Outcome of cystic hygroma in fetuses with normal karyotypes depends on associated findings.

OBJECTIVE: To determine the associated diagnostic findings which are linked with adverse fetal outcome in nuchal cystic hygroma. STUDY DESIGN: Based on a series of 32 cases, we determined the sonographic morphology of the hygroma, associated structural anomalies, karyotypes and autopsy findings. Intrauterine fetal death, spontaneous abortion and abnormal karyotypes were assigned as adverse outcome parameters. RESULTS: The mean gestational age at diagnosis was 14.4 weeks (range 10-21). There were 18 nonseptated and 14 septated hygromas. Besides hygroma, associated sonographic detectable structural anomalies were observed in 17 cases (53.1%). The greatest number of associated sonographic anomalies were hydrops (31.3%), generalised skin oedema (6.3%) and pterygium colli (6.3%). Cytogenetic analysis revealed an abnormal karyotype in 13 of 26 (50%) invasive procedures. Turner syndrome and Trisomy 18 (both 15.4%) were the most frequent cytogenetic abnormalities. Autopsy was performed in 24 cases and 16 cases (66.7%) had an associated autopsy finding to hygroma colli. The most frequent associated autopsy findings were limb and craniofacial anomalies (both 25%). Only 3 (9.4%) mothers gave birth to healthy newborns. The overall fetal adverse outcome rate was 68.8% (22 cases). CONCLUSIONS: Fetuses with NCH are at high risk for adverse outcome and detailed prenatal diagnosis including invasive procedures should be offered. According to the presented autopsy findings, to determine fetal outcome in NCH cases with normal karyotypes, detailed sonography should be concentrated beside the exclusion of fetal heart defects and existence of hydrops fetalis, on the skeletal, urogenital and craniofacial anomalies, as these might cause severe morbidity.

[Reverse flow in fetal vessels and perinatal events]. / Reverse Flow in den fetalen Gefässen - Klinische Bedeutung und perinatale Auffälligkeiten.

UNLABELLED: BACKGROUND/PATIENTS: A reverse flow in the umbilical artery and/or fetal aorta is associated with a higher perinatal and neonatal mortality. 30 fetuses showed a reverse flow using pulsed wave Doppler sonography (group I). A matched-pair control group including 30 fetuses with the same gestational age as well as a normal Doppler flow pattern in the umbilical artery and/or fetal aorta was taken for comparison (group II). RESULTS: In the group with reverse flow the rates of pregnancies with pre-eclampsia (n = 19/30, p < 0.0001), intrauterine growth retardation (n = 25/30, p < 0.0001), oligohydramnios (n = 21/30, p < 0.0001) and nicotine abuse (n = 15/30, p < 0.01) were significantly higher compared to the control group. Postnatal data showed significantly lower pH values in group I (p < 0.01). 40 % of the fetuses with reverse flow died in utero whereas in 67 % the reverse flow was accompanied by an insufficiency of the placenta (IUGR, oligohydramnios, histopathological abnormalities of the placenta). None of the fetuses in the control group died in utero. The incidence of IUGR (< 5ht percentile) was 83 % in group I but only 3 % in group II. The perinatal and overall mortality (including neonatal mortality 7 - 28 days after birth) amounted to 27 % and 53 % in group I, respectively, compared to 3 % and 0 % in the control group (p < 0.001). In addition cerebral anomalies could be found by ultrasound in 50 % of the neonates who presented a reverse flow prenatally. In 28 % of the surviving newborns an intracerebral hemorrhage (ICH) could be detected. None of the newborns of group II developed an ICH. CONCLUSIONS: Pregnancies with a reverse flow in the umbilical artery and/or fetal aorta have to be considered as a high risk group with a poor prognosis. The reverse flow is mainly caused by chronic placental insufficiency with IUGR. With respect to the further neuromotor development the incidence and severity of cerebral lesions in affected fetuses should be considered when discussing the perinatal situation with the parents.

[Infections in pregnancy]. / Ringelröteln--Zytomegalievirus-Infektion--Varizellen. Rechtzeitiges Erkennen kann Mutter und Kind schützen.

Infections of the mother-to-be continue to be a problem for a successful birth. However, on the basis of the case history, special examination methods (infection serology, pathogen determination) and the noninvasive and invasive prenatal diagnostic work-up, the risks for the fetus can be much better assessed than 10-15 years ago. This avoids unnecessary terminations of the pregnancy, better counseling of the parents-to-be, appropriate monitoring of the fetus, and improved treatment of mother and child during the pregnancy, or of the neonate. To ensure optimal care of mother and fetus, the family doctor, too, should be familiar with the major relevant infections, their symptoms, prophylactic options and treatment. As a general rule, cooperation with midwives, obstetricians and/or obstetric centers, specialist laboratories and neonatologists is essential.

