Maternal and fetal outcomes after planned cesarean or vaginal delivery in twin pregnancy: a comparison between 2 third level birth centers.

BACKGROUND: Twin pregnancy is associated with higher risks of adverse perinatal outcomes for both the mother and the babies. Among the many challenges in the follow-up of twin pregnancies, the mode of delivery is the last but not the least decision to be made, with the main influencing factors being amnionicity and fetal presentation. The aim of the study was to compare perinatal outcomes in two European centers using different protocols for twin birth in case of non-cephalic second twin; the Italian patients being delivered mainly by cesarean section with those in Belgium being routinely offered the choice of vaginal delivery (VD). METHODS: This was a dual center international retrospective observational study. The population included 843 women with a twin pregnancy ≥ 32 weeks (dichorionic or monochorionic diamniotic pregnancies) and a known pregnancy outcome. The population was stratified according to chorionicity. Demographic and pregnancy data were reported per pregnancy, whereas neonatal outcomes were reported per fetus. We used multiple logistic regression models to adjust for possible confounding variables and to compute the adjusted odds ratio (adjOR) for each maternal or neonatal outcome. RESULTS: The observed rate of cesarean delivery was significantly higher in the Italian cohort: 85% for dichorionic pregnancies and 94.4% for the monochorionic vs 45.2% and 54.4% respectively in the Belgian center (p-value < 0.001). We found that Belgian cohort showed significantly higher rates of NICU admission, respiratory distress at birth and Apgar score of < 7 after 5 min. Despite these differences, the composite severe adverse outcome was similar between the two groups. CONCLUSION: In this study, neither the presentation of the second twin nor the chorionicity affected maternal and severe neonatal outcomes, regardless of the mode of delivery in two tertiary care centers, but VD was associated to a poorer short-term neonatal outcome.

A simulation study to assess the potential benefits of MRI-based fetal weight estimation as a second-line test for suspected macrosomia.

OBJECTIVE: To simulate the outcomes of Boulvain's trial by using magnetic resonance imaging (MRI) for estimated fetal weight (EFW) as a second-line confirmatory imaging. STUDY DESIGN: Data derived from the Boulvain's trial and the study PREMACRO (PREdict MACROsomia) were used to simulate a 1000-patient trial. Boulvain's trial compared induction of labor (IOL) to expectant management in suspected macrosomia, whereas PREMACRO study compared the performance of ultrasound-EFW (US-EFW) and MRI-EFW in the prediction of birthweight. The primary outcome was the incidence of significant shoulder dystocia (SD). Cesarean delivery (CD), hyperbilirubinemia (HB), and IOL at < 39 weeks of gestation (WG) were selected as secondary outcomes. A subgroup analysis of the Boulvain's trial was performed to estimate the incidence of the primary and secondary outcomes in the true positive and false positive groups for the two study arms. Sensitivity, specificity, positive and negative predictive values (PPV, NPV) for the prediction of macrosomia by MRI-EFW at 36 WG were calculated, and a decision tree was constructed for each outcome. RESULTS: The PPV of US-EFW for the prediction of macrosomia in the PREMACRO trial was 56.3 %. MRI-EFW was superior to US-EFW as a predictive tool resulting in lower rates of induction for false-positive cases. Repeating Boulvain's trial using MRI-EFW as a second-line test would result in similar rates of SD (relative risk [RR]:0.36), CD (RR:0.84), and neonatal HB (RR:2.6), as in the original trial. Increasing the sensitivity and specificity of MRI-EFW resulted in a similar relative risk for SD as in Boulvain's trial, but with reduced rates of IOL < 39 WG, and improved the RR of CD in favor of IOL. We found an inverse relationship between IOL rate and incidence of SD for both US-EFW and MRI-EFW, although overall rates of IOL, CD, and neonatal HB would be lower with MRI-derived estimates of fetal weight. CONCLUSION: The superior accuracy of MRI-EFW over US-EFW for the diagnosis of macrosomia could result in lower rates of IOL without compromising the relative advantages of the intervention but fails to demonstrate a significant benefit to justify a replication of the original trial using MRI-EFW as a second-line test.

Postmortem imaging of fetuses at early gestations: A comparison of microfocus computed tomography with postmortem magnetic resonance at 9.4 T and postmortem ultrasound.

