Multiethnic growth standards for fetal body composition and organ volumes derived from 3D ultrasonography.

BACKGROUND: A major goal of contemporary obstetrical practice is to optimize fetal growth and development throughout pregnancy. To date, fetal growth during prenatal care is assessed by performing ultrasonographic measurement of 2-dimensional fetal biometry to calculate an estimated fetal weight. Our group previously established 2-dimensional fetal growth standards using sonographic data from a large cohort with multiple sonograms. A separate objective of that investigation involved the collection of fetal volumes from the same cohort. OBJECTIVE: The Fetal 3D Study was designed to establish standards for fetal soft tissue and organ volume measurements by 3-dimensional ultrasonography and compare growth trajectories with conventional 2-dimensional measures where applicable. STUDY DESIGN: The National Institute of Child Health and Human Development Fetal 3D Study included research-quality images of singletons collected in a prospective, racially and ethnically diverse, low-risk cohort of pregnant individuals at 12 U.S. sites, with up to 5 scans per fetus (N=1730 fetuses). Abdominal subcutaneous tissue thickness was measured from 2-dimensional images and fetal limb soft tissue parameters extracted from 3-dimensional multiplanar views. Cerebellar, lung, liver, and kidney volumes were measured using virtual organ computer aided analysis. Fractional arm and thigh total volumes, and fractional lean limb volumes were measured, with fractional limb fat volume calculated by subtracting lean from total. For each measure, weighted curves (fifth, 50th, 95th percentiles) were derived from 15 to 41 weeks' using linear mixed models for repeated measures with cubic splines. RESULTS: Subcutaneous thickness of the abdomen, arm, and thigh increased linearly, with slight acceleration around 27 to 29 weeks. Fractional volumes of the arm, thigh, and lean limb volumes increased along a quadratic curvature, with acceleration around 29 to 30 weeks. In contrast, growth patterns for 2-dimensional humerus and femur lengths demonstrated a logarithmic shape, with fastest growth in the second trimester. The mid-arm area curve was similar in shape to fractional arm volume, with an acceleration around 30 weeks, whereas the curve for the lean arm area was more gradual. The abdominal area curve was similar to the mid-arm area curve with an acceleration around 29 weeks. The mid-thigh and lean area curves differed from the arm areas by exhibiting a deceleration at 39 weeks. The growth curves for the mid-arm and thigh circumferences were more linear. Cerebellar 2-dimensional diameter increased linearly, whereas cerebellar 3-dimensional volume growth gradually accelerated until 32 weeks followed by a more linear growth. Lung, kidney, and liver volumes all demonstrated gradual early growth followed by a linear acceleration beginning at 25 weeks for lungs, 26 to 27 weeks for kidneys, and 29 weeks for liver. CONCLUSION: Growth patterns and timing of maximal growth for 3-dimensional lean and fat measures, limb and organ volumes differed from patterns revealed by traditional 2-dimensional growth measures, suggesting these parameters reflect unique facets of fetal growth. Growth in these three-dimensional measures may be altered by genetic, nutritional, metabolic, or environmental influences and pregnancy complications, in ways not identifiable using corresponding 2-dimensional measures. Further investigation into the relationships of these 3-dimensional standards to abnormal fetal growth, adverse perinatal outcomes, and health status in postnatal life is warranted.

Laparoscopic Electromyography and Electrostimulation of the Gastrointestinal Tract Before Placement of Theranostic Devices.

NEED: Electrical stimulation (ES) is a promising therapy for multisegmental gastrointestinal (GI) motility disorders such as gastroparesis with slow-transit constipation or chronic intestinal pseudo-obstruction. Wireless communicating GI devices for smart sensing and ES-based motility modulation will soon be available. Before placement, a potential benefit for each GI segment must be intraoperatively assessed. TECHNICAL SOLUTION: A minimally invasive multisegmental electromyography (EMG) analysis with ES of the GI tract is required. PROOF OF CONCEPT: Two porcine experiments were performed with a laparoscopic setup. Multiple hook-needle electrodes were subserosally applied in the stomach, duodenum, jejunum, ileum, and colon. EMG signals were acquired for computer-assisted motility analysis. Gastric ES, duodenal ES, jejunal ES, ileal ES, and colonic ES were applied. NEXT STEPS: Further technological and rapid regulatory solutions are desired to initialize a clinical trial of the next generation devices in the near future. CONCLUSION: We demonstrate a laparoscopic strategy with EMG analysis and ES of multiple GI segments. Thus, GI function may be evaluated before theranostic devices are placed. Extended GI resection or organ transplantation may be delayed or even avoided in affected patients.

