Postpartum cervical length as a predictor of subsequent preterm birth-novel insights on an old enigma.

BACKGROUND: Preterm birth poses one of the biggest challenge in modern obstetrics. Prediction of preterm birth has previously been based on patient history of preterm birth, short cervical length around midtrimester, and additional maternal risk factors. Little is known about cervical length and physiology during the postpartum period and any associations between postpartum cervical features and subsequent preterm birth. OBJECTIVE: This study aimed to determine the feasibility and utility of postpartum cervical length measurements in prediction of subsequent spontaneous preterm birth. STUDY DESIGN: This was a prospective cohort study in a single tertiary center, conducted during a 5-year period (2017-2021). We evaluated the mean postpartum cervical length in patients after both preterm birth and term deliveries at 4 time periods: 8, 24, and 48 hours, and 6 weeks postpartum, with follow-up in their subsequent pregnancies to evaluate gestational age at delivery. The mean postpartum cervical length in different populations stratified by gestational age at delivery was assessed in phase 1 of the study, and the gestational age at subsequent delivery was assessed in phase 2. RESULTS: A total of 1384 patients participated in phase 1. Mean postpartum cervical length was significantly shorter in the preterm birth (<34 weeks' gestation) group than in the term group at 8 hours (8.4±4.2 vs 22.3±3.5 mm; P<.0001), 24 hours (13.2±3.8 vs 33.2±3.1 mm; P<.0001), and 48 hours (17.9±4.4 vs 40.2±4.2 mm; P<.0001) postpartum. There was no significant difference in mean postpartum cervical length between the preterm birth group and the term group at 8, 24, and 48 hours postpartum. Cervical length was similar between the groups at 6 weeks postpartum. A total of 891 patients participated in phase 2. The area under the curve was higher for preterm birth screening based on a history of a short postpartum cervix alone than for a history of spontaneous preterm birth alone (0.66 [95% confidence interval, 0.63-0.69] vs 0.57 [95% confidence interval, 0.54-0.61]; P<.0001). Combining both a history of spontaneous preterm birth and a short postpartum cervix resulted in additional benefit, with an area under the curve of 0.74 (95% confidence interval, 0.73-0.84; P<.0001). CONCLUSION: Postpartum cervical length measurements may assist in detecting the group of patients at higher risk of subsequent spontaneous preterm birth. It may be beneficial to consider an increased follow-up regimen and earlier interventions in this group to reduce adverse perinatal outcomes.

Impact of prenatally diagnosed congenital heart defects on outcomes and management.

Fetal echocardiogram aids in prenatal identification of neonates at high risk for congenital heart defects (CHD). Prenatal detection rates for CHD have increased with improved ultrasound technology, the use of the early fetal echocardiography, and standardization of the performance of the fetal echocardiogram. Accurate prenatal detection of CHD, particularly complex CHD, is an important contributor to improved survival rates for patients with CHD. Early detection allows for families to choose whether or not to continue with pregnancy, referral to pediatric cardiology specialists for patient education, and delivery planning. Better psychosocial supports are needed for families with CHD.

Special Report of the Society for Maternal-Fetal Medicine Placenta Accreta Spectrum Ultrasound Marker Task Force: Consensus on definition of markers and approach to the ultrasound examination in pregnancies at risk for placenta accreta spectrum.

Placenta accreta spectrum includes the full range of abnormal placental attachment to the uterus or other structures, encompassing placenta accreta, placenta increta, placenta percreta, morbidly adherent placenta, and invasive placentation. The incidence of placenta accreta spectrum has increased in recent years, largely driven by increasing rates of cesarean delivery. Prenatal detection of placenta accreta spectrum is primarily made by ultrasound and is important to reduce maternal morbidity associated with the condition. Despite a large body of research on various placenta accreta spectrum ultrasound markers and their screening performance, inconsistencies in the literature persist. In response to the need for standardizing the definitions of placenta accreta spectrum markers and the approach to the ultrasound examination, the Society for Maternal-Fetal Medicine convened a task force with representatives from the American Institute of Ultrasound in Medicine, the American College of Obstetricians and Gynecologists, the American College of Radiology, the International Society of Ultrasound in Obstetrics and Gynecology, the Society for Radiologists in Ultrasound, the American Registry for Diagnostic Medical Sonography, and the Gottesfeld-Hohler Memorial Ultrasound Foundation. The goals of the task force were to assess placenta accreta spectrum sonographic markers on the basis of available data and expert consensus, provide a standardized approach to the prenatal ultrasound evaluation of the uterus and placenta in pregnancies at risk of placenta accreta spectrum, and identify research gaps in the field. This manuscript provides information on the Placenta Accreta Spectrum Task Force process and findings.