OBJECTIVE: To compare the diagnostic performance of postmortem ultrasound (PMUS), 9.4 T magnetic resonance imaging (MRI) and microfocus computed tomography (micro-CT) for the examination of early gestation fetuses. METHOD: Eight unselected fetuses (10-15 weeks gestational age) underwent at least 2 of the 3 listed imaging examinations. Six fetuses underwent 9.4 T MRI, four underwent micro-CT and six underwent PMUS. All operators were blinded to clinical history. All imaging was reported according to a prespecified template assessing 36 anatomical structures, later grouped into five regions: brain, thorax, heart, abdomen and genito-urinary. RESULTS: More anatomical structures were seen on 9.4 T MRI and micro-CT than with PMUS, with a combined frequency of identified structures of 91.9% and 69.7% versus 54.5% and 59.6 (p < 0.001; p < 0.05) respectively according to comparison groups. In comparison with 9.4 T MRI, more structures were seen on micro-CT (90.2% vs. 83.3%, p < 0.05). Anatomical structures were described as abnormal on PMUS in 2.7%, 9.4 T MRI in 6.1% and micro-CT 7.7% of all structures observed. However, the accuracy test could not be calculated because conventional autopsy was performed on 6 fetuses of that only one structure was abnormal. CONCLUSION: Micro-CT appears to offer the greatest potential as an imaging adjunct or non-invasive alternative for conventional autopsies in early gestation fetuses.

Performance of fetal ultrasound and magnetic resonance imaging in predicting birthweight according to the test-to-delivery interval: A cohort study.

OBJECTIVE: To assess the influence of the test-to-delivery interval (TDI) on the performance of ultrasound (US) and magnetic resonance imaging (MRI) for predicting birthweight (BW). STUDY DESIGN: This is a secondary analysis of a prospective, single center, blinded cohort study that compared MRI and US for the prediction of BW ≥ 95th percentile in singleton pregnancies. Patients that were included in the initial study underwent US and MRI for estimation of fetal weight between 36 + 0/7 and 36 + 6/7 weeks of gestation (WG). The primary outcome of the current study was to report the changes of US and MRI sensitivity and specificity in the prediction of BW > 95th percentile, BW > 90th percentile, BW < 10th percentile, and BW < 5th percentile, according to the TDI. The secondary outcome was to represent the performance of both tools in the prediction of BW > 90th percentile when TDI is<2 weeks, between 2 and 4 weeks, and>4 weeks. Receiver operating characteristic (ROC) curves were constructed accordingly. RESULTS: 2378 patients were eligible for final analysis. For the prediction of BW > 95th or 90th percentile, the sensitivity of MRI remains high until 2 weeks, and it decreases slowly between 2 and 4 weeks, in contrast to the sensitivity of US which decreases rapidly 2 weeks after examination (p < 0.001). For the prediction of BW < 10th or 5th percentile, the sensitivity of both tools decreases in parallel between 1 and 2 weeks. The specificities of both tools remain high from examination till delivery. These findings are reproducible with the use of the antenatal customized and the postnatal national growth charts. CONCLUSION: The performance of MRI in the prediction of BW, especially in large-for-gestational age, is maximal when delivery occurs within two weeks of the examination, decreasing slightly thereafter, in contrast with the performance of US which decreases drastically over time.

Learning curve for fetal postmortem ultrasound.

OBJECTIVE: To determine the learning curve of fetal postmortem ultrasound (PMUS) and evaluate the evolution of its diagnostic performance over the past 8 years. METHODS: PMUS was performed by two fetal medicine specialists and two experts on 100 unselected fetuses of 12-38 weeks of gestation in a prospective, double-blind manner. 21 pre-defined internal structures were analyzed consecutively by the trainee alone and the expert, with a comparison of diagnosis and immediate feedback. The learning curves for examination duration, non-recognition of structures and final diagnoses were computed using cumulative summation analysis. Secondly, the expert PMUS diagnostic accuracy using autopsy as the gold standard was compared to the previously published data. RESULTS: The trainees reached expert level of PMUS at 28-36 cases for examination duration (12.1 ± 5.2 min), non-diagnostic rate (6.5%, 137/2100), and abnormality diagnosis. In a group of 33 fetuses ≥20 weeks who had an autopsy, the experts PMUS performance was improved after 8 years with a reduction of all organs non-diagnostic rate (6.5 %VS 11.4%, p < 0.01) and higher sensitivity for the heart (100% VS 40.9%, p < 0.01) and the abdomen (100%VS 56.5%, p < 0.05). CONCLUSION: PMUS offers a short learning curve for fetal medicine specialists and on-going improvement of diagnostic accuracy over time.

