The Psychological Impact of the COVID-19 Outbreak on Pregnancy and Mother-infant Prenatal Bonding.

This study aimed to assess the impact of the COVID-19 stress and anxiety on prenatal attachment during the second trimester of gestation. Pregnancy is an important stage for mothers-to-be in creating representations of themselves as a "mother", with the developing attachment relationship to the unborn child considered as a milestone in the future parent's developmental trajectory. The outbreak of the COVID-19 pandemic and the national health measures installed can hence have consequences on these representations and on prenatal attachment. Our sample consisted of 95 mothers that were recruited from a prenatal ultrasound screening center. Results suggested that the COVID-19 pandemic significantly affected prenatal attachment (PAI) with significant correlations between PAI total score and age, anxiety (DASS) and stress (IES-R). When entered in one model looking for predictors of PAI total score, age and COVID-19 stress were the only variables found to significantly predict prenatal attachment. We argue for a cultural component in explaining these results, hypothesizing that stress could trigger defensive strategies, leading to more investment in the attachment relationship, potentially playing the role of a protective factor.

Biplane mode for more precise intrauterine procedures.

The evolution of ultrasound and the introduction of 3- and 4-dimensional ultrasound techniques led to a shift in the perception and usage of ultrasound in fetal medicine. The biplane mode might help in multiple fetal procedures, including but not limited to basic intrauterine thoracocentesis, thoracoamniotic shunting, amnioreduction, amnioinfusion, cordocentesis, intraumbilical infusion, and umbilical cord coagulation, with a possible reduction in the complication rate. Despite its theoretical usefulness, more studies are required to assess the clinical importance of this technique.

Letter to the Editor in response to 'Parental attachment and depressive symptoms in pregnancies complicated by twin-twin transfusion syndrome: a cohort study'.

Twin-twin transfusion syndrome is a highly morbid condition that can affect parental attachment and depression risk. Studies addressing this rare condition are hard to conduct and thus lacking in the literature. In this letter to the editor, we acknowledge the article of Mackie et al. entitled "Parental attachment and depressive symptoms in pregnancies complicated by twin-twin transfusion syndrome: a cohort study" to be of high importance and impact, but would like to discuss the extent of its conclusions, and push towards bigger studies in this field.

Announcing fetal pathology: Challenges encountered by physicians and potential role of simulation in training for breaking bad news.

BACKGROUND: Informing couples about the diagnosis of severe fetal pathologies is part of the daily routine in fetal medicine. This situation is usually complex and can put untrained professionals in an uncomfortable position. The aim of this study was to assess the perception of health care professionals when faced with the need to announce a fetal pathology in order to target their training gaps in this domain. MATERIALS AND METHODS: A questionnaire was created and disseminated on a national level among physicians practicing or collaborating with the multidisciplinary centers of prenatal diagnosis in France. The questionnaire focused on the difficulties encountered by practitioners when announcing fetal pathologies, and their potential interest in simulation sessions regarding the delivery of bad news. RESULTS: 193 participants filled the questionnaire. 65 % report not receiving any theoretical courses in this field during their initial training, 49 % admit feeling uncomfortable when a fetal anomaly needs to be announced, 79.5 % think that role-play could help them, 87.5 % believe that training sessions in communication skills would help improve their methods and 73.1 % support teaching the delivery of bad news by simulation sessions. CONCLUSION: This survey illustrates the significance of announcing a fetal pathology for fetal medicine professionals. Many of them report not being properly trained to cope with this situation and would like to improve with a more practical way of teaching. Simulation would be the ideal educational tool to meet this demand.

Obstetric Ultrasound Screening in a Rural Area of Lebanon One Small Step With a Promising Major Impact.

