Pathogenic mitochondrial mt-tRNA(Ala) variants are uniquely associated with isolated myopathy

Pathogenic mitochondrial DNA (mtDNA) point mutations are associated with a wide range of clinical phenotypes, often involving multiple organ systems. We report two patients with isolated myopathy owing to novel mt-tRNA(Ala) variants. Muscle biopsy revealed extensive histopathological findings including cytochrome c oxidase (COX)-deficient fibres. Pyrosequencing confirmed mtDNA heteroplasmy for both mutations (m.5631G>A and m.5610G>A) whilst single-muscle fibre segregation studies (revealing statistically significant higher mutation loads in COX-deficient fibres than in COX-positive fibres), hierarchical mutation segregation within patient tissues and decreased steady-state mt-tRNA(Ala) levels all provide compelling evidence of pathogenicity. Interestingly, both patients showed very high-mutation levels in all tissues, inferring that the threshold for impairment of oxidative phosphorylation, as evidenced by COX deficiency, appears to be extremely high for these mt-tRNA(Ala) variants. Previously described mt-tRNA(Ala) mutations are also associated with a pure myopathic phenotype and demonstrate very high mtDNA heteroplasmy thresholds, inferring at least some genotype:phenotype correlation for mutations within this particular mt-tRNA gene.

Use of intrapartum ultrasound in the prediction of complicated operative forceps delivery of fetuses in non-occiput posterior position

OBJECTIVE

To evaluate the hypothesis that intrapartum ultrasound (ITU) measurements, including the angle of progression (AOP), progression distance (PD) and head direction (HD), can predict complicated forceps delivery in non-occiput posterior deliveries.

METHODS

In this prospective observational study, a single operator performed ITU on 30 patients with an indication for operative forceps delivery. Managing obstetricians were blinded to the results. ITU was performed just before blade application, between contractions and concurrently with contractions and active pushing. Forceps delivery was classified as complicated when one or more of the following situations occurred: three or more tractions; a subjective impression of a difficult or failed application; a third-degree or higher perineal tear; significant bleeding during the episiotomy repair; major tear; significant traumatic neonatal lesion.

RESULTS

Twenty-one forceps deliveries were classified as uncomplicated and nine were complicated. The strongest predictor of a complicated forceps delivery, calculated using the area under the receiver-operating characteristics curve (AUC), was the AOP between contractions (AOP1) (AUC = 98.9%). The best cut-off for predicting a difficult forceps delivery was an AOP1 of 138° (sensitivity = 85.7%, specificity = 100%). The best predictive model included both the AOP1 and the HD during a contraction with active pushing (HD2).

CONCLUSION

The sonographic parameters AOP and HD can be used to predict complicated operative forceps delivery in fetuses in non-occiput posterior position.

Three-dimensional ultrasound of massive macroglossia in a fetus with Beckwith-Wiedemann syndrome

We present the prenatal ultrasound findings of massive macroglossia in a fetus with prenatally diagnosed Beckwith-Wiedemann syndrome. Three-dimensional surface mode ultrasound was utilized for enhanced visualization of the macroglossia.

Vasa praevia: risk-adapted modification of the conventional management--a retrospective study

PURPOSE

Undiagnosed vasa praevia carries an imminent risk of fetal death and increases with IVF. When diagnosed, the question arises as to whether the conventional prenatal management of routine steroid administration for fetal lung maturation and elective caesarean section in week 35 is generally justified in face of the risks involved. We present a retrospective study of a risk-adapted modification of the conventional management of vasa praevia.

MATERIAL AND METHODS

We analysed 11 years of records involving 18 cases of antenatally diagnosed vasa praevia at our perinatal centre. Each case was managed by a risk-adapted modification of the conventional treatment where both, the steroid administration and the timing of delivery, were dependent on the patient history and clinical signs for preterm birth.

RESULTS

There were no lethal fetal, neonatal, or maternal complications. The earliest caesarean section took place at 34 weeks 1 day, the latest at 37 weeks 1 day, and in more than half of the cases at ≥ 36 weeks.

CONCLUSION

Steroid application is generally recommended for pregnancies before 34 weeks carrying a risk for preterm birth. Thus, retrospectively, none of our cases required steroid administration. This supports our protocol of not obligatorily administering steroids. Delaying the caesarean section up to two weeks beyond the conventionally recommended date of 35 weeks in 78% of our cases resulted in no complications. This justifies the suitability of determining the timing of delivery based on our individual patient assessment. In conclusion, the following recommendations for a risk-adapted management of vasa praevia can be made: 1. weekly evaluation of risk factors for preterm delivery; 2. steroid administration only at risk for preterm birth; 3. admission to hospital with full obstetric and neonatal care facilities between 32 and 34 weeks; 4. elective caesarean section between 35 and 37 weeks, risk-adapted.

Genetic low nephron number hypertension is associated with altered expression of osteopontin and CD44 during nephrogenesis

AIMS

The study set out to investigate whether the osteopontin (OPN)-CD44-integrin-receptor-system is differently regulated during nephrogenesis in inborn nephron deficit, a major determinant of human primary hypertension and cardiovascular disease in adult life.

METHODS

We compared a genetic rat model with an inherited nephron deficit, the Munich-Wistar-Froemter rat (MWF), to normotensive Wistar rats during nephrogenesis at day 19 of fetal development (E19) and at postpartal day 7 (D7).