Reducing macrosomia-related birth complications in primigravid women: ultrasound- and magnetic resonance imaging-based models.

BACKGROUND: Many complications increase with macrosomia, which is defined as birthweight of ≥4000 g. The ability to estimate when the fetus would exceed 4000 g could help to guide decisions surrounding the optimal timing of delivery. To the best of our knowledge, there is no available tool to perform this estimation independent of the currently available growth charts. OBJECTIVE: This study aimed to develop ultrasound- and magnetic resonance imaging-based models to estimate at which gestational age the birthweight would exceed 4000 g, evaluate their predictive performance, and assess the effect of each model in reducing adverse outcomes in a prospectively collected cohort. STUDY DESIGN: This study was a subgroup analysis of women who were recruited for the estimation of fetal weight by ultrasound and magnetic resonance imaging at 36 0/7 to 36 6/7 weeks of gestation. Primigravid women who were eligible for normal vaginal delivery were selected. Multiparous patients, patients with preeclampsia spectrum, patients with elective cesarean delivery, and patients with contraindications for normal vaginal delivery were excluded. Of note, 2 linear models were built for the magnetic resonance imaging- and ultrasound-based models to predict a birthweight of ≥4000 g. Moreover, 2 formulas were created to predict the gestational age at which birthweight will reach 4000 g (predicted gestational age); one was based on the magnetic resonance imaging model, and the second one was based on the ultrasound model. This study compared the adverse birth outcomes, such as intrapartum cesarean delivery, operative vaginal delivery, anal sphincter injury, postpartum hemorrhage, shoulder dystocia, brachial plexus injury, Apgar score of <7 at 5 minutes of life, neonatal intensive care unit admission, and intracranial hemorrhage in the group of patients who delivered after the predicted gestational age according to the magnetic resonance imaging-based or the ultrasound-based models with those who delivered before the predicted gestational age by each model, respectively. RESULTS: Of 2378 patients, 732 (30.8%) were eligible for inclusion in the current study. The median gestational age at birth was 39.86 weeks of gestation (interquartile range, 39.00-40.57), the median birthweight was 3340 g (interquartile range, 3080-3650), and 63 patients (8.6%) had a birthweight of ≥4000 g. Prepregnancy body mass index, geographic origin, gestational age at birth, and fetal body volume were retained for the optimal magnetic resonance imaging-based model, whereas maternal age, gestational diabetes mellitus, diabetes mellitus type 1 or 2, geographic origin, fetal gender, gestational age at birth, and estimated fetal weight were retained for the optimal ultrasound-based model. The performance of the first model was significantly better than the second model (area under the curve: 0.98 vs 0.89, respectively; P<.001). The group of patients who delivered after the predicted gestational age by the first model (n=40) had a higher risk of cesarean delivery, postpartum hemorrhage, and shoulder dystocia (adjusted odds ratio: 3.15, 4.50, and 9.67, respectively) than the group who delivered before this limit. Similarly, the group who delivered after the predicted gestational age by the second model (n=25) had a higher risk of cesarean delivery and postpartum hemorrhage (adjusted odds ratio: 5.27 and 6.74, respectively) than the group who delivered before this limit. CONCLUSION: The clinical use of magnetic resonance imaging- and ultrasound-based models, which predict a gestational age at which birthweight will exceed 4000 g, may reduce macrosomia-related adverse outcomes in a primigravid population. The magnetic resonance imaging-based model is better for the identification of the highest-risk patients.

Chest CT scan predictors of intensive care unit admission in hospitalized pregnant women with COVID-19: a case-control study.

PURPOSE: To investigate the role of chest computed tomography (CT) scan in the prediction of admission of pregnant women with COVID-19 into intensive care unit (ICU). METHODS: This was a single-center retrospective case-control study. We included pregnant women diagnosed with COVID-19 by reverse transcriptase polymerase chain reaction between February 2020 and July 2021, requiring hospital admission due to symptoms, who also had a CT chest scan at presentation. Patients admitted to the ICU (case group) were compared with patients who did not require ICU admission (control group). The CT scans were reported by an experienced radiologist, blinded to the patient's course and outcome, aided by an artificial intelligence software. Total CT scan score, chest CT severity score (CT-SS), total lung volume (TLV), infected lung volume (ILV), and infected-to-total lung volume ratio (ILV/TLV) were calculated. Receiver operating characteristic curves were constructed to test the sensitivity and specificity of each parameter. RESULTS: 8/28 patients (28.6%) required ICU admission. These also had lower TLV, higher ILV, and ILV/TLV. The area under the curve (AUC) for these three parameters was 0.789, 0.775, and 0.763, respectively. TLV, ILV, and ILV/TLV had good sensitivity (62.5%, 87.5%, and 87.5%, respectively) and specificity (84.2%, 70%, and 73.7%, respectively) for predicting ICU admission at the following selected thresholds: 2255 mL, 319 mL, and 14%, respectively. The performance of CT-SS, CT scan score, and ILV/TLV in predicting ICU admission was comparable. CONCLUSION: TLV, ILV, and ILV/TLV as measured by an artificial intelligence software on chest CT, may predict ICU admission in hospitalized pregnant women, symptomatic for COVID-19.