OBJECTIVES: Our aim was to evaluate the conditions and to weigh the potential impact of an obstetrical ultrasound screening intervention on pregnant patients in an underserved area of Lebanon with the presence of refugees. METHODS: We performed a cross-sectional study in a rural region in North Lebanon. Monthly second-trimester obstetrical ultrasound scans were offered to patients. A thorough analysis of the population's characteristics was done, the anomalies discovered were documented and follow up recommendations were offered. RESULTS: 268 screening ultrasounds were performed over a one-year period. The patients' mean age was 27.5 ± 8.5 years with a 35% consanguinity rate. A positive personal history of abnormalities was recognized in 34% of cases, and a positive family history in 21% of them. The average gestational age was of 23.3 ± 1.4 weeks of gestation. We found a rate of 8.6% inaccurate dating, 20% growth abnormalities, and 12% morphological abnormalities requiring follow-up. These latter included defects affecting multiple organ systems among which renal, neurological, and cardiac structures were the most frequently affected (2.5%, 2%, and 1.6% respectively). Overall, 35.8% of the screened cases required a follow-up for 1 or more abnormal findings. CONCLUSIONS: The findings confirmed the necessity to introduce a prenatal ultrasound screening program in rural areas of Lebanon where refugees are settled. The lack of adequate ultrasound screening in these regions presents major threats that can hinder any pregnancy. Our simple intervention tackles the burden of diagnosis of these risks in up to 35.8% of pregnancies and thus can help improve outcomes.

Management of monochorionic twins discordant for structural fetal anomalies.

OBJECTIVE: To review the perinatal management and outcomes of monochorionic twin pregnancies (MC) discordant for congenital anomalies (DCA). METHODS: Retrospective, study of all MC DCA cases referred to our tertiary referral center from 1997 to 2018. We excluded cases complicated with twin-to-twin transfusion syndrome, twin anemia-polycythemia sequence, twin reversed arterial perfusion sequence or selective intra-uterine growth restriction. Patients were counseled about the possibility of expectant (EM) or interventional management (selective feticide [SF] or termination of the entire pregnancy [TOP]). RESULTS: One hundred eight of 4157 (2.6%) MC pregnancies were discordant for anomaly. Fifty two of 108 n(48.1%) underwent SF at a mean gestational age of 31.4 ± 5.9 weeks while 52/108(48.1%) opted for EM. Livebirth rate of the healthy co-twin was similar between the two groups (SF: 88.5% vs EM: 82.7%, P = .87). In the SF group, six healthy co-twins (6/52, 11.5%) died 5.3 ± 3.1 days after SF of the abnormal co-twin. In the EM group, in-utero demise of the abnormal twin occurred in 9 of 52 (17.3%) of the cases and was followed by the spontaneous demise of the healthy co-twin in 4 of 9 (44.4%) of these cases. CONCLUSION: Selective feticide does not seem to significantly alter survival of the healthy co-twin compared to EM.

Quantitating skill acquisition with optical ultrasound simulation.

OBJECTIVE: To investigate and compare the effect of simulator training on quantitative scores for ultrasound-related skills for trainees with novice level ultrasound experience and expert ultrasound operators. METHODS: Three novice (comprising of 11, 32, 23 participants) and one expert (10 participants) subgroups undertook an ultrasound simulation training session. Pre- and post-training test scores were collected for each subgroup. Outcome measures were as follows: mean accuracy score for obtaining the correct anatomical plane, percentage of correctly acquired target planes, mean number of movements, time to achieve image, distance travelled by probe and accumulated angling of the probe. RESULTS: The novices showed improvement in image acquisition after completion of the simulation training session with an improvement in the rate of correctly acquired target planes from 28-57% to 39-83%. This was not replicated in the experts. The novice's individual ratios based on pre- vs. post-training metrics improved between 1.7- and 4.3-fold for number of movements, 1.9- and 6.7-fold for distance, 2.0- and 5.2-fold for time taken and 1.8- and 7.3-fold for accumulated angling. Among the experts, there was no relationship between pre-training simulator metrics and years of ultrasound experience. CONCLUSIONS: The individual simulation metrics suggest the sessions were delivered at an appropriate level for basic training as novice trainees were able to show demonstrable improvements in both efficiency and accuracy on the simulator. Experts did not improve after the simulation modules, and the novice scores post-training were similar to those of experts, suggesting the exercises were valid in testing ultrasound skills at novice but not expert level.