Fetomaternal Doppler sonography nomograms.

PURPOSE: To constitute Doppler flow velocity nomograms for use in obstetric clinics and to analyse the technical infrastructure of constructing Doppler sonography nomograms for clinical use. METHODS: On a cross-sectional study plan basis 602 flow results of 370 pregnant women were used. Pregnancy gestational ages were confirmed with an early sonogram prior to the 14th gestational week. Patients in whom primary section for placental insufficiency had to be done, who had pathological fetal heart rate monitoring, signs of intrauterine asphyxia, multiple pregnancy or a fetal anomaly were excluded. Every two gestational weeks patients were grouped and for these groups the 5th, 10th, 50th, 90th and 95th percentiles were calculated to represent the umbilical artery, fetal aorta, middle cerebral artery (MCA) and uterine artery S/D ratio, resistence index (RI) and pulsatility index (PI) Doppler flow velocity nomograms. RESULTS: In normal pregnancies, after the 22nd-24th gestational week, the uteroplacental flow velocities were constant, but at the fetal vessels there were changes in velocity waveforms after this period. With advancing gestation in the third trimester, umbilical artery and middle cerebral artery impedance was lower and the resistance in the descending fetal aorta remained nearly constant. CONCLUSION: With growing gestational age the Doppler velocity forms change. In fact because of this, for Doppler velocity studies and to differentiate between normal and abnormal pregnancy status, nomograms adapted to gestational age should be used. For practical use in different obstetrics clinics, we are presenting our Doppler velocity norm-curves.

Prenatal diagnosis of sacrococcygeal teratoma: a review of cases between 1993 and 2000.

Sacrococcygeal teratoma is the most common fetal neoplasm with a reported incidence of 1 in 30,000 to 40,000 births. Affected fetuses carry a high perinatal mortality and morbidity. The aim of this retrospective study was to assess prenatal sonographic aspects and pathological details of our cases with sacroccocygeal teratoma. Over the last seven years we identified six cases by retrospective chart review in our institution. Four fetuses were electively aborted, in two of these four fetuses the diagnosis was made before the 16th week of gestation. Two caesarean sections were performed at 35 + 5 and 37 + 0 weeks of gestation, respectively. In those two cases the diagnosis was only made in the late second and third trimester. No case of neonatal mortality occurred. In one of the two resected sacroccocygeal teratomas potential malignancy was diagnosed. A multidisciplinary approach seems advisible for optimal perinatal management.

Significance of high and normal neonatal nucleated red blood cell count in small-for-gestational-age newborns.

The objective of this study was to evaluate the obstetrical and neonatal outcome in small-for-gestational age (SGA) and appropriate-for-gestational-age (AGA) fetuses with normal and elevated neonatal nucleated red blood cell counts. Therefore the nucleated red blood cell count was assessed immediately after birth in 906 neonates delivered at our institution and the perinatal and neonatal data were compared. Postnatally, infants were classified as SGA if they had a birth weight for given gestational age below the 10th percentile. Neonates were allocated to four groups according to their nucleated red blood cell count: SGA neonates with normal and high nucleated red blood cell count and appropriate-for-gestational-age newborns (AGA) with normal and high nucleated red blood cell count. Statistical analysis included the Mann-Whitney U-Test, Student's t-test, chi2 analysis of variance and stepwise regression analysis. SGA newborns with high nucleated red blood cell count had a significantly lower birth weight, a lower gestational age at delivery, lower arterial and venous pH values, lower Apgar scores at 1 min, 5 min and 10 min as well as lower base excess values compared to the other groups. They had to be transferred significantly more often and stayed longer in the neonatal intensive care unit. Three cases of intraventricular hemorrhage, four cases of necrotizing enterocolotis and two neonatal deaths occurred all in the SGA group with high neonatal nucleated red blood cell counts. Neonatal outcomes of SGA and AGA newborns with normal nucleated red blood cell counts were comparable. Our data do therefore underline the possible value of neonatal nucleated red blood cell counts to differentiate the healthy small-for-gestational age newborn from the truely growth retarded newborn.

Prenatal and perinatal aspects of a giant fetal cervicothoracal lymphangioma.