The impact of different growth charts on birthweight prediction: obstetrical ultrasound vs magnetic resonance imaging.

BACKGROUND: The estimation of fetal weight by fetal magnetic resonance imaging is a simple and rapid method with a high sensitivity in predicting birthweight in comparison with ultrasound. Several national and international growth charts are currently in use, but there is substantial heterogeneity among these charts due to variations in the selected populations from which they were derived, in methodologies, and in statistical analysis of data. OBJECTIVE: This study aimed to compare the performance of magnetic resonance imaging and ultrasound for the prediction of birthweight using 3 commonly used fetal growth charts: the INTERGROWTH-21st Project, World Health Organization, and Fetal Medicine Foundation charts. STUDY DESIGN: Data derived from a prospective, single-center, blinded cohort study that compared the performance of magnetic resonance imaging and ultrasound between 36+0/7 and 36+6/7 weeks of gestation for the prediction of birthweight ≥95th percentile were reanalyzed. Estimated fetal weight was categorized as above or below the 5th, 10th, 90th, and 95th percentile according to the 3 growth charts. Birthweight was similarly categorized according to the birthweight standards of each chart. The performances of ultrasound and magnetic resonance imaging for the prediction of birthweight <5th, <10th, >90th, and >95th percentile using the different growth charts were compared. Data were analyzed with R software, version 4.1.2. The comparison of sensitivity and specificity was done using McNemar and exact binomial tests. P values <.05 were considered statistically significant. RESULTS: A total of 2378 women were eligible for final analysis. Ultrasound and magnetic resonance imaging were performed at a median gestational age of 36+3/7 weeks, delivery occurred at a median gestational age of 39+3/7 weeks, and median birthweight was 3380 g. The incidences of birthweight <5th and <10th percentiles were highest with the Fetal Medicine Foundation chart and lowest with the INTERGROWTH-21st chart, whereas the incidences of birthweight >90th and >95th percentiles were lowest with the Fetal Medicine Foundation chart and highest with the INTERGROWTH-21st chart. The sensitivity of magnetic resonance imaging with an estimated fetal weight >95th percentile in the prediction of birthweight >95th percentile was significantly higher than that of ultrasound across the 3 growth charts; however, its specificity was slightly lower than that of ultrasound. In contrast, the sensitivity of magnetic resonance imaging with an estimated fetal weight <10th percentile for predicting birthweight <10th percentile was significantly lower than that of ultrasound in the INTERGROWTH-21st and Fetal Medicine Foundation charts, whereas the specificity and positive predictive value of magnetic resonance imaging were significantly higher than those of ultrasound for all 3 charts. Findings for the prediction of birthweight >90th percentile were close to those of birthweight >95th percentile, and findings for the prediction of birthweight <5th percentile were close to those of birthweight <10th percentile. CONCLUSION: The sensitivity of magnetic resonance imaging is superior to that of ultrasound for the prediction of large for gestational age fetuses and inferior to that of ultrasound for the prediction of small for gestational age fetuses across the 3 different growth charts. The reverse is true for the specificity of magnetic resonance imaging in comparison with that of ultrasound.

Pregnancy outcomes in breech presentation at term: a comparison between 2 third level birth center protocols.