Obstetric Inpatient and Ultrasound Clinical Personnel Absences during the COVID-19 Pandemic in New York City.

OBJECTIVE: To review obstetric personnel absences at a hospital during the initial peak of coronavirus disease 2019 (COVID-19) infection risk in New York City from March 25 to April 21, 2020. STUDY DESIGN: This retrospective study evaluated absences at Morgan Stanley Children's Hospital. Clinical absences for (1) Columbia University ultrasonographers, (2) inpatient nurses, (3) labor and delivery operating room (OR) technicians, (4) inpatient obstetric nurse assistants, and (5) attending physicians providing inpatient obstetric services were analyzed. Causes of absences were analyzed and classified as illness, vacation and holidays, leave, and other causes. Categorical variables were compared with the chi-square test or Fisher's exact test. RESULTS: For nurses, absences accounted for 1,052 nursing workdays in 2020 (17.2% of all workdays) compared with 670 (11.1%) workdays in 2019 (p < 0.01). Significant differentials in days absent in 2020 compared with 2019 were present for (1) postpartum nurses (21.9% compared with 12.9%, p < 0.01), (2) labor and delivery nurses (14.8% compared with 10.6%, p < 0.01), and (3) antepartum nurses (10.2% compared with 7.4%, p = 0.03). Evaluating nursing assistants, 24.3% of workdays were missed in 2020 compared with 17.4% in 2019 (p < 0.01). For ultrasonographers, there were 146 absences (25.2% of workdays) in 2020 compared with 96 absences (16.0% of workdays) in 2019 (p < 0.01). The proportion of workdays missed by OR technicians was 22.6% in 2020 and 18.3% in 2019 (p = 0.25). Evaluating attending physician absences, a total of 78 workdays were missed due to documented COVID-19 infection. Evaluating the causes of absences, illness increased significantly between 2019 and 2020 for nursing assistants (42.6 vs. 57.4%, p = 0.02), OR technicians (17.1 vs. 55.9%, p < 0.01), and nurses (15.5 vs. 33.7%, p < 0.01). CONCLUSION: COVID-19 outbreak surge planning represents a major operational issue for medical specialties such as critical care due to increased clinical volume. Findings from this analysis suggest it is prudent to devise backup staffing plans. KEY POINTS: · 1) COVID-19 outbreak surge planning represents a major operational issue for obstetrics.. · 2) Inpatient obstetric volume cannot be reduced.. · 3) Staffing contingencies plans for nurses, sonographers, and physicians may be required..

Clinical and Demographic Risk Factors for COVID-19 during Delivery Hospitalizations in New York City.

OBJECTIVE: This study was aimed to review 4 weeks of universal novel coronavirus disease 2019 (COVID-19) screening among delivery hospitalizations, at two hospitals in March and April 2020 in New York City, to compare outcomes between patients based on COVID-19 status and to determine whether demographic risk factors and symptoms predicted screening positive for COVID-19. STUDY DESIGN: This retrospective cohort study evaluated all patients admitted for delivery from March 22 to April 18, 2020, at two New York City hospitals. Obstetrical and neonatal outcomes were collected. The relationship between COVID-19 and demographic, clinical, and maternal and neonatal outcome data was evaluated. Demographic data included the number of COVID-19 cases ascertained by ZIP code of residence. Adjusted logistic regression models were performed to determine predictability of demographic risk factors for COVID-19. RESULTS: Of 454 women delivered, 79 (17%) had COVID-19. Of those, 27.9% (n = 22) had symptoms such as cough (13.9%), fever (10.1%), chest pain (5.1%), and myalgia (5.1%). While women with COVID-19 were more likely to live in the ZIP codes quartile with the most cases (47 vs. 41%) and less likely to live in the ZIP code quartile with the fewest cases (6 vs. 14%), these comparisons were not statistically significant (p = 0.18). Women with COVID-19 were less likely to have a vaginal delivery (55.2 vs. 51.9%, p = 0.04) and had a significantly longer postpartum length of stay with cesarean (2.00 vs. 2.67days, p < 0.01). COVID-19 was associated with higher risk for diagnoses of chorioamnionitis and pneumonia and fevers without a focal diagnosis. In adjusted analyses, including demographic factors, logistic regression demonstrated a c-statistic of 0.71 (95% confidence interval [CI]: 0.69, 0.80). CONCLUSION: COVID-19 symptoms were present in a minority of COVID-19-positive women admitted for delivery. Significant differences in obstetrical outcomes were found. While demographic risk factors demonstrated acceptable discrimination, risk prediction does not capture a significant portion of COVID-19-positive patients. KEY POINTS: · COVID-19 symptoms were present in a minority of COVID-19-positive women admitted.. · COVID-19 symptomatology did not appear to differ before or after the apex of infection in New York.. · Demographic risk factors are unlikely to capture a significant portion of COVID-19-positive patients..