Fetal Myocardial Function as Assessed by N-Terminal Fragment Brain Natriuretic Protein in Premature Fetuses Exposed to Intra-amniotic Inflammation.

OBJECTIVE: This study aimed to determine the relationship between fetal exposure to intra-amniotic infection/inflammation (IAI) and fetal heart ventricular function as assessed by circulatory levels of N-terminal fragment brain natriuretic protein (NT-proBNP) and the Tei index. STUDY DESIGN: We analyzed 70 samples of paired amniotic fluid (AF) and cord blood retrieved from mothers who delivered preterm at <34 weeks as follows: Yes-IAI (n = 36) and No-IAI (n = 34). IAI was diagnosed by amniocentesis and AF mass spectrometry. Fetal exposure to inflammation was determined through the evaluation of cord blood haptoglobin (Hp) switch-on status and level, and interleukin (IL)-6 levels by Western blotting and enzyme-linked immunosorbent assay, respectively. Fetal heart function was assessed by cord blood NT-proBNP immunoassay and fetal echocardiogram (Tei index). RESULTS: IAI was characterized by significantly higher levels of AF (p < 0.001) and umbilical cord IL-6 (p = 0.004). Cord blood Hp levels and frequency of switch-on status were higher in fetuses exposed to IAI (p < 0.001, both). Fetuses exposed to IAI did not have higher levels of NT-proBNP. Following correction for gestational age and race, neither cord blood NT-proBNP nor the Tei index was significantly different in fetuses with Hp switched-on status (p > 0.05, both). CONCLUSION: Fetal myocardial left ventricular function does not seem to be significantly impaired in fetuses born alive due to IAI if delivery of the fetus occurs immediately following the diagnosis of IAI.

Utility of Fetal Cardiac Axis and Cardiac Position Assessment in Predicting Neonatal Respiratory Morbidity in Fetal Congenital Lung Lesions.

OBJECTIVES: To assess the diagnostic performance of the fetal cardiac axis (CA) and/or cardiac position (CP) versus the congenital pulmonary malformation volume ratio (CVR) in predicting any and severe neonatal respiratory morbidity in fetal congenital lung lesions. METHODS: This work was an 11-year retrospective cohort study. The sensitivity, specificity, positive predictive value, and negative predictive value of CA and/or CP assessment in prediction of respiratory morbidity were calculated before 24 weeks' gestation and between 24 and 32 weeks and compared to CVR cutoffs obtained from the literature. RESULTS: Fifty-three patients were included. CA and/or CP abnormalities were present in 45% and 38% of patients before 24 weeks and between 24 and 32 weeks and were significantly more common in left- versus right-sided lesions (60% versus 17%; P = .003). The sensitivity, specificity, positive predictive value, and negative predictive value of an abnormal CA and/or CP for any and severe respiratory morbidity were 0.67, 0.61, 0.33, and 0.86 and 0.8, 0.58, 0.17, and 0.97 before 24 weeks and 0.75, 0.73, 0.45, and 0.91 and 0.8, 0.67, 0.20, and 0.97 between 24 and 32 weeks, respectively. An abnormal CA and/or CP had higher sensitivity for any respiratory morbidity compared to the CVR at 0.5 and 0.8 cutoffs both before 24 weeks and between 24 and 32 weeks (P < .05). CONCLUSIONS: An abnormal CA and/or CP before 24 weeks and between 24 and 32 weeks has higher sensitivity for the detection of any respiratory morbidity at birth compared to the CVR at both 0.5 and 0.8 cutoffs. A normal CA and CP have a high negative predictive value for excluding any respiratory morbidity at birth both before 24 weeks and between 24 and 32 weeks.