BACKGROUND: Medical literature supports planned cesarean delivery for breech presentation at term because of observed reductions in neonatal morbidity and mortality compared with vaginal breech delivery. OBJECTIVE: This study aimed to compare perinatal outcomes of singleton pregnancies with breech presentation at term according to the different delivery protocols of 2 teaching hospitals, where vaginal breech delivery (protocol 1) or cesarean delivery (protocol 2) is routinely offered, respectively. STUDY DESIGN: A retrospective matched cohort study was conducted between January 2015 and May 2021. A total of 1079 women were eligible for analysis. After matching for possible confounding factors, the final analysis was performed on 257 patients in each group. The primary outcomes were a composite of adverse obstetrical outcomes and a composite of neonatal adverse outcomes. RESULTS: Overall, 1079 women were eligible for analysis. After matching for possible confounding factors, the final analysis was performed on 257 patients in each group. The composite of adverse obstetrical outcomes was similar in the 2 groups (24.1% vs 24.5%; P=1.000); however, the composite of neonatal adverse outcomes was significantly higher for protocol 1 (17.9% vs 1.2%; P<.001). No neonatal death or birth trauma was reported in either group. The rates of neonatal intensive care unit admission (4.3% vs 0.4%; P=.004), respiratory distress at birth (17.5% vs 1.2%; P<.001), and Apgar scores of <7 after 5 minutes (5.8% vs 0.4%; P<.001) were significantly higher for protocol 1. CONCLUSION: Short-term, nonsevere adverse neonatal outcomes were significantly increased in the protocol 1 group. These must be balanced against the possible negative effects of cesarean delivery on long-term infant and maternal health.

Foetal loss after chorionic villus sampling and amniocentesis in twin pregnancies: A multicentre retrospective cohort study.

OBJECTIVE: We aimed to determine foetal losses for DCDA and MCDA twins following transabdominal CVS or amniocentesis performed <22+0  weeks. METHODS: Retrospective cohort study conducted in the UK and Belgium 01/01/00-01/06/20. Cases with unknown chorionicity, monochorionic complications or complex procedures were excluded. Uncomplicated DCDA and MCDA twins without invasive procedures were identified as controls. We reported foetal losses <24+0  weeks and losses of genetically and structurally normal foetuses. RESULTS: Outcomes were compared for DCDA foetuses; 258 after CVS with 3406 controls, 406 after amniocentesis with 3390 controls plus MCDA foetuses, 98 after CVS with 1124 controls, and 160 after amniocentesis with 1122 controls. There were more losses <24+0  weeks with both procedures in DCDA (CVS RR 5.54 95% CI 3.38-9.08, amniocentesis RR 2.36 95% CI 1.22-4.56) and MCDA twins (CVS RR 5.14 95% CI 2.51-10.54, amniocentesis RR 7.01 95% CI 3.86-12.74). Losses of normal foetuses were comparable to controls (DCDA CVS RR 0.39 95% CI 0.05-2.83, DCDA amniocentesis RR 1.16 95% CI 0.42-3.22, MCDA CVS RR 2.3 95% CI 0.71-7.56, and MCDA amniocentesis RR 1.93 95% CI 0.59-6.38). CONCLUSIONS: This study indicates increased foetal losses for DCDA and MCDA twins following CVS and amniocentesis with uncertain risk to normal foetuses.

Prenatal Diagnosis of a Liver Mass by Tru-Cut® Biopsy.

A 32-year-old woman, gravida 2 para 1 at 33 weeks' gestation, was referred for a third opinion regarding a large fetal liver mass. The couple sought approval for a termination of pregnancy, following a differential diagnosis of hepatoblastoma. A specialized ultrasound and fetal magnetic resonance imaging were repeated in our unit and the results were consistent with a presumed diagnosis of hemangioma. A Tru-Cut® (Merit Medical, Utah, USA) liver biopsy was performed confirming a benign hemangioma and the couple opted to continue with the pregnancy.

Antenatal insulin therapy in gestational diabetes mellitus: validation of the new Brugmann scores.

BACKGROUND: Following the adoption of the International Association of Diabetes and Pregnancy Study Group (IADPSG) criteria for gestational diabetes mellitus (GDM) diagnosis by the World Health Organization (WHO) in 2014, many investigators have tried to identify independent risk factors for antenatal insulin therapy (AIT). The purpose of the current study is to build and validate a score that stratifies patients according to their need for AIT. METHODS: All pregnant women diagnosed with GDM according to the IADPSG definition were included. Group 1 comprised patients of 2018, and group 2 comprised patients of 2019. Each group was divided into two subgroups: subgroup A comprised patients diagnosed according to the 75-g oral glucose tolerance test (OGTT), and subgroup B comprised patients diagnosed according to fasting plasma glucose (FPG). RESULTS: A total of 1298 patients were included; 19.3% of those diagnosed by OGTT and 40.9% by FPG required AIT. The risk for AIT was stratified as low, moderate, and high. Brugmann FPG score comprised six risk factors and Brugmann OGTT score 12. Higher scores were associated with higher risk for AIT. The use of these scores in the two subgroups of group 2 showed no statistical differences compared to group 1. CONCLUSIONS: Both Brugmann FPG and OGTT scores may be useful to stratify patients with GDM according to their need for AIT. Future studies should be conducted to prospectively validate these scores, and to examine whether or not using oral anti-hyperglycemic agents in a high-risk group may decrease the need for AIT.