The use of fetal MRI for renal and urogenital tract anomalies.

Fetal anomalies are detected in approximately 2% of all fetuses and, among these, genitourinary tract abnormalities account for 30% to 50% of all structural anomalies present at birth. Although ultrasound remains the first line diagnostic modality, fetal MRI provides important additional structural and functional information, especially with the development of faster sequences and the use of functional sequences. The added value of MRI-based imaging is three-fold: (a) improvement of diagnostic accuracy by adequate morphological examination, (b) detection of additional anomalies, and (c) in addition, MRI has the potential to provide information regarding renal function. In this review, we describe the role of fetal MRI in the anatomical evaluation of renal and urogenital tract anomalies, and we also touch upon the contribution of functional MRI to the diagnostic workup of these conditions.

Non-invasive assessment of placental perfusion in vivo using arterial spin labeling (ASL) MRI: A preclinical study in rats.

INTRODUCTION: Non-invasive assessment of placental perfusion is of great interest to characterize placental function in clinical practice. This article proposes a strictly non-invasive MRI technique using ASL to quantify placental blood flow in vivo. The aim of this study was to develop a fMRI tool to quantify placental blood flow (PBF) in rat, by using arterial spin labeling (ASL) MRI at 4.7 T. MATERIALS AND METHODS: MRI was performed with a dedicated magnet for small animals, in pregnant rats on day 20 of the 22-day gestation period. A Look-Locker flow-sensitive alternating inversion recovery gradient echo sequence was developed as ASL technique (TE: 1.55 ms; TR: 3.5 ms, TI: 56 ms, deltaTI: 56 ms, FA: 20°, Matrix: 128 × 128, 8 segments, 4 Nex). Labeling was performed with global and slice-selective inversions, and T1 map was obtained for each mode of inversion. PBF was then derived from a compartmental model of the variation of T1 between global and slice-selective inversions. RESULTS: The full protocol was completed and ASL image post-processing was successful in 18 rats. Forty-seven placentas were analyzed, with a mean PBF of 147 ±â€¯70 ml/min/100 g of placenta, consistent with published values of placental perfusion using invasive techniques. CONCLUSION: ASL MRI is feasible for the quantification of PBF in rats at 4.7 T. This technique, which requires no administration of contrast media, could have implications for non-invasive longitudinal and in vivo animal studies and may be useful for the management of human pregnancies.

Fetoscopic Release of Amniotic Bands Causing Limb Constriction: Case Series and Review of the Literature.

The aim of this study was to review the perioperative complication rates and neonatal outcomes after fetoscopic release of amniotic bands that caused bilateral limb constrictions. We present 5 cases of limb constriction by amniotic bands occurring spontaneously or following fetoscopic surgery and also include a review of 21 previously published cases. The cases were analyzed for indication, surgical technique, and postoperative follow-up. In our population and the literature, the majority of the children acquired a functional limb (75%), with few perioperative complications (15%). Fetal morbidity was mainly linked to the consequences of preterm premature rupture of the membranes (38.4%) and preterm birth (34.7 GW). The mortality rate was low (7.7%). This review only describes amniotic bands causing limb constriction, and illustrates that fetoscopic surgery for their release is technically feasible with an acceptable perioperative complication rate. However, the 75% success rate is very likely to be an overestimation of the true success rate. In view of these observations we cannot recommend treatment for cases where the fetus has been extensively affected by the bands. We believe, however, that we could consider this technique for a fraction of amniotic band syndrome cases isolated to the limb constrictions. This kind of surgery should be proposed as a potential treatment for amniotic band syndrome.

Assessment of human placental perfusion by intravoxel incoherent motion MR imaging.