A massive cervicothoracal lymphangioma was diagnosed in a fetus at 25 weeks of gestation. On ultrasound study, the mass showed septated, cystic components and extended from the right submandibular region to the right anterolateral thoracic wall including the right axilla and right scapula. Close sonographic follow-up revealed an increase in the size of the lymphangioma without fetal hydrops. An interdisciplinary approach including a pediatric surgeon, neonatologist, perinatologist and anesthesiologist was chosen. Elective cesarean section under general anesthesia was planned at 37 + 0 weeks of gestation. Surgical correction of the lymphangioma was successfully performed on the 4th day of life. Possible differential diagnoses and the obstetrical management are presented.

Nucleated red blood cell counts in growth-restricted neonates with absent or reversed-end-diastolic umbilical artery velocity.

OBJECTIVE: To determine the effect of increasing circulatory impairment in fetuses on the neonatal nucleated red blood cell count. METHODS: Seventy-seven fetuses with suspected intrauterine growth restriction (abdominal circumference < 5th percentile), subsequent birth weight < 10th percentile for gestational age and abnormal umbilical artery Doppler flow velocity were enrolled in the study. Fetuses were assigned to the following groups on the basis of the last Doppler examination before delivery: group 1, umbilical artery S/D ratio > 2 SD above the gestational age mean, group 2, absent end-diastolic velocity in the umbilical artery, group 3, reversed end-diastolic velocity in the umbilical artery. Neonatal nucleated red blood cells were obtained from the umbilical artery within 1 min after delivery with follow-up examinations until the nucleated red blood cell count was < 5/100 white blood cells. Perinatal and neonatal data were recorded from the charts. RESULTS: Significantly higher nucleated red blood cell counts [median 144, range 9-964] with lowest birth weights [mean 932 g, range 530 g-2060 g] were detected in group 3 and in group 2 [median 65, range 2-720; mean 1049 g, range 630 g-2110 g] compared to group 1 [median 22, range 2-201; mean 1565 g, range 860 g-2780 g, p < 0.001, respectively]. The persistence of nucleated red blood cells in the neonatal circulation was prolonged in group 3 [median 5.2, range 1-13 days] compared to group 2 [median 3.9, range 1-81 and group 1 [median 1, range 0-2]. Neonates in group 3 also had decreased platelet counts, hematocrit and hemoglobin values. Cord blood gases showed a significant decrease of arterial and venous pH values in groups 2 and 3 which was accompagnied by a significant decrease in base excess values. Four neonatal deaths, three of them in the reversed-end-diastolic velocity and one in the absent end-diastolic velocity group, occurred. Stepwise regression demonstrated that absent or reversed end-diastolic flow velocities, birth weight, gestational age and arterial base excess contribute significantly to the elevation of the nucleated red blood cell counts. CONCLUSIONS: Increased nucleated red blood cell counts at birth and their longer persistance in the neonatal circulation are associated with antenatal abnormal umbilical artery Doppler studies in growth restricted fetuses. The nucleated red blood cell count might therefore become an additional valuable tool in the diagnosis of growth restricted fetuses who are metabolically compromised.

Hygroma colli cysticum: prenatal diagnosis and prognosis.

The objective of this study is to analyze the prenatal management and prognostic factors of hygroma colli cysticum by using cytogenetic tests and sonographic morphological features. All cases with hygroma colli cysticum diagnosed and managed at our Prenatal Diagnostics Unit between January 96 and September 2000 were analyzed. Sonographic morphological features were divided in two groups; nonseptated (n = 18) and septated (n = 12) hygroma colli cysticum lesions were compared with fetal karyotype results and pregnancy outcome data. Statistical analysis was performed by Chi-square test and statistical significance was defined as p <0.05. In 5 years, 30 cases with hygroma colli cysticum were identified. Cytogenetic results were obtained from 23 (76.7%) cases (four chorionic villus sampling and 19 amniocentesis). Chromosomal abnormalities were present in 13 cases (56.5%). The most common chromosomal abnormality was Turner Syndrome (four cases, 17.4%) and Trisomy 18 (four cases, 17.4%). Pregnancy outcome data were available for 29 patients. Those fetuses with septated hygroma colli cysticum tended to have a worse fetal outcome, without statistical significance (p >0.05), compared with the nonseptated hygroma colli cysticum cases (75 vs. 61.1%, respectively). Fetal hygroma colli cysticum, either septated or not, carries high risks of aneuploidies and adverse fetal outcome. Recommended management includes karyotyping and if parents decide to continue the pregnancy ultrasound scan at 20 to 22 weeks' gestation is necessary, for excluding associated anomalies. At birth, if the cystic hygroma persists, it should be noted that a respiratory difficulty can happen and a pediatrician should standby as a precaution.