Evaluation of the new expert consensus-based definition of selective fetal growth restriction in monochorionic pregnancies.

OBJECTIVE: To compare the outcomes of a cohort of monochorionic pregnancies with selective fetal growth restriction (sFGR) diagnosed according to the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) definition published in 2015 with a cohort considered as sFGR according to new expert consensus-based diagnostic parameters published in 2019. METHODS: This was a retrospective study, conducted between January 1st 2010 and July 30th 2019. We reviewed the medical records of all the monochorionic pregnancies followed in our center including perinatal outcomes. Pregnancies complicated by fetal anomalies, infection, twin-twin transfusion syndrome, twin anaemia-polycythemia sequence and twin reversed arterial perfusion sequence were excluded. Patients were grouped according to the 2015 ISUOG definition into: normal (Group 1), sFGR (Group 2), and monochorionic pregnancies with abnormal growth that did not fulfill the full criteria for sFGR (Group 3). After the initial classifications were made, an additional group, was created, including all pregnancies reclassified as sFGR according to the 2019 expert consensus parameters (Group 4). RESULTS: During the study period, 291 monochorionic pregnancies were followed in our center, 132 of whom were eligible for inclusion in the final analysis. The prevalence of sFGR increased from 17.4% to 26.5% after applying the expert consensus-based parameters to the study population. Compared to group 1, group 2 had higher rates of emergency cesarean, neonatal intensive care admissions, invasive and noninvasive ventilation, surfactant use, metabolic disorders and lower gestational ages at birth. In contrast, the neonatal outcomes of Groups 1 and 4 were not significantly different. CONCLUSION: When the 2019 consensus-based diagnostic parameters for sFGR were applied to our study population, the number of sFGR cases increased by over 50%, without any improvements in perinatal outcomes. Larger prospective studies are needed to examine the potential clinical implications of these new parameters for sFGR in monochorionic pregnancies.

Fetal magnetic resonance imaging at 36 weeks predicts neonatal macrosomia: the PREMACRO study.

BACKGROUND: Large-for-gestational-age fetuses are at increased risk of perinatal morbidity and mortality. Magnetic resonance imaging seems to be more accurate than ultrasound in the prediction of macrosomia; however, there is no well-powered study comparing magnetic resonance imaging with ultrasound in routine pregnancies. OBJECTIVE: This study aimed to prospectively compare estimates of fetal weight based on 2-dimensional ultrasound and magnetic resonance imaging with actual birthweights in routine pregnancies. STUDY DESIGN: From May 2016 to February 2019, women received counseling at the 36-week clinic. Written informed consent was obtained for this Ethics Committee-approved study. In this prospective, single-center, blinded study, pregnant women with singleton pregnancies between 36 0/7 and 36 6/7 weeks' gestation underwent both standard evaluation of estimated fetal weight with ultrasound according to Hadlock et al and magnetic resonance imaging according to the formula developed by Baker et al, based on the measurement of the fetal body volume. Participants and clinicians were aware of the results of the ultrasound but blinded to the magnetic resonance imaging estimates. Birthweight percentile was considered as the gold standard for the ultrasound and magnetic resonance imaging-derived percentiles. The primary outcome was the area under the receiver operating characteristic curve for the prediction of large-for-gestation-age neonates with birthweights of ≥95th percentile. Secondary outcomes included the comparative prediction of large-for-gestation-age neonates with birthweights of ≥90th, 97th, and 99th percentiles and small-for-gestational-age neonates with birthweights of ≤10th, 5th, and 3rd percentiles for gestational age and maternal and perinatal complications. RESULTS: Of 2914 women who were initially approached, results from 2378 were available for analysis. Total fetal body volume measurements were possible for all fetuses, and the time required to perform the planimetric measurements by magnetic resonance imaging was 3.0 minutes (range, 1.3-5.6). The area under the receiver operating characteristic curve for the prediction of a birthweight of ≥95th percentile was 0.985 using prenatal magnetic resonance imaging and 0.900 using ultrasound (difference=0.085, P<.001; standard error, 0.020). For a fixed false-positive rate of 5%, magnetic resonance imaging for the estimation of fetal weight detected 80.0% (71.1-87.2) of birthweight of ≥95th percentile, whereas ultrasound for the estimation of fetal weight detected 59.1% (49.0-68.5) of birthweight of ≥95th percentile. The positive predictive value was 42.6% (37.8-47.7) for the estimation of fetal weight using magnetic resonance imaging and 35.4% (30.1-41.1) for the estimation of fetal weight using ultrasound, and the negative predictive value was 99.0% (98.6-99.3) for the estimation of fetal weight using magnetic resonance imaging and 98.0% (97.6-98.4) for the estimation of fetal weight using ultrasound. For a fixed false-positive rate of 10%, magnetic resonance imaging for the estimation of fetal weight detected 92.4% (85.5-96.7) of birthweight of ≥95th percentile, whereas ultrasound for the estimation of fetal weight detected 76.2% (66.9-84.0) of birthweight of ≥95th percentile. The positive predictive value was 29.9% (27.2-32.8) for the estimation of fetal weight using magnetic resonance imaging and 26.2% (23.2-29.4) for the estimation of fetal weight using ultrasound, and the negative predictive value was 99.6 (99.2-99.8) for the estimation of fetal weight using magnetic resonance imaging and 98.8 (98.4-99.2) for the estimation of fetal weight using ultrasound. The area under the receiver operating characteristic curves for the prediction of large-for-gestational-age neonates with birthweights of ≥90th, 97th, and 99th percentiles and small-for-gestational-age neonates with birthweights of ≤10th, 5th, and 3rd percentiles was significantly larger in prenatal magnetic resonance imaging than in ultrasound (P<.05 for all). CONCLUSION: At 36 weeks' gestation, magnetic resonance imaging for the estimation of fetal weight performed significantly better than ultrasound for the estimation of fetal weight in the prediction of large-for-gestational-age neonates with birthweights of ≥95th percentile for gestational age and all other recognized cutoffs for large-for-gestational-age and small-for-gestational-age neonates (P<.05 for all).