PURPOSE: To provide functional information on the human placenta, including perfusion, and diffusion, with no contrast agent injection, and to study correlations between intravoxel incoherent motion (IVIM) placental parameters and fetal growth. MATERIALS AND METHODS: MRI was performed in women undergoing legal termination of pregnancy at 17-34 weeks, including a 4-b-value and 11-b-value DW sequences. The apparent diffusion coefficient (ADC), the restricted diffusion coefficient (D), the pseudoperfusion coefficient (D*), and the perfusion fraction (f) were calculated. Their relationships with gestational age, Z-scores for fetal and placental weight were evaluated by means of regression analysis. Logistic regression analysis was used to assess the ability of IVIM parameters to predict/detect intrauterine growth retardation (SGA). RESULTS: Fifty-five pregnant women, including nine cases of SGA (16%), were included in the study. The ADC (n = 55) showed a quadratic correlation with gestational age (p < .001) and a linear correlation with the fetal weight Z-score (p = .02). Mean ADC values were significantly different between normally growing and SGA fetuses (2.37 ± 0.25 versus 2.29 ± 0.33 10-3.mm2.s-1, p=.048). The perfusion fraction f (n = 23) showed a quadratic correlation with gestational age (p = .017) and a linear correlation with the fetal weight Z - score (p = .008). Mean f values differed significantly between normally growing and SGA fetuses (42.55 ± 9.30% versus 27.94 ± 8.76%, p = .002). The receiver operating characteristics (ROC) curve for f to predict SGA was produced (area under the ROC curve = 0.9). CONCLUSIONS: The observed association between f and fetal weight suggests that fMRI could be suitable for studying placental insufficiency and for identifying risk of SGA.

Prenatal incision of ureterocele causing bladder outlet obstruction: a multicenter case series.

We reviewed data from a cohort of fetuses with ureterocele diagnosed and operated prenatally in four fetal therapy centers. Inclusion criteria were (1) ureterocele confirmed on detailed fetal ultrasound examination, (2) absence of additional fetal malformations, and (3) fetal intervention to decompress the ureterocele with local institutional review boards' approval. Data on sonographic follow-up, obstetrical, neonatal outcome, and postnatal evaluation were collected. Ten cases of prenatally treated ureterocele are described. Six cases benefited from a fetoscopy for laser incision and decompression, two cases had an ultrasound guided puncture before resorting to a fetoscopy with laser incision, one case had a balloon catheterization under ultrasound guidance, and one case had an ultrasound-guided opening of the ureterocele with a laser fiber passed through a 20-gauge needle. Mean gestational age at diagnosis was 21.6 GW. Two cases underwent termination of pregnancy. The remaining eight cases recovered normal amniotic fluid volume and delivered a liveborn child at a mean gestational age of 38.6 GW with normal creatinine levels during the first week of life. Prenatal incision provided complete treatment of severely obstructive ureteroceles in 80% of the cases and allowed improvement of urinary electrolytes, renal size and echogenicity, bladder filling in all survivors, and recollection of normal amniotic fluid volume, in case of oligoanhydramnios. © 2017 John Wiley & Sons, Ltd.

Hyperechogenic kidneys and polyhydramnios associated with HNF1B gene mutation.

BACKGROUND: HNF1B mutation is the leading cause of isolated hyperechogenic fetal kidneys with normal or moderately large size. Although most cases have normal amniotic fluid volume, some cases present with early oligohydramnios and renal failure associated with high perinatal mortality. CASE DIAGNOSIS/TREATMENT: Here we report on seven fetuses from six unrelated families, carrying an HNF1B mutation, and presenting with polyhydramnios during the second or third trimester of pregnancy. Polyhydramnios was transitory in two cases. None of the mothers was presenting gestational diabetes. Bilateral hyperechogenic kidneys with size between -2.5 and +2 SD was the most common renal phenotype at prenatal US. Two patients were born prematurely at 28 and 32 weeks of gestation, respectively. Both presented high urine output the first days of life with urinary salt and potassium loss requiring hydro-electrolytic compensation. All mutations were large deletions removing the whole HNF1B gene. CONCLUSIONS: In the absence of maternal diabetes, HNF1B mutation can be associated with polyhydramnios, probably due to fetal polyuria. Thus, HNF1B mutation represents a differential diagnosis of polyhydramnios associated with hyperechogenic (and sometimes enlarged) kidneys.