Robotic Setup Promises Consistent Effects of Multilocular Gastrointestinal Electrical Stimulation: First Results of a Porcine Study.

BACKGROUND: Electrical stimulation (ES) of several gastrointestinal (GI) segments is a promising therapeutic option for multilocular GI dysmotility, but conventional surgical access by laparotomy involves a high degree of tissue trauma. We evaluated a minimally invasive surgical approach using a robotic surgical system to perform electromyographic (EMG) recordings and ES of several porcine GI segments, comparing these data to an open surgical approach by laparotomy. MATERIALS AND METHODS: In 5 acute porcine experiments, we placed multiple electrodes on the stomach, duodenum, jejunum, ileum, and colon. Three experiments were performed with a median laparotomy and 2 others using a robotic platform. Multichannel EMGs were recorded, and ES was sequentially delivered with 4 ES parameters to the 5 target segments. We calculated pre- and poststimulatory spikes per minute (Spm) and performed a statistical Poisson analysis. RESULTS: Electrode placement was achieved in all cases without complications. Increased technical and implantation time were required to achieve the robotic electrode placement, but invasiveness was markedly reduced in comparison to the conventional approach. The highest calculated (c)Spm values were found in the poststimulatory period of the small bowel with both the conventional and robotic approaches. Six of the 20 Poisson test results in the open setup reached statistical significance and 12 were significant in the robotic experiments. CONCLUSIONS: The robotic setup was less invasive, revealed more consistent effects of multilocular ES in several GI segments, and is a promising option for future preclinical and clinical studies of GI motility disorders.

Telehealth for High-Risk Pregnancies in the Setting of the COVID-19 Pandemic.

As New York City became an international epicenter of the novel coronavirus disease 2019 (COVID-19) pandemic, telehealth was rapidly integrated into prenatal care at Columbia University Irving Medical Center, an academic hospital system in Manhattan. Goals of implementation were to consolidate in-person prenatal screening, surveillance, and examinations into fewer in-person visits while maintaining patient access to ongoing antenatal care and subspecialty consultations via telehealth virtual visits. The rationale for this change was to minimize patient travel and thus risk for COVID-19 exposure. Because a large portion of obstetric patients had underlying medical or fetal conditions placing them at increased risk for adverse outcomes, prenatal care telehealth regimens were tailored for increased surveillance and/or counseling. Based on the incorporation of telehealth into prenatal care for high-risk patients, specific recommendations are made for the following conditions, clinical scenarios, and services: (1) hypertensive disorders of pregnancy including preeclampsia, gestational hypertension, and chronic hypertension; (2) pregestational and gestational diabetes mellitus; (3) maternal cardiovascular disease; (4) maternal neurologic conditions; (5) history of preterm birth and poor obstetrical history including prior stillbirth; (6) fetal conditions such as intrauterine growth restriction, congenital anomalies, and multiple gestations including monochorionic placentation; (7) genetic counseling; (8) mental health services; (9) obstetric anesthesia consultations; and (10) postpartum care. While telehealth virtual visits do not fully replace in-person encounters during prenatal care, they do offer a means of reducing potential patient and provider exposure to COVID-19 while providing consolidated in-person testing and services. KEY POINTS: · Telehealth for prenatal care is feasible.. · Telehealth may reduce coronavirus exposure during prenatal care.. · Telehealth should be tailored for high risk prenatal patients..

Telehealth Uptake into Prenatal Care and Provider Attitudes during the COVID-19 Pandemic in New York City: A Quantitative and Qualitative Analysis.