Severe Acute Respiratory Syndrome Coronavirus 2 and Pregnancy Outcomes According to Gestational Age at Time of Infection.

We conducted an international multicenter retrospective cohort study, PregOuTCOV, to examine the effect of gestational age at time of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on obstetric and neonatal outcomes. We included all singleton pregnancies with a live fetus at 10 weeks' gestation in which pregnancy outcomes were known. The exposed group consisted of patients infected with SARS-CoV-2, whereas the unexposed group consisted of all remaining patients during the same period. Primary outcomes were defined as composite adverse obstetric outcomes and composite adverse neonatal outcomes. Of 10,925 pregnant women, 393 (3.60%) were infected with SARS-CoV-2 (exposed group). After matching for possible confounders, we identified statistically significant increases in the exposed group of composite adverse obstetric outcomes at >20 weeks' gestation and of composite adverse neonatal outcomes at >26 weeks' gestation (p<0.001). Vaccination programs should target women early in pregnancy or before conception, if possible.

Antenatal management and neonatal outcomes of monochorionic twin pregnancies in a tertiary teaching hospital: a 10-year review.

Monochorionic (MC) pregnancy is a high risk pregnancy with well-defined specific complications, such as twin-to-twin transfusion syndrome (TTTS) and twin anaemia-polycythaemia sequence (TAPS). Laser photocoagulation (LPC) is an effective treatment for both complications. In the current retrospective study, we determined the incidence of MC pregnancy complications in a tertiary care centre during a 10-year period. Single foetal death (FD) beyond 14 weeks' gestation was significantly higher when complicated by either TTTS, TAPS or selective foetal growth restriction (21.4%, 16.7% and 9.1% versus 1.6%, p<.001, p=.02 and p=.04, respectively). We also demonstrated that twins' weight discordance >20% is an independent risk factor for single or double FD after LPC. Consequently, prior to LPC, patients should be counselled that early diagnosis of TTTS, advanced Quintero stages and weight discordances >20% are potential risk factors for FD. Further studies are needed to identify additional risk factors for TTTS and TAPS outcome after LPC.Impact StatementWhat is already known on this subject? Monochorionic (MC) pregnancy is a high risk pregnancy with well-defined specific complications, such as twin-twin transfusion syndrome (TTTS) and twin anaemia-polycythaemia sequence (TAPS). Laser photocoagulation (LPC) is an effective treatment for both complications.What the results of this study add? The results of the current study determined the incidence of MC pregnancy complications in a tertiary care centre in Brussels, and identified that twins' weight discordance >20% is an independent risk factor for single or double foetal death after LPC.What the implications are of these findings for clinical practice and/or further research? Prior to laser coagulation, patients should be counselled that early diagnosis of TTTS, Quintero stages 3 or 4 and weight discordances >20% are potential risk factors for foetal demise. Further studies are needed to identify additional risk factors for TTTS and TAPS outcome after LPC.