In utero Partial Exchange Transfusion Combined with in utero Blood Transfusion for Prenatal Management of Twin Anemia-Polycythemia Sequence.

Monochorionic twin pregnancies are at risk of unique complications due to placental sharing and vascular connections between placental territories assigned for each twin. Twin anemia-polycythemia sequence (TAPS) is an infrequent but potentially dangerous complication of abnormal placental vascular connections. TAPS occurs due to very-small-caliber (< 1 mm) abnormal placental vascular connections which lead to chronic anemia in the donor twin and polycythemia in the recipient twin. TAPS may occur spontaneously or following fetoscopic laser photocoagulation of communicating placental vessels for twin-twin transfusion syndrome. One of the hallmarks of TAPS is the absence of polyhydramnios and oligohydramnios. The postnatal diagnosis is based on significant hemoglobin discrepancy between the twins. Middle cerebral artery peak systolic velocity Doppler ultrasound allows for the prenatal diagnosis of TAPS. The optimal prenatal treatment and intervention timing has not been established. Here, we report 3 spontaneous TAPS cases diagnosed and managed in the prenatal period with a combination of in utero blood transfusion for the anemic twin (donor) and in utero partial exchange transfusion for the polycythemic twin (recipient). These cases contribute to the limited outcome data of this underutilized method for the management of TAPS.

Fetal Echocardiographic Measures to Improve the Prenatal Diagnosis of Coarctation of the Aorta.

The objective of this study is to identify fetal echocardiographic measures that predict postnatal coarctation of the aorta (CoA). A retrospective review of patients from 2013 to 2017 identified 13 cases of prenatal diagnosis of CoA confirmed postnatally and 14 cases of prenatal diagnosis of CoA with normal arches postnatally. There were 30 controls. Measurements were made and indices applied on all available longitudinal fetal echocardiograms for each patient. Linear mixed effects models were used to examine the between-group differences in the trajectories of the measurements. Significant differences were seen in the true CoA group for the following: smaller distal transverse arch diameter to distance between the left common carotid and left subclavian arteries (DT/LCA-LSCA) index (p = 0.04), smaller distal transverse arch diameter (p = 0.005), and longer brachiocephalic to left common carotid artery (LCA) (p = 0.004) and LCA-left subclavian artery (LSCA) distances (p < 0.0001). Additionally, the LCA/DT index trend appears to differentiate false positives from true coarctations (p < 0.03). The fetal echocardiographic DT/LCA-LSCA index, brachiocephalic-LCA distance and LCA-LSCA distance are significant predictors of postnatal coarctation. The LCA/DT index trend over time may differentiate which of those patients with prenatal concern for coarctation are more likely to develop coarctation postnatally. The use of fetal echocardiographic measures may improve prenatal detection and predication of postnatal coarctation.

Fetal Treatment 2017: The Evolution of Fetal Therapy Centers - A Joint Opinion from the International Fetal Medicine and Surgical Society (IFMSS) and the North American Fetal Therapy Network (NAFTNet).

More than 3 decades ago, a small group of physicians and other practitioners active in what they called "fetal treatment" authored an opinion piece outlining the current status and future challenges anticipated in the field. Many advances in maternal, neonatal, and perinatal care and diagnostic and therapeutic modalities have been made in the intervening years, yet a thoughtful reassessment of the basic tenets put forth in 1982 has not been published. The present effort will aim to provide a framework for contemporary redefinition of the field of fetal treatment, with a brief discussion of the necessary minimum expertise and systems base for the provision of different types of interventions for both the mother and fetus. Our goal will be to present an opinion that encourages the advancement of thoughtful practice, ensuring that current and future patients have realistic access to centers with a range of fetal therapies with appropriate expertise, experience, and subspecialty and institutional support while remaining focused on excellence in care, collaborative scientific discovery, and maternal autonomy and safety.