Impact of Monochorionicity and Twin to Twin Transfusion Syndrome on Prenatal Attachment, Post Traumatic Stress Disorder, Anxiety and Depressive Symptoms.

Monochronioric (MC) twin pregnancies are considered as high-risk pregnancies with potential complications requiring in-utero interventions. We aimed to assess prenatal attachment, anxiety, post-traumatic stress disorder (PTSD) and depressive symptoms in MC pregnancies complicated with Twin-To-Twin-transfusion syndrome (TTTS) in comparison to uncomplicated monochorionic (UMC) and dichorionic pregnancies (DC). Auto-questionnaires were filled out at diagnosis of TTTS and at successive milestones. Prenatal attachment, PTSD, anxiety and perinatal depression were evaluated respectively by the Prenatal Attachment Inventory (PAI) completed for each twin, the Post-traumatic Checklist Scale (PCLS), the State-Trait Anxiety Inventory (STAI) and the Edinburgh Perinatal Depression Scale (EPDS). There was no significant difference in the PAI scores between the two twins. In the DC and UMC groups, PAI scores increased throughout pregnancy, whilst it didn't for TTTS group. TTTS and DC had a similar prenatal attachment while MC mothers expressed a significantly higher attachment to their fetuses and expressed it earlier. At the announcement of TTTS, 72% of the patients present a score over the threshold at the EPDS Scale, with a higher score for TTTS than for DC (p = 0.005), and UMC (p = 0.007) at the same GA. 30% of mothers in TTTS group have PTSD during pregnancy. 50% of TTTS- patients present an anxiety score over the threshold (STAI-Scale), with a score significantly higher in TTTS than in UMC (p<0.001) or DC (p<0.001). The proportion of subject with a STAI-State over the threshold is also significantly higher in TTTS than in DC at 20 GW (p = 0.01) and at 26 GW (p<0.05). The STAI-state scores in UMC and DC increase progressively during pregnancy while they decrease significantly in TTTS. TTTS announcement constitutes a traumatic event during a pregnancy with an important risk of PTSD, high level of anxiety and an alteration of the prenatal attachment. These results should guide the psychological support provided to these patients.

Evaluation of trainees' ability to perform obstetrical ultrasound using simulation: challenges and opportunities.

BACKGROUND: Evaluation of trainee's ability in obstetrical ultrasound is a time-consuming process, which requires involving patients as volunteers. With the use of obstetrical ultrasound simulators, virtual reality could help in assessing competency and evaluating trainees in this field. OBJECTIVE: The objective of the study was to test the validity of an obstetrical ultrasound simulator as a tool for evaluating trainees following structured training by comparing scores obtained on obstetrical ultrasound simulator with those obtained on volunteers and by assessing correlations between scores of images and of dexterity given by 2 blinded examiners. STUDY DESIGN: Trainees, taking the 2013 French national examination for the practice of obstetrical ultrasound were asked to obtain standardized ultrasound planes both on volunteer pregnant women and on an obstetrical ultrasound simulator. These planes included measurements of biparietal diameter, abdominal circumference, and femur length as well as reference planes for cardiac 4-chamber and outflow tracts, kidneys, stomach/diaphragm, spine, and face. Images were stored and evaluated subsequently by 2 national examiners who scored each picture according to previously established quality criteria. Dexterity was also evaluated and subjectively scored between 0 and 10. The Raghunathan's modification of Pearson, Filon's z, Spearman's rank correlation, and analysis of variance tests were used to assess correlations between the scores by the 2 examiners and scores of dexterity and also to compare the final scores between the 2 different methods. RESULTS: We evaluated 29 trainees. The mean dexterity scores in simulation (6.5 ± 2.0) and real examination (5.9 ± 2.3) were comparable (P = .31). Scores with an obstetrical ultrasound simulator were significantly higher than those obtained on volunteers (P = .027). Nevertheless, there was a good correlation between the scores of the 2 examiners judging on simulation (R = 0.888) and on volunteers (R = 0.873) (P = .81). CONCLUSION: An obstetrical ultrasound simulator is as good a method as volunteer-based examination for evaluating practical skills in trainees following structured training in obstetrical ultrasound. The threshold for success/failure should, however, be adapted as candidates obtain higher scores on the simulator. Advantages of the obstetrical ultrasound simulator include the absence of location and time constraints without the need to involve volunteers or to interfere with the running of ultrasound clinics. However, an obstetrical ultrasound simulator still lacks the ability to evaluate the trainees' ability to interact with patients.