OBJECTIVE: This study aimed to (1) determine to what degree prenatal care was able to be transitioned to telehealth at prenatal practices associated with two affiliated hospitals in New York City during the novel coronavirus disease 2019 (COVID-19) pandemic and (2) describe providers' experience with this transition. STUDY DESIGN: Trends in whether prenatal care visits were conducted in-person or via telehealth were analyzed by week for a 5-week period from March 9 to April 12 at Columbia University Irving Medical Center (CUIMC)-affiliated prenatal practices in New York City during the COVID-19 pandemic. Visits were analyzed for maternal-fetal medicine (MFM) and general obstetrical faculty practices, as well as a clinic system serving patients with public insurance. The proportion of visits that were telehealth was analyzed by visit type by week. A survey and semistructured interviews of providers were conducted evaluating resources and obstacles in the uptake of telehealth. RESULTS: During the study period, there were 4,248 visits, of which approximately one-third were performed by telehealth (n = 1,352, 31.8%). By the fifth week, 56.1% of generalist visits, 61.5% of MFM visits, and 41.5% of clinic visits were performed via telehealth. A total of 36 providers completed the survey and 11 were interviewed. Accessing technology and performing visits, documentation, and follow-up using the telehealth electronic medical record were all viewed favorably by providers. In transitioning to telehealth, operational challenges were more significant for health clinics than for MFM and generalist faculty practices with patients receiving public insurance experiencing greater difficulties and barriers to care. Additional resources on the patient and operational level were required to optimize attendance at in-person and video visits for clinic patients. CONCLUSION: Telehealth was rapidly implemented in the setting of the COVID-19 pandemic and was viewed favorably by providers. Limited barriers to care were observed for practices serving patients with commercial insurance. However, to optimize access for patients with Medicaid, additional patient-level and operational supports were required. KEY POINTS: · Telehealth uptake differed based on insurance.. · Medicaid patients may require increased assistance for telehealth.. · Quick adoption of telehealth is feasible..

A contemporary amniotic fluid volume chart for the United States: The NICHD Fetal Growth Studies-Singletons.

BACKGROUND: Amniotic fluid is essential to normal fetal development and is estimated clinically with ultrasound scanning to identify pregnancies that are at risk for poor perinatal outcome. OBJECTIVE: Our goal was to develop a United States standard for amniotic fluid volume that is estimated by the amniotic fluid index and single deepest pocket. STUDY DESIGN: We performed a planned secondary analysis of a multicenter observational study of 2334 low-risk women with normal singleton gestations from 1 of 4 self-reported racial/ethnic groups. Eligible women had confirmed first-trimester dating criteria with health status, lifestyles, and medical and obstetric histories that were associated with normal fetal growth. Consenting women underwent serial (up to 5) sonographic evaluations of amniotic fluid between 15 and 40 weeks of gestation after being assigned randomly to 1 of 4 gestational age observation schedules. Twelve United States perinatal centers participated, and all sonograms were performed by credentialed sonographers who used identical, high-resolution equipment; caregivers were unaware of results but were notified for oligohydramnios. Women (n=597) who were subsequently found to have clinically significant antepartum complications were excluded. Racial/ethnic-specific nomograms for amniotic fluid index and single deepest pocket across gestation were developed with the use of linear mixed models with cubic splines; racial/ethnic differences were evaluated both with global and between-group tests. Median, 3rd, 5th, 10th, 90th, 95th and 97th percentile values were also estimated. We further considered the possible confounding effects of selected maternal characteristics and the estimated fetal weight at each sonogram. RESULTS: A total of 1719 pregnant women met inclusion criteria and had available data. These included 480 non-Hispanic white women, 418 non-Hispanic black women, 485 Hispanic women, and 336 Asian women. Both the amniotic fluid index and the single deepest pocket varied across gestation with maximal values at 26 and 33 weeks of gestation, respectively. Statistically significant differences were observed by maternal race/ethnicity. The between-group differences that were observed at 17-22 and 35-40 weeks of gestation remained statistically significant after adjustment for maternal characteristics and estimated fetal weight. These between-group racial/ethnic differences were most prominent after 35 weeks of gestation and at the extremes of dispersion (3rd and 97th percentiles). All 3rd and 97th percentile amniotic fluid index values were within the range of commonly used cutoffs to define oligohydramnios (≤5 cm) and polyhydramnios (≥25 cm). However, the 3rd percentile values ranged between 5.9 cm at 40 weeks of gestation and 10.1 cm at 25-27 weeks of gestation; the 97th percentile values ranged between 24.8 cm at 38 weeks of gestation and 15.7 cm at 15 weeks of gestation. CONCLUSION: Sonographic amniotic fluid volume estimates vary by racial/ethnic group, but the absolute differences appear to be small and may not be clinically significant. Selected maternal characteristics and estimated fetal weight did not affect the racial/ethnic differences. Between-group differences are maximal after 35 weeks of gestation and at the extremes of the upper and lower dispersion estimates. Given the observed variability in extreme (3rd and 97th percentile) dispersion values over the gestation, use of single cutoffs to define out-of-range measurements may not be appropriate clinically. These data might form a contemporary United States standard for amniotic fluid estimation that uses the amniotic fluid index and the single deepest pocket.