Magnetic Resonance Imaging and Sonography in the Diagnosis of Placental Invasion.

OBJECTIVES: To compare older and newer magnetic resonance imaging (MRI) criteria for placental invasion and to compare the sensitivity, specificity, and accuracy of MRI and sonography in determining the depth of placental invasion. METHODS: Forty pregnant patients at high risk for morbidly adherent placenta based on prenatal sonography underwent MRI evaluations. Two reviewers, who were blinded to the original MRI and sonographic interpretations, clinical history, and obstetric/pathologic findings, reviewed the MRI examinations. The MRI and sonographic scans were analyzed for the presence and depth of invasion. The MRI scans were tabulated for the presence of dark intraplacental T2 bands, bulging of the myometrium, increased vascularity, and indistinct myometrium, loss of the dark T2 myometrial/placental interface, and a thin myometrium. The obstetric/pathologic results served as the reference standards. RESULTS: Eighteen of 40 patients had a morbidly invasive placenta. The sensitivity, specificity, and accuracy of MRI and sonography were not significantly different. The accuracy rates for determining the depth of placental invasion by readers 1 and 2 were 0.65 and 0.55, respectively (P > .05). According to the Cohen κ statistic, there was a good inter-reader agreement between the MRI readers in assessing the depth of placental invasion (κ = 0.45). The features most commonly seen were dark T2 bands, bulging of the uterus, and loss of the dark T2 interface, which were all associated with the presence of placental invasion. CONCLUSIONS: The diagnosis of placental invasion remains challenging on sonography and MRI, which perform similarly. The presence of 2 or more criteria adds specificity to the diagnosis of placental invasion on MRI.

Diagnosis and treatment of fetal cardiac disease: a scientific statement from the American Heart Association.

BACKGROUND: The goal of this statement is to review available literature and to put forth a scientific statement on the current practice of fetal cardiac medicine, including the diagnosis and management of fetal cardiovascular disease. METHODS AND RESULTS: A writing group appointed by the American Heart Association reviewed the available literature pertaining to topics relevant to fetal cardiac medicine, including the diagnosis of congenital heart disease and arrhythmias, assessment of cardiac function and the cardiovascular system, and available treatment options. The American College of Cardiology/American Heart Association classification of recommendations and level of evidence for practice guidelines were applied to the current practice of fetal cardiac medicine. Recommendations relating to the specifics of fetal diagnosis, including the timing of referral for study, indications for referral, and experience suggested for performance and interpretation of studies, are presented. The components of a fetal echocardiogram are described in detail, including descriptions of the assessment of cardiac anatomy, cardiac function, and rhythm. Complementary modalities for fetal cardiac assessment are reviewed, including the use of advanced ultrasound techniques, fetal magnetic resonance imaging, and fetal magnetocardiography and electrocardiography for rhythm assessment. Models for parental counseling and a discussion of parental stress and depression assessments are reviewed. Available fetal therapies, including medical management for arrhythmias or heart failure and closed or open intervention for diseases affecting the cardiovascular system such as twin-twin transfusion syndrome, lung masses, and vascular tumors, are highlighted. Catheter-based intervention strategies to prevent the progression of disease in utero are also discussed. Recommendations for delivery planning strategies for fetuses with congenital heart disease including models based on classification of disease severity and delivery room treatment will be highlighted. Outcome assessment is reviewed to show the benefit of prenatal diagnosis and management as they affect outcome for babies with congenital heart disease. CONCLUSIONS: Fetal cardiac medicine has evolved considerably over the past 2 decades, predominantly in response to advances in imaging technology and innovations in therapies. The diagnosis of cardiac disease in the fetus is mostly made with ultrasound; however, new technologies, including 3- and 4-dimensional echocardiography, magnetic resonance imaging, and fetal electrocardiography and magnetocardiography, are available. Medical and interventional treatments for select diseases and strategies for delivery room care enable stabilization of high-risk fetuses and contribute to improved outcomes. This statement highlights what is currently known and recommended on the basis of evidence and experience in the rapidly advancing and highly specialized field of fetal cardiac care.