Functional imaging of the human placenta with magnetic resonance.

Abnormal placentation is responsible for most failures in pregnancy; however, an understanding of placental functions remains largely concealed from noninvasive, in vivo investigations. Magnetic resonance imaging (MRI) is safe in pregnancy for magnetic fields of up to 3 Tesla and is being used increasingly to improve the accuracy of prenatal imaging. Functional MRI (fMRI) of the placenta has not yet been validated in a clinical setting, and most data are derived from animal studies. FMRI could be used to further explore placental functions that are related to vascularization, oxygenation, and metabolism in human pregnancies by the use of various enhancement processes. Dynamic contrast-enhanced MRI is best able to quantify placental perfusion, permeability, and blood volume fractions. However, the transplacental passage of Gadolinium-based contrast agents represents a significant safety concern for this procedure in humans. There are alternative contrast agents that may be safer in pregnancy or that do not cross the placenta. Arterial spin labeling MRI relies on magnetically labeled water to quantify the blood flows within the placenta. A disadvantage of this technique is a poorer signal-to-noise ratio. Based on arterial spin labeling, placental perfusion in normal pregnancy is 176 ± 91 mL × min(-1) × 100 g(-1) and decreases in cases with intrauterine growth restriction. Blood oxygen level-dependent and oxygen-enhanced MRIs do not assess perfusion but measure the response of the placenta to changes in oxygen levels with the use of hemoglobin as an endogenous contrast agent. Diffusion-weighted imaging and intravoxel incoherent motion MRI do not require exogenous contrast agents, instead they use the movement of water molecules within tissues. The apparent diffusion coefficient and perfusion fraction are significantly lower in placentas of growth-restricted fetuses when compared with normal pregnancies. Magnetic resonance spectroscopy has the ability to extract information regarding metabolites from the placenta noninvasively and in vivo. There are marked differences in all 3 metabolites N-acetyl aspartate/choline levels, inositol/choline ratio between small, and adequately grown fetuses. Current research is focused on the ability of each fMRI technique to make a timely diagnosis of abnormal placentation that would allow for appropriate planning of follow-up examinations and optimal scheduling of delivery. These research programs will benefit from the use of well-defined sequences, standardized imaging protocols, and robust computational methods.

Randomized Clinical Trial of Virtual Reality Simulation Training for Transvaginal Gynecologic Ultrasound Skills.

OBJECTIVES: To compare the impact of virtual reality simulation training and theoretical teaching on the ability of inexperienced trainees to produce adequate virtual transvaginal ultrasound images. METHODS: We conducted a randomized controlled trial with parallel groups. Participants included inexperienced residents starting a training program in Paris. The intervention consisted of 40 minutes of virtual reality simulation training using a haptic transvaginal simulator versus 40 minutes of conventional teaching including a conference with slides and videos and answers to the students' questions. The outcome was a 19-point image quality score calculated from a set of 4 images (sagittal and coronal views of the uterus and left and right ovaries) produced by trainees immediately after the intervention, using the same simulator on which a new virtual patient had been uploaded. Experts assessed the outcome on stored images, presented in a random order, 2 months after the trial was completed. They were blinded to group assignment. The hypothesis was an improved outcome in the intervention group. Randomization was 1 to 1. RESULTS: The mean score was significantly greater in the simulation group (n = 16; mean score, 12; SEM, 0.8) than the control group (n = 18; mean score, 9; SEM, 1.0; P= .0302). CONCLUSIONS: The quality of virtual vaginal images produced by inexperienced trainees was greater immediately after a single virtual reality simulation training session than after a single theoretical teaching session.