Term cesarean delivery in the first pregnancy is not associated with an increased risk for preterm delivery in the subsequent pregnancy.

BACKGROUND: Prior studies have reported an increased risk for preterm delivery following a term cesarean delivery. However, these studies did not adjust for high-risk conditions related to the first cesarean delivery and are known to recur. OBJECTIVE: The objective of the study was to determine whether there is an association between term cesarean delivery in the first pregnancy and subsequent spontaneous or indicated preterm delivery. STUDY DESIGN: This was a retrospective cohort study of women with the first 2 consecutive singleton deliveries (2007-2014) identified through a linked pregnancy database at a single institution. Women with a first pregnancy that resulted in cesarean delivery at term were compared with women whose first pregnancy resulted in a vaginal delivery at term. Exclusion criteria were known to recur medical or obstetrical complications during the first pregnancy. A propensity score analysis was performed by matching women who underwent a cesarean delivery with those who underwent a vaginal delivery in the first pregnancy. The association between cesarean delivery in the first pregnancy and preterm delivery in the second pregnancy in this matched set was examined using conditional logistic regression. The primary outcome was overall preterm delivery <37 weeks in the second pregnancy. Secondary outcomes included type of preterm delivery (spontaneous vs indicated), late preterm delivery (34-36 6/7 weeks), early preterm delivery (<34 weeks), and small-for-gestational-age birth. RESULTS: Of a total of 6456 linked pregnancies, 2284 deliveries were matched; 1142 were preceded by cesarean delivery and 1142 were preceded by vaginal delivery. The main indications for cesarean delivery in the first pregnancy were dystocia in 703 (61.5%), nonreassuring fetal status in 222 (19.4%), breech presentation in 100 (8.8%), and other in 84 (7.4%). The mean (SD) gestational ages at delivery for the second pregnancy was 38.8 (1.8) and 38.9 (1.7) weeks, respectively, for prior cesarean delivery and vaginal delivery. The risks of preterm delivery in the second pregnancy among women with a previous cesarean and vaginal delivery were 6.0% and 5.2%, respectively (adjusted odds ratio, 1.46, 95% confidence interval, [CI] 0.77-2.76). In an analysis stratified by the type of preterm delivery in the second pregnancy, no associations were seen between cesarean delivery in the first pregnancy and spontaneous preterm delivery (4.6% vs 3.9%; adjusted odds ratio, 1.40, 95% confidence interval, 0.59-3.32) or indicated preterm delivery (1.6% vs 1.4%; adjusted odds ratio, 1.21, 95% confidence interval, 0.60-2.46). Similarly, no significant differences were found in late preterm delivery (4.6% vs 4.1%; adjusted odds ratio, 1.13, 95% confidence interval, 0.55-2.29), early preterm delivery (1.6% vs 1.2%; adjusted odds ratio, 1.25, 95% confidence interval, 0.59-2.67), or neonates with birthweight less than the fifth percentile for gestational age (3.6% vs 2.2%; adjusted odds ratio, 1.26, 95% confidence interval, 0.52-3.06). CONCLUSION: After robust adjustment for confounders through a propensity score analysis related to the indication for the first cesarean delivery at term, cesarean delivery is not associated with an increase in preterm delivery, spontaneous or indicated, in the subsequent pregnancy.

Length of the second stage of labor and preterm delivery risk in the subsequent pregnancy.