Impact of the delay between fetal death and delivery on the success of postmortem ultrasound following termination of pregnancy.

OBJECTIVE: To evaluate the impact of the delay between fetal death and delivery on the nondiagnostic rates of post-mortem ultrasound (PM-US), following the termination of pregnancy (TOP). METHODS: We reviewed 204 cases of fetal two-dimensional PM-US performed in our center as part of a post-mortem imaging research program, over the last 5 years. Informed consent was obtained from the parents for all cases. PM-US was performed and reported according to a prespecified template with operators blinded to the prenatal diagnosis. In order to calculate the precise delay between the fetal death and the delivery, we included 107 fetal TOP's ≥ 20 weeks of gestational age (GA), where feticide was performed using an injection of lidocaine 2% prior to induction of labor. Logistic regression analysis was conducted to analyze the impact of delay between fetal death and delivery (in hours), the GA at TOP (in weeks) and the method of feticide (intracardiac versus intraumbilical injection) on the PMUS nondiagnostic rates. RESULTS: The delay between fetal death and delivery increased the nondiagnostic rate of PM-US for cerebral examinations (OR: 1.04, IC 95%: 1.01-1.08, p < .05). For PM-US cardiac examination, the delay did not influence the nondiagnostic rate. However, GA (OR: 1.25, IC 95%: 1.10-1.46, p < .01) and feticide with intracardiac injection (OR: 4.29, IC 95%: 1.68-12.02, p < .01) were associated with higher nondiagnostic rates. For noncardiac thoracic and abdominal examinations, none of the studied variables influenced the nondiagnostic rate. CONCLUSION: The success rate of cerebral PM-US was influenced by the delay between fetal death and delivery, suggesting a possible advantage of performing the feticide closer to the delivery where the examination of the brain is planned. For cardiac abnormalities, feticide by intraumbilical, rather than intracardiac injection improves diagnostic rates of cardiac PM-US.

Post-Laser Twin Anemia Polycythemia Sequence: Diagnosis, Management, and Outcome in an International Cohort of 164 Cases.

The aim of this study was to investigate the management and outcome in the post-laser twin anemia polycythemia sequence (TAPS). Data of the international TAPS Registry, collected between 2014 and 2019, were used for this study. The primary outcomes were perinatal mortality and severe neonatal morbidity. Secondary outcomes included a risk factor analysis for perinatal mortality and severe neonatal morbidity. A total of 164 post-laser TAPS pregnancies were included, of which 92% (151/164) were diagnosed antenatally and 8% (13/164) postnatally. The median number of days between laser for TTTS and detection of TAPS was 14 (IQR: 7-28, range: 1-119). Antenatal management included expectant management in 43% (62/151), intrauterine transfusion with or without partial exchange transfusion in 29% (44/151), repeated laser surgery in 15% (24/151), selective feticide in 7% (11/151), delivery in 6% (9/151), and termination of pregnancy in 1% (1/151). The median gestational age (GA) at birth was 31.7 weeks (IQR: 28.6-33.7; range: 19.0-41.3). The perinatal mortality rate was 25% (83/327) for the total group, 37% (61/164) for donors, and 14% (22/163) for recipients (p < 0.001). Severe neonatal morbidity was detected in 40% (105/263) of the cohort and was similar for donors (43%; 51/118) and recipients (37%; 54/145), p = 0.568. Independent risk factors for spontaneous perinatal mortality were antenatal TAPS Stage 4 (OR = 3.4, 95%CI 1.4-26.0, p = 0.015), TAPS donor status (OR = 4.2, 95%CI 2.1-8.3, p < 0.001), and GA at birth (OR = 0.8, 95%CI 0.7-0.9, p = 0.001). Severe neonatal morbidity was significantly associated with GA at birth (OR = 1.5, 95%CI 1.3-1.7, p < 0.001). In conclusion, post-laser TAPS most often occurs within one month after laser for TTTS, but may develop up to 17 weeks after initial surgery. Management is mostly expectant, but varies greatly, highlighting the lack of consensus on the optimal treatment and heterogeneity of the condition. Perinatal outcome is poor, particularly due to the high rate of perinatal mortality in donor twins.