A comprehensive obstetric patient safety program reduces liability claims and payments.

Begun in 2003, the Yale-New Haven Hospital comprehensive obstetric safety program consisted of measures to standardize care, improve teamwork and communication, and optimize oversight and quality review. Prior publications have demonstrated improvements in adverse outcomes and safety culture associated with this program. In this analysis, we aimed to assess the impact of this program on liability claims and payments at a single institution. We reviewed liability claims at a single, tertiary-care, teaching hospital for two 5-year periods (1998-2002 and 2003-2007), before and after implementing the safety program. Connecticut statute of limitations for professional malpractice is 36 months from injury. Claims/events were classified by event-year and payments were adjusted for inflation. We analyzed data for trends as well as differences between periods before and after implementation. Forty-four claims were filed during the 10-year study period. Annual cases per 1000 deliveries decreased significantly over the study period (P < .01). Claims (30 vs 14) and payments ($50.7 million vs $2.9 million) decreased in the 5-years after program inception. Compared with before program inception, median annual claims dropped from 1.31 to 0.64 (P = .02), and median annual payments per 1000 deliveries decreased from $1,141,638 to $63,470 (P < .01). Even estimating the monetary awards for the 2 remaining open cases using the median payments for the surrounding 5 years, a reduction in the median monetary amount per case resulting in payment to the claimant was also statistically significant ($632,262 vs $216,815, P = .046). In contrast, the Connecticut insurance market experienced a stable number of claims and markedly increased cost per claim during the same period. We conclude that an obstetric safety initiative can improve liability claims exposure and reduce liability payments.

Postnatal sonographic spectrum of prenatally detected abdominal and pelvic cysts.

OBJECTIVE: The purpose of this article is to illustrate the sonographic findings of a spectrum of neonatal abdominal and pelvic cystic lesions. CONCLUSION: Neonatal abdominal and pelvic cystic lesions can arise from many organs, and they have a broad differential diagnosis. Distinctive sonographic findings may be present and can help establish the correct cause and guide proper management.

Potassium chloride-induced fetal demise: a retrospective cohort study of efficacy and safety.

OBJECTIVES: Induction of fetal demise before second-trimester termination is performed for a number of reasons. One method for inducing fetal demise is via sonographically guided intracardiac potassium chloride (KCl) injection. We performed a retrospective cohort study to determine the efficacy and safety of intracardiac KCl injection as a method of second-trimester induced fetal demise. METHODS: We reviewed records from patients who were referred for induced fetal demise from October 2002 to October 2011. We excluded patients undergoing selective fetal reduction in multiple gestations. Procedural complications, the dose of KCl, and the number of failed procedures were determined. RESULTS: Of the 192 completed procedures, 191 were successful (99.5%). The median gestational age at termination was 22 weeks (range, 15.4-24.9 weeks), and most terminations were surgical (68.0%). Major indications for termination were fetal anomalies (41.6%), unwanted pregnancy (20.8%), and aneuploidy (15.7%). The median dose of KCl was 10 mL (range, 3-40 mL). We found a significant correlation between the dose of KCl and estimated fetal weight. There was no significant correlation between the dose of KCl and body mass index or gestational age. We had 1 maternal complication of a seizure after needle placement but before KCl injection. CONCLUSIONS: Intracardiac KCl injection is an effective and safe method for induced fetal demise.

The optimal cutoff for intertwin delivery interval: A retrospective cohort study.