Neonatal nucleated red blood cell counts: relationship to abnormal fetoplacental circulation detected by Doppler studies.

Increased neonatal nucleated red blood cell counts are thought to be related to intrauterine hypoxemia. We sought to determine the effect of increasing circulatory impairment in fetuses on the neonatal nucleated red blood cell count. One hundred thirty-four singleton pregnancies were included in the study and were allocated to 4 study groups according to Doppler findings. The systolic-to-diastolic ratios of the umbilical artery, fetal aorta, middle cerebral artery, and uterine arteries were recorded. Fetuses were assigned to the following groups on the basis of the last Doppler examination before delivery: group 1, normal systolic-to-diastolic ratios in the examined vessels; group 2, a systolic-to-diastolic ratio greater than 2 SD above the mean for gestational age in the umbilical artery or fetal aorta and no abnormal Doppler findings in the uterine arteries; group 3, systolic-to-diastolic ratios greater than 2 SD above the mean for gestational age in all examined vessels; and group 4, absence of end-diastolic velocity in the umbilical artery or fetal aorta and systolic-to-diastolic ratios greater than 2 SD above the mean for gestational age in the uterine arteries. A blood sample from the umbilical artery was obtained within 1 minute after birth, and nucleated red blood cells per 100 white blood cells were counted by light microscopy. Nucleated red blood cell counts were higher in fetuses in group 4 (median, 72.0; range, 9-720; P < .001) and group 3 (median, 38.4; range, 7-201; P < .001) than in fetuses in group 1 (median, 5.1; range, 0-20). Neonates in group 4 had significantly lower birth weights (P < .001), lower arterial and venous pH values (P < .05), and lower Apgar scores after 5 minutes (P < .01) as well as an increased likelihood of cesarean delivery because of fetal distress (P < .001). The number of fetuses in group 4 with a cord blood base deficit of less than -8 mmol/L was increased. Nucleated red blood cell counts were comparable in fetuses in group 2 (median, 5.4; range, 0-37) and group 1. In groups 1 to 3 no brain-sparing effect occurred, whereas in 15 of 21 cases in group 4 a brain-sparing effect was present. Multivariate analysis revealed that Doppler results of the umbilical artery, fetal aorta, and uterine arteries were independent determinants of neonatal nucleated red blood cell count. Increasing abnormalities seen on fetoplacental Doppler studies are associated with increasing numbers of nucleated red blood cells at birth. Given the known relationship between abnormal Doppler flow and intrauterine hypoxemia, the neonatal nucleated red blood cell count might become an additional valuable tool in the surveillance of growth-restricted fetuses.

Course and outcome of a pregnancy with a giant fetal cervical teratoma diagnosed prenatally.

We report the course and outcome of a pregnancy involving a giant fetal neck teratoma which was diagnosed at 23 weeks of gestation. Sonographic surveillance of the fetal neck revealed continuing growth of the tumor with development of polyhydramnios. Three-dimensional ultrasound provided additional detailed information on the external extent of the lesion. Color Doppler ultrasound showed intense arterial and venous flow with low resistance indices. Cesarean section under general anesthesia was planned in close cooperation with the neonatologist, pediatric surgeon and anesthesiologist because the size of the neck mass precluded vaginal delivery. Cesarean section was performed at 34 weeks of gestation following preterm rupture of the membranes. Orotracheal intubation was not successful because of compression of the airway and a tracheostomy could not be performed because of the risk of severe fetal hemorrhage from the tumor. The neonate died from respiratory insufficiency 66 min after birth.

Neonatal nucleated red blood cell counts in small-for-gestational-age fetuses: relationship to fetoplacental Doppler studies.

