveform resistance indices for the fetal umbilical artery, middle cerebral artery, placental and non-placental uterine arteries and the placentocerebral ratio in a large and minimally selected population attending a single clinic. Study design and data analysis adhered to a number of stringent and validated methodological recommendations derived both from the recent literature and from a review of earlier publications in this field. The final database comprised initial routine Doppler velocimetry at 24-42 weeks' gestation in 1675 pregnancies. Separate regression models were fitted to estimate the mean and standard deviation at each gestational age for each vessel. New charts, centile tables and regression equations are presented for the resistance indices of the fetal umbilical artery, middle cerebral artery, placental and non-placental uterine arteries and the mean of both uterine arteries and for the placentocerebral ratio.

Lethal multiple pterygium syndrome: suggestion for a consistent pathological workup and review of reported cases

We report on 2 brothers with lethal multiple pterygium syndrome (LMPS) born to non-consanguineous parents as late spontaneous abortions. Both fetuses presented with massive nuchal edema, and facial anomalies including cleft palate and broad ribs. Apparently, several subgroups of LMPS exist. Differentiation is difficult, as there is no consistent agreement on a workup protocol for autopsies. We compared the findings in the literature on cases with LMPS, and we suggest a standardized workup as an initial step for more efficient differentiation between various subgroups.

Prenatal diagnosis in Switzerland

Switzerland, with a population of slightly over 7 million, has about 83,000 births per year. There is no comprehensive national registry for prenatal diagnosis (PND) or congenital malformations. Health care is largely organised within each of the 23 countries. Whereas ultrasound screening is available to all pregnant women, the availability of other types of PND is largely determined by proximity to the university medical centres or specialised clinics. Maternal biochemical serum screening is offered by some 15-20 laboratories, and cytogenetic analyses are performed in 8. DNA-based diagnosis is essentially limited to the medical genetics departments/divisions of the 5 university medical schools. It can be estimated that slightly over 10% of gestations are monitored by invasive prenatal diagnostic techniques. The greatest challenge for the future will be the training of the medical and paramedical personnel necessary for the current and future pre- and postnatal diagnostic testing.

[Obstetric ultrasonic studies in clinical practice]

Routine ultrasound screening during pregnancy is being debated. The paper presents the aims of a three-step ultrasound screening during pregnancy care. These are exact dating of the pregnancy, detection and classification of multiple pregnancies and the detection of fetal malformations. In order to achieve these goals, we describe these three examinations. In the Cochrane Database, the efficiency of routine ultrasound screening during pregnancy is presented. Consequences of pregnancy care without routine ultrasound examinations are discussed.

Diaphragmatic defects, limb deficiencies, and ossification defects of the skull: a distinctive malformation syndrome

We report on prenatal and postnatal findings in 4 consecutive fetuses with a pattern of severe congenital anomalies who were born to a healthy nonconsanguineous couple. The spectrum of malformations includes diaphragmatic defects, hypoplastic lungs, omphalocele, limb deficiencies, syndactyly of toes, and ossification defects of the skull. This specific spectrum of anomalies is not fully compatible with that of any established syndrome. No prenatal exposure to any possible teratogen was found. Family history is suggestive for autosomal recessive inheritance, even though germ-line mosaicism in one of the parents cannot completely be excluded.

Prenatal sonographic diagnosis of autosomal recessive polycystic kidney disease (ARPKD) during the early second trimester

Autosomal recessive polycystic kidney disease (ARPKD) is a rare hereditary disease with a high neonatal mortality. Currently, prenatal diagnosis is possible only during the second half of pregnancy, when bilaterally enlarged, echogenic kidneys are visible by ultrasound. We describe a case in which a diagnosis of ARPKD was sought in the first half of pregnancy. High-resolution ultrasonography revealed echogenic, normal-sized kidneys at 15 + 4 weeks. Microsatellite DNA analysis of a chorionic villus sample, parental blood, and blood of an affected sibling showed that the fetus had the maternal haplotype and a recombination of the paternal haplotype. Thus, no distinction between homo- and heterozygosity for the ARPKD mutation in the fetus was possible. A further ultrasound examination at 19 + 4 weeks confirmed the previous results, indicating that the fetus was likely to be affected. After termination of the pregnancy, the diagnosis was confirmed on microscopic examination.

