Fetal microchimerism: self and non-self, finally who are we?

For a long time, the conventional view was that the fetus and maternal vascular system are kept separate. In fact there is a two-way traffic of immune cells through the placenta and the transplacental passage of cells is in fact the norm. The fetal cells can persist in a wide range of woman's tissue following a pregnancy or an abortion and she becomes a chimera. Fetal cells have been found in the maternal circulation and they were shown to persist for almost three decades in humans, thus demonstrating long-term engraftment and survival capabilities. Microchimerism is a subject of much interest for a number of reasons. Studies of fetal microchimerism during pregnancy may offer explanations for complications of pregnancy, such as preeclampsia, as well as insights into the pathogenesis of autoimmune disease which usually ameliorates during pregnancy. The impact that the persistence of allogenic cells of fetal origin and the maternal immunological response to them has on the mother's health and whether it is detrimental or beneficial to the mother is still not clear. Although microchimerism has been implicated in some autoimmune diseases, fetal microchimerism is common in healthy individuals. On the beneficial side, it has been proposed that genetically disparate fetal microchimerism provides protection against some cancers, that fetal microchimerism can afford the mother new alleles of protection to some diseases she has not, that fetal microchimerism can enlarge the immunological repertoire of the mother improving her defense against aggressor. Fetal cells are often present at sites of maternal injury and may have an active role in the repair of maternal tissues.     

Fetal MRI: is it really helpful?

Objective: The aim of this study is to emphasize on the diagnostic effectiveness of fetal MRI that led to increased utilization in fetal medicine as well as its value in prognosis and decision making in the modern obstetric practice. Methods: One hundred five (n = 105) pregnant women were referred for a fetal MRI examination after a high detailed ultrasound examination revealed a fetal abnormality. Fetal MRI was performed using 1, 5 Tesla units, with T1, T2-weighted and diffusion-weighted images. The findings were analyzed in comparison to the previous ultrasound findings, according to the fetal organ affected and the value of the MRI for therapeutic decision making was addressed. A statistical analysis was performed. Results: The fetal MRI provides a more accurate diagnosis compared to ultrasound examination, and when the ultrasound detects fetal anomalies, the MRI can efficiently either confirm or reject the finding, proving its high value for prenatal diagnosis and perinatal and management. The sensitivity, specificity and positive predictive value of fetal MRI as a screening tool approaches 100%. Conclusions: Despite the fact that ultrasound is the method of choice for fetal screening, MRI can add up significantly to the diagnosis and management of congenital abnormalities and the indications for MRI continue to increase as new sequences and shorter acquisition times evolve.     

Fetal Doppler: how to keep it safe?

Ultrasound's record of safety seems to be perfect, with no undisputed reports of adverse effects in humans. However, all epidemiologic studies published so far are based on information obtained with pre-1992 machines, when allowed maximal in-situ intensity for fetal use was increased. Many fetuses are examined very early in pregnancy, a time of greater vulnerability. Doppler can generate much higher level of acoustic energy than B-mode. The thermal index and the mechanical index are indicators of the 2 main potential effects of ultrasound including Doppler. To keep the fetus safe, knowledge of these potential bioeffects is mandatory as is understanding of how instrument controls alter the output. The 2 most important rules are: keep thermal index below 1 and use the lowest possible output for the shortest possible time compatible with obtaining diagnostic information.     

Fetal heart rate monitoring: is it salvageable?

Fetal heart rate monitoring was introduced in the 1960s. After a number of randomized controlled trials in the mid 1980s, doubt arose regarding the efficacy of fetal heart rate monitoring in improving fetal outcome. The potential reasons why fetal heart rate monitoring has not been shown to be efficacious are (1) use of an outcome measure that is not related to variant fetal heart rate monitoring patterns, (2) lack of standardized interpretation of fetal heart rate patterns, (3) disagreement regarding algorithms for intervention of specific fetal heart rate patterns, and (4) the inability to demonstrate the reliability, validity, and ability of fetal heart rate monitoring to allow timely intervention. A recent National Institutes of Health committee proposed detailed, quantitative, standardized definitions of fetal heart rate patterns, which can serve as a basis for determining whether fetal heart rate monitoring is reliable and valid. In this article we examine reasons why fetal heart rate monitoring did not live up to its original expectations and why the randomized controlled trials did not demonstrate efficacy, and we make suggestions for determining whether electronic fetal heart rate monitoring should be abandoned.     

