Harald Abele

Performance of 36 Different Weight Estimation Formulae in Fetuses with Macrosomia

Introduction: The aim of this retrospective clinical study was to compare the accuracy of 36 commonly used weight estimation formulae in macrosomic fetuses. Material and Methods: Ultrasound estimation of fetal weight (FW) was carried out within 7 days up to delivery in 350 singleton fetuses with a birth weight (BW) of ≧4,000 g. The accuracy of the different formulae for FW estimation was compared by, firstly, the mean percentage (MPE) and mean absolute percentage error (MAPE), secondly, by the frequency distribution of differences between estimated FW and fetal BW, and thirdly by comparing detection and false positive rates in screening for fetuses with a BW of 4,000, 4,300 and 4,500 g or more. Results: MPE ranged from –62.2 to 9.6% and was closest to 0 with the Hart formula. With 12 of 36 weight estimation formulae, MAPE was 10% or less, and was smallest with the Hart formulae (3.9%). The mean detection rate among all formulae for fetuses with a BW ≧4,000, ≧4,300 and ≧4,500 g was 29, 24 and 22%, respectively, and the false positive rate was 12% (for ≧4,300 g) and 7% (≧4,500 g). Discussion: Some formulae showed advantages as far as mean and absolute percentage errors were concerned, but none reached a detection rate and false positive rate for fetuses ≧4,500 g that could lead to clinical recommendation.

Intra- and interoperator reliability of manual and semi-automated measurement of fetal nuchal translucency by sonographers with different levels of experience

To compare the intra‐ and interoperator reliability of manual and semi‐automated nuchal translucency thickness (NT) measurement by sonographers with different levels of experience.

Idiopathic polyhydramnios and postnatal abnormalities.

Objective: To investigate the proportion and type of fetal anomalies that are associated with polyhydramnios and to examine whether in cases with idiopathic polyhydramnios during the course of pregnancy and fetal anomalies only diagnosed after birth, antenatal characteristics differ. Methods: This was a retrospective study involving all pregnancies with polyhydramnios defined by a deepest pool of amniotic fluid ≥8 cm and a detailed ultrasound examination, a 75 g glucose tolerance test and a TORCH serology. Results: Between 2004 and 2010, 272 pregnancies fulfilled the inclusion criteria. In 89 (32.7%) and 65 (23.9%) cases, there was a fetal anomaly or diabetes. In 118 (43.4%) pregnancies, polyhydramnios was classified as idiopathic. In 11 (9.3%) of the 118 fetuses, an anomaly was found after birth, mainly gastrointestinal atresia. In these cases, median deepest pool of amniotic fluid was 9.6 cm, and median estimated fetal weight was at the 69th centile, whereas in cases without anomalies diagnosed after birth, median deepest pool was 9.0 cm and median estimated fetal weight at the 90th centile (Mann-Whitney U test: deepest pool p = 0.116, and estimated fetal weight centile p = 0.377). There was also no difference in the maternal and gestational age distribution of these cases (Mann-Whitney U test: maternal age p = 0.293, and gestational age p = 0.499). Conclusion: In about 40% of pregnancies, polyhydramnios remains unexplained during the course of pregnancy. In 10% of these cases, an anomaly will only be found after birth. In this group, antenatal characteristics such as amniotic fluid volume, estimated fetal weight or gestational and maternal age at the time of diagnosis do not help to detect these anomalies before birth.

Granulocytic Myeloid-Derived Suppressor Cells Accumulate in Human Placenta and Polarize toward a Th2 Phenotype

Tolerance induction toward the semiallogeneic fetus is crucial to enable a successful pregnancy; its failure is associated with abortion or preterm delivery. Skewing T cell differentiation toward a Th2-dominated phenotype seems to be pivotal in maternal immune adaption, yet underlying mechanisms are incompletely understood. Myeloid-derived suppressor cells (MDSCs) are innate immune cells that mediate T cell suppression and are increased in cord blood of healthy newborns and in peripheral blood of pregnant women. In this study, we demonstrate that granulocytic MDSCs (GR-MDSCs) accumulate in human placenta of healthy pregnancies but are diminished in patients with spontaneous abortions. Placental GR-MDSCs effectively suppressed T cell responses by expression of arginase I and production of reactive oxygen species and were activated at the maternal–fetal interface through interaction with trophoblast cells. Furthermore, GR-MDSCs isolated from placenta polarized CD4+ T cells toward a Th2 cytokine response. These results highlight a potential role of GR-MDSCs in inducing and maintaining maternal–fetal tolerance and suggest them as a promising target for therapeutic manipulation of pregnancy complications.

First trimester ultrasound screening for Down syndrome based on maternal age, fetal nuchal translucency and different combinations of the additional markers nasal bone, tricuspid and ductus venosus flow

To examine the performance of screening for Down syndrome based on maternal age, fetal nuchal translucency (NT) and different combinations of the additional ultrasound parameters: nasal bone (NB), tricuspid flow (TF) and ductus venosus (DV).