OBJECTIVE: To study the influence of pathologic umbilical and middle cerebral artery and uterine artery Doppler studies on the nucleated red blood cell count in small-for-gestational-age (SGA) fetuses. MATERIALS AND METHODS: Cord blood was prospectively collected during a 18-month period. 80 SGA fetuses (fetal abdominal circumference < 5th percentile) with Doppler ultrasound of the umbilical, the middle cerebral artery and both uterine arteries were enrolled in the study. SGA fetuses with normal Doppler flow velocity waveforms were allocated to group 1 (n = 23). Group 2 (n = 13) were fetuses with abnormal umbilical Doppler studies and group 3 (n = 44) were fetuses with both, pathologic umbilical and uterine artery Doppler studies. 2 fetuses in group 3 showed evidence of brain sparing, 3 fetuses presented absent-end-diastolic flow in the umbilical artery. Outcome measures included nucleated red blood cell count, Apgar scores, arterial pH and arterial base excess, venous pH, birth weight, gestational age at delivery, mode of delivery, rate of neonatal intensive care unit admission and length of stay in the neonatal intensive care unit. RESULTS: Highest nucleated red blood cell counts with lowest birth weight and gestational age were found in group 3. Decelerations of the fetal heart rate were more frequent in study group 3 and caesarean section for fetal indication was performed more often in this group. Those fetuses had to be transfered more often to the neonatal intensive care unit than fetuses of the other study groups. There was a tendency in group 3 towards lower arterial pH values and arterial base excess values. Fetuses with absent-end-diastolic flow in the umbilical artery presented highest nucleated red blood cell counts. CONCLUSION: In SGA fetuses increasing Doppler pathology seems to be correlated with increasing nucleated red blood cell count post-partum. Pathologic uterine artery flow results might have an additional impact on the number of nucleated red blood cells at birth.

Nucleated red blood cell count and doppler ultrasound in low- and high-risk pregnancies.

OBJECTIVE: The aim of this study was to evaluate the influence of circulatory deterioration in small-for-gestational-age fetuses (SGA) on the nucleated red blood cell count (NRBC). PATIENTS AND METHODS: During a 12-month period 194 patients with a complete NRBC count post-partum were enrolled in the study. Using pulsed wave colour Doppler ultrasound we recorded blood flow velocity waveforms from both uterine arteries and from the umbilical artery and/or from the fetal aorta. Patients were assigned to seven groups according to the results of the Doppler examination. Mean outcome measures were birthweight, gestational age at delivery, NRBC count, incidence of preeclampsia or SGA and need of neonatal intensive care. RESULTS: Significantly higher nucleated red blood cell counts than in all other groups were found in cases with abnormal Doppler findings in both uterine arteries and the umbilical artery and/or fetal aorta (p<0.001). These newborns had significantly lower birth weights (p<0.01, p<0.001), lower gestational age (p<0.001), an increased likelihood of caesarean section for clinical signs of fetal distress (p<0.001) and had to be transfered more frequently to the neonatal intensive care unit (p<0.01, p<0.001). CONCLUSION: Patients with abnormal Doppler velocimetry waveforms of the uterine arteries in the presence of an abnormal umbilical artery or fetal aorta Doppler findings have a high risk of prematurity, preeclampsia or delivering a small-for-gestational-age newborn. Fetal response to uteroplacental insufficiency may lead to elevated nucleated red blood cells in the fetal blood. This fact might help to discriminate the small-for-gestational-age fetus who is growth-retarded and suffers from chronic placental insufficiency from the small but healthy fetus.

The clinical significance of antenatal pathological Doppler findings in fetal middle cerebral artery compared to umbilical artery and fetal aorta.

PURPOSE: To compare the diagnostic capacity of fetal Doppler velocimetry in fetal middle cerebral artery to umbilical artery and fetal aorta to the prediction of fetal outcome. METHODS: 229 patients between 28 weeks of gestation (weeks) and 40 weeks were examined by Doppler ultrasound in relationship to complications in gestation and labor, and fetal outcome. One thousand two hundred and seventy doppler blood flow velocity waveforms in the middle cerebral artery, umbilical artery and fetal aorta were recorded. Sensitivity of these vessels with regard to the prediction of intrauterine growth retardation, rate of cesarean section, preterm delivery and new-born depression was calculated. In all Doppler measurements there were no cases with absence of end-diastolic flow. RESULTS: The differences between pathological fetal outcome were not statistically significant, but diagnostic capacity of the middle cerebral artery velocimetry with regard to the prediction of pathological fetal outcome was on average 11% below the diagnostic capacity of the fetal aorta and umbilical artery. CONCLUSION: There is no benefit in examining fetal middle cerebral artery Doppler measurements in clinical routine in patients with normal velocity waveforms in the umbilical artery and fetal aorta.

Use of linear mixed models to detect irregular fetal growth.