BACKGROUND: Cervical injury is regarded as an important risk factor for preterm delivery. A prolonged second stage of labor may increase the risk of cervical injury that, in turn, may be associated with increased risk of spontaneous preterm delivery in the subsequent pregnancy. OBJECTIVE: We sought to evaluate whether the duration of the second stage of labor in a term primiparous singleton delivery is associated with an increased risk of singleton spontaneous preterm delivery (<37 weeks) in the second pregnancy. STUDY DESIGN: We carried out a retrospective cohort analysis of women with 2 consecutive pregnancies: a first term (≥37 weeks) delivery and second birth. Data were derived from a single institution's prospectively collected obstetrical database from January 2005 through January 2015. Duration of the second stage of labor was examined as a continuous variable, modeled based on nonparametric restricted cubic regression spline with 4 degrees of freedom. Second-stage duration was also examined as short (<30 minutes), normal (30-179 minutes), and prolonged, defined as ≥180 minutes. The association between the duration of the second stage of labor in the first term pregnancy and the risk for spontaneous preterm delivery in the second pregnancy was evaluated before and after adjusting for potential confounders based on the Cox proportional hazards regression model. Associations were expressed based on the adjusted hazard ratio and 95% confidence interval. RESULTS: In all, 6715 women met inclusion criteria. The hazard of spontaneous preterm delivery in the second pregnancy trended higher with both shorter and longer second-stage labors. The length of the second stage of labor in the first term delivery was categorized as short (<30 minutes) in 1749 (26.0%), normal (30-179 minutes) in 4551 (67.8%), and prolonged (≥180 minutes), in 415 (6.2%) women. Of these 6715 women with a first term delivery, 4.2% (n = 279) delivered spontaneously preterm in the second pregnancy. The risks of spontaneous preterm delivery among women with prolonged (≥180 minutes) second stage of labor and normal labor duration (30-179 minutes) were 5.4% (n = 22) and 3.5% (n = 158), respectively (adjusted hazard ratio, 1.81; 95% confidence interval, 1.15-2.84). This increased risk for prolonged second stage of labor was primarily seen among women who underwent a cesarean (hazard ratio, 3.38; 95% confidence interval, 1.09-10.49), but was imprecise among women who delivered vaginally (hazard ratio, 1.52; 95% confidence interval, 0.62-3.74). The risk of spontaneous preterm delivery among women with short second stage of labor (<30 minutes) in their first term pregnancy was 5.8% (n = 99; hazard ratio, 1.28; 95% confidence interval, 0.99-1.67). CONCLUSION: The risk of spontaneous preterm delivery in the second pregnancy was increased in women with a prolonged (≥180 minutes) second stage in the first term pregnancy. This risk was even greater among women who were delivered by cesarean in the first pregnancy.

Fetal growth velocity: the NICHD fetal growth studies.

BACKGROUND: Accurately identifying pregnancies with accelerated or diminished fetal growth is challenging and generally based on cross-sectional percentile estimates of fetal weight. Longitudinal growth velocity might improve identification of abnormally grown fetuses. OBJECTIVE: We sought to complement fetal size standards with fetal growth velocity, develop a model to compute fetal growth velocity percentiles for any given set of gestational week intervals, and determine association between fetal growth velocity and birthweight. STUDY DESIGN: This was a prospective cohort study with data collected at 12 US sites (2009 through 2013) from 1733 nonobese, low-risk pregnancies included in the singleton standard. Following a standardized sonogram at 10w0d-13w6d, each woman was randomized to 1 of 4 follow-up visit schedules with 5 additional study sonograms (targeted ranges: 16-22, 24-29, 30-33, 34-37, and 38-41 weeks). Study visits could occur ± 1 week from the targeted GA. Ultrasound biometric measurements included biparietal diameter, head circumference, abdominal circumference, and femur length, and estimated fetal weight was calculated. We used linear mixed models with cubic splines for the fixed effects and random effects to flexibly model ultrasound trajectories. We computed velocity percentiles in 2 ways: (1) difference between 2 consecutive weekly measurements (ie, weekly velocity), and (2) difference between any 2 ultrasounds at a clinically reasonable difference between 2 gestational ages (ie, velocity calculator). We compared correlation between fetal growth velocity percentiles and estimated fetal weight percentiles at 4-week intervals, with 32 (±1) weeks' gestation for illustration. Growth velocity was computed as estimated fetal growth rate (g/wk) between ultrasound at that gestational age and from prior visit [ie, for 28-32 weeks' gestational age: velocity = (estimated fetal weight 32-28)/(gestational age 32-28)]. We examined differences in birthweight by whether or not estimated fetal weight and estimated fetal weight velocity were <5th or ≥5th percentiles using χ2. RESULTS: Fetal growth velocity was nonmonotonic, with acceleration early in pregnancy, peaking at 13, 14, 15, and 16 weeks for biparietal diameter, head circumference, femur length, and abdominal circumference, respectively. Biparietal diameter, head circumference, and abdominal circumference had a second acceleration at 19-22, 19-21, and 27-31 weeks, respectively. Estimated fetal weight velocity peaked around 35 weeks. Fetal growth velocity varied slightly by race/ethnicity although comparisons reflected differences for parameters at various gestational ages. Estimated fetal weight velocity percentiles were not highly correlated with fetal size percentiles (Pearson r = 0.40-0.41, P < .001), suggesting that these measurements reflect different aspects of fetal growth and velocity may add additional information to a single measure of estimated fetal weight. At 32 (SD ± 1) weeks, if both estimated fetal weight velocity and size were <5th percentile, mean birthweight was 2550 g; however, even when size remained <5th percentile but velocity was ≥5th percentile, birthweight increased to 2867 g, reflecting the important contribution of higher growth velocities. For estimated fetal weight ≥5th percentile, but growth velocity <5th, birthweight was smaller (3208 vs 3357 g, respectively, P < .001). CONCLUSION: We provide fetal growth velocity data to complement our previous work on fetal growth size standards, and have developed a calculator to compute fetal growth velocity. Preliminary findings suggest that growth velocity adds additional information over knowing fetal size alone.