Effect of Magnesium on Red Blood Cell Deformability in Pregnancy

Objective. Red blood cell (RBC) deformability is an important factor in determining movement of red blood cells through the microcirculation. In preeclampsia and some cases of intrauterine growth restriction (IUGR), RBC deformability and microcirculation are reduced. Magnesium is administered to reduce the risk of seizures. The aim of this study was first to detect the effect of intravenous magnesium application (2 g/h) on the deformability of RBCs in pregnancies with normal RBC deformability, receiving magnesium as tocolytic agent. The second aim was to examine the effect of calcium-antagonists (magnesium, nifedipin) on the deformability of RBC of preeclamptic patients in vitro. Methods. Part 1: magnesium (2 g/h), fenoterol (270 µg/h) + verapamil (0.2 mg/h) or placebo (NaCl 0.9%) was administered intravenously to pregnant women with premature contractions to test the tocolytic effect. RBC-deformability was measured by laser diffractoscopy in all three groups. Blood samples were taken before, after 1 h and after 24 h of administration. Magnesium-plasma-levels were measured. Part 2: Blood samples from patients with preeclampsia were incubated in vitro with magnesium (2 mmol), nifedipine (0.25 mg/ml), or placebo (NaCl 0.9%). RBC deformability was measured before and 15 min, 1h, 2h, 6h, and 10h after start of the incubation. Results. Part 1: The initial RBC-deformability was the same in all groups (E=0.232 ± 0.017 in NaCl, 0.232 ± 0.023 in fenoterol + verapamil, 0.232 ± 0.019 in magnesium). After 1 h of administration, RBC-deformability was significantly greater with magnesium (0.254 ± 0.020) and Fenoterol + Verapamil (0.238 ± 0.02) compared to placebo (0.231 ± 0.015). After 24 h the effect on RBC deformability in the fenoterol + verapamil-group was gone (0.234 ± 0.021 compared to 0.234 ± 0.016 in placebo), while in the IV-magnesium-group RBC-deformability remained increased (E=0.241 ± 0.019). Statistical analysis of the influence of magnesium-plasma-levels showed the maximum effect at concentrations of 1.95–2.15mmol/l. Part 2: RBC-deformability in preeclampsia was reduced as predicted by previous studies (0.120 + 0.0086 versus 0.232 in normal pregnancy). In vitro incubation with magnesium enhanced RBC-deformability in preeclampsia. Even after 15 min, a statistically significant effect was seen (0.127 ± 0.0091 versus 0.121 ± 0.0091 in placebo). Maximum effect was reached after 6 h of incubation (0.159 ± 0.0093 versus 0.133 ± 0.0091). Incubation with Nifedipine also enhanced RBC deformability [0.127 ± 0.0091 after 15 min, 0.149 ± 0.010 after 6 h (maximum effect)], but the effect was less pronounced than with magnesium. Conclusion. Intravenous magnesium therapy over a 24-hour period increases RBC-deformability even in pregnancies with normal RBC-deformability. In vitro measurements show an increase of RBC-deformability in preeclampsia in response to magnesium, which could offer additional therapeutic benefit for the treatment of reduced blood flow seen in most cases of preeclampsia.

Heart rate variability parameters and fetal movement complement fetal behavioral states detection via magnetography to monitor neurovegetative development

Fetal behavioral states are defined by fetal movement and heart rate variability (HRV). At 32 weeks of gestational age (GA) the distinction of four fetal behavioral states represented by combinations of quiet or active sleep or awakeness is possible. Prior to 32 weeks, only periods of fetal activity and quiesence can be distinguished. The increasing synchronization of fetal movement and HRV reflects the development of the autonomic nervous system (ANS) control. Fetal magnetocardiography (fMCG) detects fetal heart activity at high temporal resolution, enabling the calculation of HRV parameters. This study combined the criteria of fetal movement with the HRV analysis to complete the criteria for fetal state detection. HRV parameters were calculated including the standard deviation of the normal-to-normal R–R interval (SDNN), the mean square of successive differences of the R–R intervals (RMSSD, SDNN/RMSSD ratio, and permutation entropy (PE) to gain information about the developing influence of the ANS within each fetal state. In this study, 55 magnetocardiograms from healthy fetuses of 24–41 weeks’ GA were recorded for up to 45 min using a fetal biomagnetometer. Fetal states were classified based on HRV and movement detection. HRV parameters were calculated for each state. Before GA 32 weeks, 58.4% quiescence and 41.6% activity cycles were observed. Later, 24% quiet sleep state (1F), 65.4% active sleep state (2F), and 10.6% active awake state (4F) were observed. SDNN increased over gestation. Changes of HRV parameters between the fetal behavioral states, especially between 1F and 4F, were statistically significant. Increasing fetal activity was confirmed by a decrease in PE complexity measures. The fHRV parameters support the differentiation between states and indicate the development of autonomous nervous control of heart rate function.

Prenatal evaluation of the position of the fetal conus medullaris

To determine the position of the fetal conus medullaris during pregnancy in relation to the last vertebral body and to examine its use in detecting skin‐covered spinal dysraphism.

Prefrontal space ratio in second- and third-trimester screening for trisomy 21.

To evaluate the prefrontal space ratio (PFSR) in second‐ and third‐trimester euploid fetuses and fetuses with trisomy 21.

Fecal incontinence after obstetric anal sphincter injuries

To determine obstetric variables associated with the long‐term prevalence of flatal and/or fecal incontinence among women who sustained obstetric anal sphincter injuries (OASIS).