Formative assessment based on an audit and feedback improves nuchal translucency ultrasound image quality.

OBJECTIVES: The purpose of this work was to study the impact of an audit and feedback on the quality of routine first-trimester nuchal transparency ultrasound images. METHODS: Eighty-eight sonographers were each sent 2 different series of 30 consecutive nuchal translucency images at a mean interval of 3 months to a dedicated, protected server for remote double-blind independent analysis based on the new Collège Français d'Echographie Foetale/Centre National de la Recherche Scientifique image-scoring method (https://www.cfef.org/evaluation/ISMCFEFCNRS.pdf). The sonographers were classified as low (score below the median) or high (score above the median) scorers for each series. Before their second evaluation, 73 of the 88 sonographers received a feedback report on their first series of images, whereas the other 15 participants received no feedback. The baseline characteristics of the participants who did and did not receive feedback were comparable. RESULTS: Participants who received feedback increased their average score significantly, from a mean ± SD of 11.1 ± 1.3 to 13.4 ± 1.4 among low scorers (P < .00001) and from 15.1 ± 1.2 to 16.0 ± 1.4 among high scorers (P < .001), whereas no significant change was seen among participants who received no feedback (low scorers, 10.9 ± 1.5 to 12.1 ± 2.0; P = .11; high scorers, 14.7 ± 1.3 to 14.6 ± 1.3; P = .99). The proportion of satisfactory images increased by 48% among low scorers who received feedback. CONCLUSIONS: Formative assessment based on a moderately intensive audit and feedback is feasible and effective for improving the quality of routine first-trimester nuchal transparency ultrasound images.

Fetoplacental oxygenation in an intrauterine growth restriction rat model by using blood oxygen level-dependent MR imaging at 4.7 T.

PURPOSE: To investigate blood oxygen level-dependent (BOLD) magnetic resonance (MR) imaging in an intrauterine growth restriction (IUGR) rat model as a noninvasive in vivo tool to evaluate the response of the fetoplacental units (FPUs) to oxygenation MATERIALS AND METHODS: All procedures were approved by the animal care committee. The study was performed between February and July 2010. The IUGR model based on the ligation of the left uterine vascular pedicle at embryonic day 17 of gestation was validated by weighing placentas and fetuses after MR imaging. FPUs in the left and right uterine horns were IUGR cases and controls, respectively. A small-animal 4.7-T MR imager was used. Multiple gradient-echo sequence (repetition time msec/echo time msec, 800/1.8-49.8) was performed at embryonic day 19. T2* relaxation time was measured before and after maternal hyperoxygenation for live FPUs in placenta, fetal liver, and brain. The effect of hyperoxygenation on BOLD MR imaging was analyzed with change in T2* between hyperoxygenation and ambient air. After dissection, live fetuses from both horns were identified and weighed. Changes in T2* were compared based on Student t tests. A mixed model was used to compare BOLD effect among horns and organs. RESULTS: Sixteen rats were studied. There was a significant fetal weight decrease in the IUGR FPUs (-21.9%; P < .001). Change in T2* differed significantly between IUGR cases and controls for placenta (5.25 msec vs 11.25 msec; P < .001) and fetal brain (3.7 msec vs 7.17 msec; P = .02), whereas there was no significant difference in the fetal liver (2.72 msec vs 3.18 msec; P = .47). CONCLUSION: BOLD MR imaging at 4.7 T can be used to evaluate the response to oxygenation in normal and IUGR FPUs. This technique has a potential role in the assessment of human pregnancy.