RESULTS

Renal OPN mRNA (-75%, P<0.05) and protein expression (-38%, P<0.05) were strongly decreased at E19 in MWF compared to Wistar. Renal mRNA-expression of CD44 was increased at E19 in MWF (+271%, P<0.05). At D7, renal OPN protein expression was increased (+115%, P<0.05) and renal mRNA-expression of CD44 remained elevated compared to Wistar control (+127%, P<0.05).

CONCLUSIONS

Altered fetal expression of the OPN-CD44-integrin-receptor-system in the MWF model points to a possible role in low nephron number hypertension and cardiovascular disease.

Value of Doppler sonography near term: can umbilical and uterine artery indices in low-risk pregnancies predict perinatal outcome?

AIM

The goal of this study was to evaluate the umbilical and uterine Doppler velocimetry waveforms for predicting the perinatal outcome of low-risk pregnancies at term.

METHODS

We prospectively recruited 514 women with low risk pregnancies and performed umbilical and uterine artery Doppler assessments between 37 and 41 weeks of gestation. Ultrasound measurements (completed in 365 patients) were correlated with the perinatal outcome.

RESULTS

The velocimetry waveforms of the umbilical artery were significantly associated with birthweight, placental weight, and postpartal umbilical artery pH. Low pH, placental weight, and birthweight were correlated with increasing pulsatility index (PI) and resistance index (RI). An umbilical artery PI > 1.2 and a uterine artery RI > 0.5 were associated with statistically higher rates of infants that were small for gestational age (SGA). Also, high cesarean delivery rates were correlated with an umbilical artery PI > 1.2.

CONCLUSIONS

In our low-risk pregnancies population, the elevated umbilical artery indices at term appeared to be associated with the higher rates of infants that were SGA and cesarean deliveries. The Doppler waveforms at term had low prognostic value for predicting neonatal acidosis or decreased Apgar scores.

Proteomic analysis of midtrimester amniotic fluid to identify novel biomarkers for preterm delivery

OBJECTIVE

The aim of this study was to identify possible biomarkers for preterm delivery by analyzing midtrimester amniotic fluid.

METHODS

Thirty-two amniotic fluid samples were studied; 16 patients had a spontaneous preterm delivery and 16 patients delivered at term. The proteomic technique consisted of surface-enhanced laser desorption ionization time-of-flight (SELDI-TOF) using different types of solid chromatographic chips (Q10, CM10 and IMAC30).

RESULTS

Mass spectrometry tracings were obtained from the amniotic fluids of both patients who delivered preterm and patients who delivered at term. Seven potential markers were identified to be differentially expressed in patients who delivered preterm.

CONCLUSIONS

Proteomic analysis of amniotic fluid obtained in the midtrimester reveals the presence of a set of proteins in patients at risk for preterm delivery.

Human birth observed in real-time open magnetic resonance imaging

OBJECTIVE

Knowledge about the mechanism of labor is based on assumptions and radiographic studies performed decades ago. The goal of this study was to describe the relationship between the fetus and the pelvis as the fetus travels through the birth canal, using an open magnetic resonance imaging (MRI) scanner.

STUDY DESIGN

The design of the study used a real-time MRI series during delivery of the fetal head.

RESULTS

Delivery occurred by progressive head extension. However, extension was a very late movement that was observed when the occiput was in close contact with the inferior margin of the symphysis pubis, occurring simultaneously with gliding downward of the fetal head.

CONCLUSION

This observational study shows, for the first time, that birth can be analyzed with real-time MRI. MRI technology allows assessment of maternal and fetal anatomy during labor and delivery.

Magnetic resonance imaging of the active second stage of labour: proof of principle

OBJECTIVE

To prove that magnetic resonance imaging of foetal anatomy during the active second stage of vaginal delivery is feasible.

MATERIALS AND METHODS

Initially, five pregnant volunteers around the 30th week of gestation were examined in an open MRI. Based on the findings, one vaginal delivery was acquired under real-time imaging. To monitor the birth status during image acquisition, an MR-compatible wireless cardiotocography (CTG) system was built. Single-shot sequence parameters were optimised to compensate motion artefacts during labour.

RESULTS

Safety requirements to monitor the birth process under real-time MR imaging were met. High-resolution MR images were acquired immediately before and after delivery. In one patient, TSE single-shot cinematic sequences of the active second stage of labour were obtained. All sequences were adapted to tolerate movement of the mother and infant, as well as residual noise from the CTG. Furthermore, the MR imaging during labour showed only minor image artefacts.

CONCLUSION

CTG-monitored acquisition of MRI series during the active second stage of delivery is feasible. Image quality should allow various further studies to improve models for birth simulation as well as potential investigation of obstructed labour and obstetric complications.

Angle of progression measurements of fetal head at term: a systematic comparison between open magnetic resonance imaging and transperineal ultrasound

OBJECTIVE

During labor, transperineal sonography is increasingly used to evaluate fetal head descent. The aim of this study was to compare the angle of progression assessed by open magnetic resonance imaging (MRI) vs transperineal ultrasound.

STUDY DESIGN

A total of 31 pregnant women at term (>37 weeks), who were not in labor, underwent MRI in an open 1.0-T system. A midsagittal plane of the maternal pelvis was stored. Immediately after, without changing the supine position, a transperineal ultrasound was performed. The angle of progression was measured offline by transperineal ultrasound and MRI.

RESULTS

The angles of progression measured by transperineal ultrasound (mean, 79.05 degrees; SD 11.44) and MRI (mean, 80.48 degrees; SD 11.06) correlated significantly (P < .001). The intraclass correlation coefficient between the 2 methods was 0.89 (95% confidence interval, 0.78-0.94).

CONCLUSION

The angle of progression measurements obtained by transperineal ultrasound and open MRI showed very good agreement.