OBJECTIVE: To determine the cutoff of intertwin delivery intervals (IDIs) as a predictor for neonatal acidemia. METHOD: This retrospective cohort study was conducted at a single tertiary care center. Women attempting vaginal delivery of twins between 2010 and 2019 and who reached the second stage of labor were included. The cutoff point for prolonged IDI was established using a receiver operating characteristic (ROC) curve and Youden's J statistic. Maternal and neonatal outcomes were compared between short and prolonged IDI cohorts. RESULTS: A total of 461 women were included in the study. A cutoff time of 10 min was found to be the best predictor for neonatal acidemia (arterial cord pH ≤ 7.1), with a sensitivity of 90% and a specificity of 59%. Second twins delivered more than 10 min after the first twin were more likely to be acidemic and to have a 5-min Apgar score of 7 or less (13.5% vs 3.3%, P = 0.01, and 8.4% vs 3.2%, P = 0.02, respectively). An IDI of more than 10 min was also associated with increased rate of cesarean delivery and placental abruption (13.5% vs 0.8%, P < 0.001, and 3.4% vs 0.8%, P = 0.047, respectively). No other adverse maternal or neonatal outcomes were statistically significant between cohorts. CONCLUSION: An IDI of more than 10 min is associated with a higher risk for neonatal academia, with a low 5-min Apgar score, and higher cesarean delivery and placental abruption rates. These findings provide insights that are valuable when counseling and managing twin pregnancies attempting vaginal delivery. Interventions aimed at shortening the IDI should be considered to prevent adverse neonatal outcomes.

Prospective Evaluation of High Titer Autoantibodies and Fetal Home Monitoring in the Detection of Atrioventricular Block Among Anti-SSA/Ro Pregnancies.

OBJECTIVE: This prospective study of pregnant patients, Surveillance To Prevent AV Block Likely to Occur Quickly (STOP BLOQ), addresses the impact of anti-SSA/Ro titers and utility of ambulatory monitoring in the detection of fetal second-degree atrioventricular block (AVB). METHODS: Women with anti-SSA/Ro autoantibodies by commercial testing were stratified into high and low anti-52-kD and/or 60-kD SSA/Ro titers applying at-risk thresholds defined by previous evaluation of AVB pregnancies. The high-titer group performed fetal heart rate and rhythm monitoring (FHRM) thrice daily and weekly/biweekly echocardiography from 17-26 weeks. Abnormal FHRM prompted urgent echocardiography to identify AVB. RESULTS: Anti-52-kD and/or 60-kD SSA/Ro met thresholds for monitoring in 261 of 413 participants (63%); for those, AVB frequency was 3.8%. No cases occurred with low titers. The incidence of AVB increased with higher levels, reaching 7.7% for those in the top quartile for anti-60-kD SSA/Ro, which increased to 27.3% in those with a previous child who had AVB. Based on levels from 15 participants with paired samples from both an AVB and a non-AVB pregnancy, healthy pregnancies were not explained by decreased titers. FHRM was considered abnormal in 45 of 30,920 recordings, 10 confirmed AVB by urgent echocardiogram, 7 being second-degree AVB, all <12 hours from normal FHRM and within another 0.75 to 4 hours to echocardiogram. The one participant with second/third-degree and two participants with third-degree AVB were diagnosed by urgent echocardiogram >17 to 72 hours from an FHRM. Surveillance echocardiograms detected no AVB when the preceding interval FHRM recordings were normal. CONCLUSION: High-titer antibodies are associated with an increased incidence of AVB. Anti-SSA/Ro titers remain stable over time and do not explain the discordant recurrence rates, suggesting that other factors are required. Fetal heart rate and rhythm (FHRM) with results confirmed by a pediatric cardiologist reliably detects conduction abnormalities, which may reduce the need for serial echocardiograms.

Putting the "M" back in maternal-fetal medicine.

Although maternal death remains rare in the United States, the rate has not decreased for 3 decades. The rate of severe maternal morbidity, a more prevalent problem, is also rising. Rise in maternal age, in rates of obesity, and in cesarean deliveries as well as more pregnant women with chronic medical conditions all contribute to maternal mortality and morbidity in the United States. We believe it is the responsibility of maternal-fetal medicine (MFM) subspecialists to lead a national effort to decrease maternal mortality and morbidity. In doing so, we hope to reestablish the vital role of MFM subspecialists to take the lead in the performance and coordination of care in complicated obstetrical cases. This article will summarize our initial recommendations to enhance MFM education and training, to establish national standards to improve maternal care and management, and to address critical research gaps in maternal medicine.

Early brain microstructural development among preterm infants requiring caesarean section versus those delivered vaginally.