Fetal brain MRI in polyhydramnios: is it justified?

Abstract

Introduction: Despite meticulous investigation of polyhydramnios cases, in many of these cases, congenital anomalies are detected only after birth. The aim of our study was to explore the contribution of fetal brain MRI to the detection of CNS anomalies in cases of polyhydramnios.

Materials and methods: This was retrospective cohort study on fetuses referred for the investigation of polyhydramnios at a single tertiary center. All fetuses underwent a detailed sonographic anatomical scan and a fetal brain MRI. Isolated and nonisolated polyhydramnios were differentiated according to associated anomalies. MRI findings were compared between the groups.

Results: A total of 46 fetuses were included in the study. Brain anomalies were detected in ultrasound in 12 (26%) cases while MRI detected brain anomalies in 23 (50%) cases. MRI detected more anomalies in fetuses with nonisolated compared to isolated polyhydramnios (62.9% and 31.6%, respectively, p?=?.019).

Conclusions: Fetal brain MRI may contribute to the evaluation of fetuses with polyhydramnios. The clinical value and cost-effectiveness of MRI use in the routine work-up of polyhydramnios should be assessed in future studies.     

Fetal and neonatal cytopenias: what have we learned?

Rh disease has largely disappeared as a result of prophylaxis with anti-D. However, the cases that remain are more complicated with a combination of novel challenges with regard to in utero management with transfusion and its effects on the course of the neonate, both early and late. Thrombocytopenia in the neonate can be severe and recurrent if it is a result of alloimmunization. Newer techniques in the laboratory have improved the security of diagnosis. Antenatal management of affected fetuses with treatment administered to the mother is now well established although studies are ongoing. Neutropenia is a complication of pre-eclampsia; the mechanism is still not well understood.     

Endometrial ablation: where have we been? Where are we going?

Endometrial ablation (EA) is targeted destruction of the endothelial surface of the uterine cavity. The procedure was originally designed as a less invasive alternative to hysterectomy for the symptom of heavy menstrual bleeding unrelated to structural pathology of the uterus, that was not responsive to medical therapy. More recently it has become apparent that the procedure can be performed in the presence of submucous leiomyomas, providing they meet a number of size and location criteria. The first EA serie as published in Germany in the 1930s, but the procedure did not attract much attention until the latter part of the 20th century. Currently, EA can be performed under endoscopic direction with the neodymium:yttrium alumnum garnet laser, with a radiofrequency resectoscope, or with an expanding array of nonresectoscopic EA systems. It is apparent that most but not all of the complications associated with resectoscopic endometrial ablation are eliminated with nonresectoscopic endometrial ablation, but serious morbidity has been reported with all of the newer systems to date. Success and patient satisfaction seem to be enduring in the majority of well-selected patients treated in clinical trials, but repeat surgery, usually hysterectomy, is performed in 25% to 40% by 5 years after surgery. Increased efficiencies should be realized if the procedure could be moved to an office setting.     

Fetal cerebral ventriculomegaly: What do we tell the prospective parents?

Fetal cerebral ventriculomegaly is a relatively common finding, observed during approximately 1% of obstetric ultrasounds. In the second and third trimester, mild (≥10 mm) and severe ventriculomegaly (≥15 mm) are defined according to the measurement of distal lateral ventricles that is included in the routine sonographic examination of central nervous system. A detailed neurosonography and anatomy ultrasound should be performed to detect other associated anomalies in the central nervous system and in other systems, respectively. Fetal MRI might be useful when neurosonography is unavailable or suboptimal. The risk of chromosomal and non-chromosomal genetic disorders associated with ventriculomegaly is high, therefore invasive genetic testing, including microarray, is recommended. Screening for prenatal infections, in particular cytomegalovirus and toxoplasmosis, should also be carried out at diagnosis. The prognosis is determined by the severity of ventriculomegaly and/or by the presence of co-existing abnormalities. Fetal ventriculoamniotic shunting in progressive isolated severe ventriculomegaly is an experimental procedure. After delivery, ventricular-peritoneal shunting or ventriculostomy are the two available options to treat hydrocephalus in specific conditions with similar long-term outcomes. A multidisciplinary fetal neurology team, including perinatologists, geneticists, pediatric neurologists, neuroradiologists and neurosurgeons, can provide parents with the most thorough prenatal counseling. This review outlines the latest evidence on diagnosis and management of pregnancies complicated by fetal cerebral ventriculomegaly.