Characterization of Thermal and Mechanical Indices from Serial Ultrasound Exams and Associations with Neonatal Anthropometry: The NICHD Fetal Growth Studies.

OBJECTIVE: This article aims to determine if the number of maternal ultrasound scans where the highest thermal (TI) or mechanical (MI) indices recorded during obstetrical ultrasound exceed 1.0 were associated with neonatal anthropometric measurements. STUDY DESIGN: A prospective cohort of 2,334 nonobese low-risk pregnant women from 12 U.S. clinical sites underwent a total of six ultrasound scans, for which the highest TI and MI values were recorded. Neonatal anthropometric measurements were obtained within 12 to 24 hours of delivery. Multiple linear regression models adjusted for maternal race/ethnicity, body mass index, weight gain, and gestational age were used to examine associations between the number of maternal ultrasounds during gestation with a TI or MI exceeding 1.0 and the mean change in neonatal anthropometry. RESULTS: Ultrasounds with TI or MI >1.0 were not associated with birth weight, neonatal length, nor head, chest, and abdominal circumferences. TI >1.0 was negatively associated with neonatal mid-upper arm and mid-upper thigh circumferences. MI >1.0 was negatively associated with neonatal skinfold measurements of the anterior thigh and triceps, and neonatal circumferences of the mid-upper thigh and umbilicus. CONCLUSION: Prenatal ultrasound examinations in which TI or MI intermittently exceeded 1.0 did not identify a pattern of alterations of birth size.

Ultrasound Quality Assurance for Singletons in the National Institute of Child Health and Human Development Fetal Growth Studies.

OBJECTIVES: To report on the ultrasound quality assurance program for the National Institute of Child Health and Human Development Fetal Growth Studies and describe both its advantages and generalizability. METHODS: After training on an ultrasound system and software, research sonographers were expected to capture blank (unmeasured) images in triplicate for crown-rump length, biparietal diameter, head circumference, abdominal circumference, and femur length. A primary expert sonographer was designated and validated. A 5% sample (n = 740 of 14,785 scans) was randomly selected in 3 distinct rounds from within strata of maternal body mass index (round 1 only), gestational age, and research site. Unmeasured images were extracted from selected scans and measured with the ultrasound software by an expert sonographer. Correlations and coefficients of variation (CVs) were calculated, and the within-measurement standard deviation (ie, technical error of the measurement), was calculated. RESULTS: The reliability between the site sonographers and the expert was high, with correlations exceeding 0.99 for all dimensions in all rounds. The CV % values showed low variability, with the percentage differences being less than 2%, except for abdominal circumference in rounds 2 and 3, in which it averaged about 3%. Correlations remained high (>0.90) with increasing fetal size; there was a monotonic increase in technical errors of the measurement but without a corresponding increase in the CV %. CONCLUSIONS: Using rigorous procedures for training sonographers, coupled with quality assurance oversight, we determined that the measurements acquired longitudinally for singletons are both accurate and reliable for establishment of an ultrasound standard for fetal growth.

Do clinical practitioners seeking credentialing for nuchal translucency measurement demonstrate compliance with biosafety recommendations? Experience of the Nuchal Translucency Quality Review Program.