It is known that the rate of caesarean section (C-section) has been increasing among preterm births. However, the relationship between C-section and long-term neurological outcomes is unclear. In this study, we utilized diffusion tensor imaging (DTI) to characterize the association of delivery method with brain white matter (WM) microstructural integrity in preterm infants. We retrospectively analyzed the DTI scans and health records of preterm infants without neuroimaging abnormality on pre-discharge term-equivalent MRI. We applied both voxel-wise and tract-based analyses to evaluate the association between delivery method and DTI metrics across WM tracts while controlling for numerous covariates. We included 68 preterm infants in this study (23 delivered vaginally, 45 delivered via C-section). Voxel-wise and tract-based analyses revealed significantly lower fractional anisotropy values and significantly higher diffusivity values across major WM tracts in preterm infants delivered via C-section when compared to those delivered vaginally. These results may be partially, but not entirely, mediated by lower birth weight among infants delivered by C-section. Nevertheless, these infants may be at risk for delayed neurodevelopment and could benefit from close neurological follow up for early intervention and mitigation of adverse long-term outcomes.

Early brain microstructural development among preterm infants requiring caesarean section versus those delivered vaginally.

It is known that the rate of caesarean section (C-section) has been increasing among preterm births. However, the relationship between C-section and long-term neurological outcomes is unclear. In this study, we utilized diffusion tensor imaging (DTI) to characterize the association of delivery method with brain white matter (WM) microstructural integrity in preterm infants. We retrospectively analyzed the DTI scans and health records of preterm infants without neuroimaging abnormality on pre-discharge term-equivalent MRI. We applied both voxel-wise and tract-based analyses to evaluate the association between delivery method and DTI metrics across WM tracts while controlling for numerous covariates. We included 68 preterm infants in this study (23 delivered vaginally, 45 delivered via C-section). Voxel-wise and tract-based analyses revealed significantly lower fractional anisotropy values and significantly higher diffusivity values across major WM tracts in preterm infants delivered via C-section when compared to those delivered vaginally. These results may be partially, but not entirely, mediated by lower birth weight among infants delivered by C-section. Nevertheless, these infants may be at risk for delayed neurodevelopment and could benefit from close neurological follow up for early intervention and mitigation of adverse long-term outcomes.

Comparative analysis of 2-D versus 3-D ultrasound estimation of the fetal adrenal gland volume and prediction of preterm birth.

OBJECTIVE: We aim to test the hypothesis that two-dimensional (2-D) fetal adrenal gland volume (AGV) measurements offer similar volume estimates as volume calculations based on 3-D technique. METHODS: Fetal AGV was estimated by three-dimensional (3-D) ultrasound (VOCAL) in 93 women with signs/symptoms of preterm labor and 73 controls. Fetal AGV was calculated using an ellipsoid formula derived from 2-D measurements of the same blocks (0.523 × length × width × depth). Comparisons were performed by intraclass correlation coefficient (ICC), coefficient of repeatability, and Bland-Altman method. The corrected AGV (cAGV; AGV/fetal weight) was calculated for both methods and compared for prediction of preterm birth (PTB) within 7 days. RESULTS: Among 168 volumes, there was a significant correlation between 3-D and 2-D methods (ICC = 0.979; 95% confidence interval [CI]: 0.971 to 0.984). The coefficient of repeatability for the 3-D was superior to the 2-D method (intraobserver 3-D: 30.8, 2-D:57.6; interobserver 3-D:12.2, 2-D: 15.6). Based on 2-D calculations, cAGV ≥ 433 mm3/kg was best for prediction of PTB (sensitivity: 75%, 95% CI = 59 to 87; specificity: 89%, 95% CI = 82 to 94). Sensitivity and specificity for the 3-D cAGV (cutoff ≥ 420 mm3/kg) was 85% (95% CI = 70 to 94) and 95% (95% CI = 90 to 98), respectively. In receiver-operating-curve curve analysis, 3-D cAGV was superior to 2-D cAGV for prediction of PTB (z = 1.99, p = 0.047). CONCLUSION: 2-D volume estimation of fetal adrenal gland using ellipsoid formula cannot replace 3-D AGV calculations for prediction of PTB.