A glycine 375-to-cysteine substitution in the transmembrane domain of the fibroblast growth factor receptor-3 in a newborn with achondroplasia

Achondroplasia, the most common form of chondrodysplasia, has been associated with mutations in the gene of the fibroblast growth factor receptor-3 (FGFR-3) on chromosome 4p. All 39 achondroplasia alleles studied so far carried point mutations which caused the same amino acid exchange, a substitution of glycine by arginine at position 380 (G380R) in the transmembrane domain of the receptor. We report on a newborn with achondroplasia who does not carry a G380R mutation but has a mutation causing substitution of a nearby glycine with a cysteine (G375C). This observation indicates allelic heterogeneity and confirms the role of mutations in the transmembrane domain of FGFR-3 in the pathogenesis of achondroplasia.

Estimation of gestational age by transvaginal sonographic measurement of greatest embryonic length in dated human embryos

A prospective descriptive study was carried out to establish reference values for gestational age assessment in the first trimester by measuring embryonic length in dated human embryos, by using transvaginal ultrasound. In 160 pregnant women who had undergone assisted reproductive procedures, 139 singleton embryos and 46 embryos from 21 multiple pregnancies were studied between the 35th and 98th day after the last menstrual period. Transvaginal ultrasound examination, including inspection of embryonic structures and measurement of greatest embryonic length (L), was performed in these women. Estimation of gestational age (t) by measurement of L in singletons is best described by the equation t = 35.72 + 1.082L(1)/(2) + 1.472L - 0.09749L(3)/(2). Mean 95% confidence interval and 95% prediction interval were 4.3 and 9.3 days, respectively. There was no significant change in the estimation curve when multiple measurements in singletons were taken nor when embryos from multiple pregnancies were measured. Accuracy of embryonic age estimation from a single measurement of greatest embryonic length was evaluated.

Temporomandibular joint disc replacement made by tissue-engineered growth of cartilage

OBJECTIVE

To test the effectiveness of the new technique of tissue-engineered growth of cartilage, temporomandibular joint (TMJ) disc replacements were created by seeding dissociated chondrocytes on synthetic, three-dimensional, bioresorbable polymer constructs of a predetermined anatomic shape, incubating the cell-polymer constructs in vitro, and transplanting them into test animals.

MATERIALS AND METHODS

Twelve highly porous and bioresorbable cell-transplantation devices in the shape of TMJ discs were created using biodegradable polylactid and polyglycolic acid fibers. Bovine articular cartilage was dissociated into chondrocytes and the cells were allowed to attach to the three-dimensional polymer scaffolds and multiply in vitro. After 1 week, the cell-polymer constructs were implanted subcutaneously into nude mice. The neocartilage was assessed by magnetic resonance imaging (MRI) techniques, gross inspection, histology, and biomechanical and biochemical analysis after 12 weeks.

RESULTS

All implants seeded with chondrocytes showed gross evidence of histologically organized hyaline cartilage. The scaffolds maintained their specific shape. They not only showed appropriate intrinsic stability during neomorphogenesis of cartilage in vitro and in vivo, but also seemed to guide the growth of cartilage. The presence of sulfated glycosaminoglycans was shown by aldehyde fuchsin alcian blue staining of the specimens. Type II collagen, considered to be indicative of cartilage formation, was found in the specimens tested. MRI showed signal characteristics similar to those of hyaline cartilage. Analysis of neocartilage force/displacement curves and aqueous phase compliance using a closed compression chamber suggested that the ability of the constructs to resist deformation was similar to that of native donor cartilage.

CONCLUSION

The technology of tissue-engineered growth of cartilage on individually designed scaffolds may have many applications not only in reconstructive surgery of the TMJ, but also in craniomaxillofacial, plastic, and orthopedic surgery.

Embryonic heart rate in dated human embryos

Using simultaneous B-mode and time-motion transvaginal ultrasonography we measured embryonic heart rate (EHR) in dated human embryos during the first trimester in a prospective study. In 160 pregnant women who had undergone assisted reproductive procedures, 139 singleton embryos and 46 embryos from 21 multiple pregnancies were studied between the 37th and 98th postmenstrual day. Because multiple measurements in one embryo at different ages were possible, a total of 348 measurements were taken. EHR in dated human embryos shows an increase up to 63 postmenstrual days or 22 mm greatest length. Thereafter a steady decrease of EHR was noted. Maximal EHR is reached when morphological development of the embryonic heart is completed. Furthermore, we examined 27 embryos with low EHR compared with greatest embryonic length. All of these ended in missed abortion within the embryonic period. According to our data the increase of EHR parallels the morphological development of the embryonic heart. Decline of EHR afterwards is interpreted as a functional adaption to muscular development of the heart.