Ultrasonographic fetal biometry data can be used to estimate fetal weights repeatedly over time. Different types of reference bands have been presented to judge such data. But relevant aspects of an individual growth curve are not taken in to account. How can individual growth curves be used efficiently to detect irregular fetal growth? Linear mixed model analysis of a sample of 167 uncomplicated pregnancies with 304 ultrasonic measurements revealed that a random intercept model is sufficient and heterogeneity in slopes is negligible. Hence irregularity of a sequence of weights can be captured by three quantities' residual level, trend and mean squared error' for which reference ranges are derived from the fitted model. After standardization they are independently normal and chi-square distributed in the reference population. Regularity of fetal growth may then be reported in terms of level and trend either in the form of Z-scores or as percentile indices. A sample of 97 pregnancies diagnosed as cases of chronic placental insufficiency postnatally is analysed to validate the ability to detected abnormal growth. Only the mean level and slope revealed to be able to detect IUGR. MSE was not discriminative. The sensitivity of the method depends on the number and placement of observation times, which opens the possibility of a model-based cost-effectiveness analysis. The derived scores make efficient use of available information and are easily implementable into any computer based monitoring device.

Omphalocele and gastroschisis: prenatal diagnosis and peripartal management. A case analysis of the years 1989-1997 at the Department of Obstetrics and Gynecology, University of Homburg/Saar.

OBJECTIVE: The article presents a retrospective analysis (1989-1997) of the prenatal diagnosis, the course and completion of pregnancy of 26 fetuses with omphalocele and 18 fetuses with gastroschisis. SUBJECTS: 44 pregnancies with anterior fetal wall defect diagnosed by prenatal ultrasound, clinical or patho-anatomic examination between 1989 and 1997 at the Department of Obstetrics and Gynecology, University of Homburg/Saar. RESULTS: In 40 of 44 pregnancies (91%) the fetal ventral abdominal wall defect could be detected antenatally with ultrasound. Associated malformations in fetuses with omphalocele were seen in 18 cases (69%), whereas only five fetuses with gastroschisis (28%) had an associated malformation. Nineteen of 26 fetuses (73%) with omphalocele had a normal karyotype. Seven of 26 fetuses (27%) with omphalocele had an abnormal karyotype. Eleven fetuses with omphalocele were live born, three of them with minor anomalies. Ten babies with omphalocele survived. No chromosomal anomalies were detected in fetuses with gastroschisis. There were four gastrointestinal malformations and one lethal associated malformation in fetuses with gastroschisis. There were 15 live born babies with gastroschisis, all of whom have survived. In 20 of 44 cases (45%) with ventral abdominal wall defect oligohydramnios could be detected by ultrasound. In 28 of 44 cases (64%) we found fetal growth retardation <10th percentile for gestational age. CONCLUSION: In case of a fetal ventral abdominal wall defect, the detection and appropriate classification of associated fetal anomalies is of great importance for the further course of pregnancy. Fetal karyotyping should be offered in case of a fetal abdominal wall defect. Early and close prenatal consultation of the neonatologist and the pediatric surgeon will favorably influence the perinatal outcome.

Maternal and neonatal outcome in a monochorionic twin pregnancy complicated by single intrauterine demise.

Single fetal death in monochorionic pregnancies is believed to be associated with increased risk of perinatal morbidity and mortality for the living twin and risk of coagulopathy affecting the mother. In this report we present a case of single intrauterine death in a monochorionic twin gestation diagnosed in the 28th week of pregnancy.

[Behavior of fetal position in the 2d half of pregnancy in labor with breech and vertex presentations]. / Das fetale Lageverhalten in der zweiten Schwangerschaftshälfte bei Geburten aus Beckenendlage und Schädellage.

In a retrospective analysis, presentation behavior during pregnancy of 501 infants with breech presentation at birth was compared with that of a control population (n = 520) with vertex presentation at birth. Since the fetus usually changes position frequently during the sonographic examination prior to the 20th week of pregnancy, and since its presentation behavior is generally unstable, presentation of the fetus was only determined sonographically from this point onward. In both populations it was found in 40% of the cases that the fetus remained in either breech or vertex presentation up to birth; and in both populations there was one change of position to the definitive presentation at birth in 44% of the cases (before the 33rd week of pregnancy in 95%). Seventeen percent of the infants born from breech presentation and 15% of those born from vertex presentation changed position several times during pregnancy. The stability of presentation behavior during pregnancy of infants with breech presentation at birth was similar to that of infants with vertex presentation. At about the 32nd week of pregnancy, 90% of the fetuses in both breech and vertex presentation had assumed their final presentation prior to birth. Even when breech presentation is found between the 33rd and 36th week of pregnancy there is still a 54% probability of a change to vertex presentation at birth. In contrast, the probability of the fetus turning from vertex to breech presentation at birth in this period of pregnancy is only 0.4%.