OBJECTIVES: The purpose of this study was to evaluate compliance with the ALARA (as low as reasonably achievable) principle by practitioners seeking credentialing for nuchal translucency (NT) measurement between 11 and 14 weeks' gestation. METHODS: Nuchal Translucency Quality Review Program credentialing requires quantitative scoring of 5 NT measurements from 5 different fetuses. Images submitted by 100 consecutive practitioners were retrospectively evaluated for the output display standard (ODS). The thermal index (TI) type (bone [TIb] or soft tissue [TIs]) and numeric value of the index were recorded. The TIb was considered the correct index for this study. Compliance with the numeric value was evaluated in several ways. Collectively, a TIb lower than 0.5 was considered optimal, lower than 0.7 compliant, and 1.0 or lower satisfactory. RESULTS: An ODS was present in at least 1 image submitted by 77 practitioners. The TIb was used exclusively by 15 (19.5%), the TIs by 37 (48.1%), and 25 used a combination of the TIb and TIs. Only 4 of 77 providers (5%) used the correct TI type (TIb) at lower than 0.5 for all submitted images, 5 of 77 (6%) at lower than 0.7, and 9 of 77 (12%) at 1.0 or lower. A TI (TIb or TIs) higher than 1.0 was used by 15 of 77 providers (19.5%). Proficiency in NT measurement and educational background (physician or sonographer) did not influence compliance with ALARA. CONCLUSIONS: Clinicians seeking credentialing in NT do not demonstrate compliance with the recommended use of the TIb in monitoring acoustic output.

Uterus and cervix anatomical changes and cervix stiffness evolution throughout pregnancy.

The coordinated biomechanical performance, such as uterine stretch and cervical barrier function, within maternal reproductive tissues facilitates healthy human pregnancy and birth. Quantifying normal biomechanical function and detecting potentially detrimental biomechanical dysfunction (e.g., cervical insufficiency, uterine overdistention, premature rupture of membranes) is difficult, largely due to minimal data on the shape and size of maternal anatomy and material properties of tissue across gestation. This study quantitates key structural features of human pregnancy to fill this knowledge gap and facilitate three-dimensional modeling for biomechanical pregnancy simulations to deeply explore pregnancy and childbirth. These measurements include the longitudinal assessment of uterine and cervical dimensions, fetal weight, and cervical stiffness in 47 low-risk pregnancies at four time points during gestation (late first, middle second, late second, and middle third trimesters). The uterine and cervical size were measured via 2-dimensional ultrasound, and cervical stiffness was measured via cervical aspiration. Trends in uterine and cervical measurements were assessed as time-course slopes across pregnancy and between gestational time points, accounting for specific participants. Patient-specific computational solid models of the uterus and cervix, generated from the ultrasonic measurements, were used to estimate deformed uterocervical volume. Results show that for this low-risk cohort, the uterus grows fastest in the inferior-superior direction from the late first to middle second trimester and fastest in the anterior-posterior and left-right direction between the middle and late second trimester. Contemporaneously, the cervix softens and shortens. It softens fastest from the late first to the middle second trimester and shortens fastest between the late second and middle third trimester. Alongside the fetal weight estimated from ultrasonic measurements, this work presents holistic maternal and fetal patient-specific biomechanical measurements across gestation.

The effect of intramuscular progesterone on the rate of cervical shortening.

OBJECTIVE: The purpose of the study was to evaluate whether 17-alpha-hydroxyprogesterone caproate (17-OHPC) exposure is associated with the rate of cervical shortening. STUDY DESIGN: Women with a history of spontaneous preterm delivery (PTD) at <37 weeks' gestation who had serial cervical length measurements (2009-2012) were identified. 17-OHPC administration and outcome data were collected. We excluded patients with multiple gestations, indicated PTDs, major fetal anomalies, cerclage, and vaginal progesterone use. The rate of cervical shortening was modeled in relation to 17-OHPC status with the use of methods for longitudinal data analysis. RESULTS: Two hundred thirty-seven patients with 1171 cervical length measurements were included, of whom 184 patients (77.6%) were exposed to 17-OHPC. Gestational age, number of previous PTDs, gestational age at initiation, and interval between cervical length examinations were similar between the 2 groups, although women who were not exposed to 17-OHPC were more likely to have delivered multiples in their previous PTD (24.5% vs 4.4%; P < .01). In the entire cohort, the rate of cervical shortening was identical, regardless of 17-OHPC exposure (0.85 mm per week). Among term deliveries, the rates of cervical shortening per week, on average, were 0.9 and 0.8 mm per week among women with and without 17-OHPC, respectively (P = .76). Among preterm deliveries, the corresponding rates were 0.8 and 1.2 mm, respectively, among women with and without 17-OHPC (P = .67). CONCLUSION: Cervical shortening among women with previous preterm delivery occurs at a similar rate, regardless of exposure to 17-OHPC.