Time Of First Trimester Screening Research Articles

Lower uterine segment scar assessment at 11-14 weeks' gestation to screen for placenta accreta spectrum in women with prior Cesarean delivery.

To validate prospectively transvaginal ultrasound assessment of the lower uterine segment (LUS) scar at the time of first-trimester screening in women with previous Cesarean section (CS) and to determine its feasibility and accuracy in stratifying women according to the risk for placenta accreta spectrum (PAS) disorder. Women with a history of CS were recruited between 11 + 0 and 13 + 6 weeks' gestation and underwent LUS scar assessment using transvaginal ultrasound. A standardized midsagittal plane, which included the cervicoisthmic canal (CIC), the uterine scar and the placental site, was obtained. The scar was described in terms of its size (narrow or dehiscent) and its location in relation to the CIC (within or above), with each LUS scar classified into one of four groups based on these features. Placental location was assessed and classified as high- or low-lying. Women were stratified according to the risk of PAS, based on the relationship between the scar location and placental site. Women were considered high risk when the scar was above the CIC and the placenta was low-lying (i.e. when the placenta was overlying an exposed scar) and low risk when the scar was within the CIC and/or the placenta was high. High-risk patients were followed up at 20 weeks and 28-30 weeks for the development of PAS. Maternal demographics, detailed obstetric history and obstetric outcome were collected. First-trimester transvaginal ultrasound was offered to 535 women with prior CS during the study period. A LUS scar was visualized in 79.9% (401/502) of those who agreed to undergo the examination. At this scan, the LUS scar was above the CIC in 9.0% (36/401) of women, but only 5.7% (23/401)additionally had a low-lying placenta overlying the scar. Of these 23 high-risk women, two were found to have PAS on the mid-trimester screening scan and one was noted to have placental adherence during evacuation following mid-trimester termination of pregnancy. On the first-trimester scan, 94.3% (378/401) of women were at low risk of PAS. This screening protocol yielded a positive likelihood ratio of 21.33 (95% CI, 13.02-34.96), sensitivity of 100% (95% CI, 29.24-100%), specificity of 95.31% (95% CI, 92.39-97.35%), positive predictive value of 16.7% (95% CI, 5.8-39.2%) and negative predictive value of 100% (95% CI, 98.4-100%). On multivariable regression analysis performed to identify confounding variables associated with a LUS scar above the CIC, only maternal body mass index ≥ 30 kg/m2 was significant (odds ratio (OR), 2.42 (95% CI, 1.04-5.39); P = 0.03). Although there was a trend towards an increased risk of a LUS scar above the CIC in women with prior elective prelabor CS (OR, 1.72 (95% CI, 0.80-3.68)), this association did not reach statistical significance. Routine transvaginal ultrasound assessment of the location of the LUS scar and placenta at the time of first-trimester screening between 11 + 0 and 13 + 6 weeks' gestation in women with prior CS is a feasible and effective tool to identify those at risk of subsequent development of PAS disorder. A finding of placental implantation over an exposed LUS scar seems to be cardinal in predicting the risk of PAS disorder in women with prior CS, with an excellent negative predictive value. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Frontonasal Malformation Diagnosis in the First Trimester: A Case Report

AbstractDifferent components of the face and the brain develop independently and ultimately unite at the midline. Disruptions in the development and fusion of craniofacial midline give rise to myriad of abnormalities broadly classified as frontonasal malformations. Here, we report a case diagnosed in the first trimester. The fetus had midline cleft of the face extending till forehead, cleft lip and palate, absent nasal tip and arhinia. There was associated alobar holoprosencephaly and polydactyly in all the four limbs. This case illustrates the importance of evaluation of facial profile, retronasal triangle and 3 D scanning at the time of first trimester screening.

Nearly half of all severe fetal anomalies can be detected by first-trimester screening in experts' hands.

Objective To evaluate the detection rate of severe fetal anomalies at the first-trimester screening (FTS) and, vice versa, to evaluate the follow-up of pathological results at FTS at the time of mid-trimester screening (MTS) and throughout pregnancy and delivery in a partially selected population of low-risk pregnancies. Methods We conducted a prospective study on the detection of severe fetal anomalies at routine FTS in 9891 pregnant women with 10,294 fetuses between 11 + 0 and 13 + 6 weeks of gestation. The findings of FTS were compared to the results of MTS and pregnancy and neonatal outcomes. Only cases with severe fetal anomalies were taken for statistical analysis in this study. Results There were 232 cases of fetal anomaly altogether. At the time of FTS, sonographic anomalies were diagnosed in 113 cases and further ultrasound controls arranged. In four cases, fetal anomaly was not confirmed by MTS; in the remaining 109 cases, the sonographic anomaly seen at FTS was confirmed at MTS and in the course of pregnancy with a resulting sensitivity for fetal malformation at FTS of 47.8%, a specificity of 99.96%, a positive predictive value of 96.5% and a negative predictive value of 98.8%. Conclusion FTS can detect almost half of all severe fetal anomalies at an early stage of pregnancy with positive predictive values of 90% and more. Sensitivities varied depending on the organ system and reached the highest figures for anomalies of the heart, the abdomen, the spine and the skeletal system.

Combination of serum histidine-rich glycoprotein and uterine artery Doppler to predict preeclampsia.

The primary aim of this study is to determine the value of using a combination of serum histidine-rich glycoprotein (HRG) level and uterine artery pulsatility index (PI) in pregnant women at 11-13+6 weeks' gestation to predict preeclampsia. The secondary aim is to determine the association between other pregnancy complications with the use of these combined tests. Transabdominal uterine artery PI and serum HRG level were measured at the time of first-trimester aneuploidy screening at 11-13+6 weeks' gestation in 327 pregnant women. The primary outcome was preeclampsia. The predictive values of this combination test were calculated. Eighteen cases developed preeclampsia (5.5%) and four of these preeclamptic cases were early-onset preeclampsia (1.2%). The sensitivity, specificity, positive predictive value, and negative predictive value of uterine artery PI combined with serum HRG level to predict preeclampsia were 11.1%, 96.8%, 16.7%, and 94.9%, respectively. For the prediction of early-onset preeclampsia, the sensitivity, specificity, positive predictive value, and negative predictive value were 25%, 97.1%, 10%, and 99%, respectively. An abnormal uterine artery PI and abnormal serum HRG level were associated with preterm delivery and intrauterine growth restriction. Our findings reveal that the combination of uterine artery PI and serum HRG level at 11-13+6 weeks of gestation is not an effective method for predicting preeclampsia at the time of first-trimester screening.

441: Applicability of standardized fetal heart examination in obese population at first trimester

Evaluate the influence of maternal obesity on demonstration of standard fetal cardiac landmarks at first trimester screening This is a secondary analysis of a prospective study of serial cardiac exams in high-risk fetuses. At the time of first trimester screening (Nuchal translucency, nasal bone, anatomy, Doppler, and serum testing) we added standardized fetal heart exam using 2D ultrasound with power Doppler, following the ALARA principle. Standardized protocol: 4-chamber view (4ChV), outflow tract relationship (OTR), transverse arches view (TAV). (Figure 1) Obesity was stratified by Body Mass Index: group 1 <30, group 2 30-40, group 3 40-50, group 4 >50. Successful visualization of cardiac landmarks (4ChV, OTR, TAV), route of study (transabdominal v transvaginal (TV)) and length of the combined exam (duration) were compared between obese and non-obese women. Findings were confirmed by second trimester and/or postnatal echocardiography. Categorical values were compared using Fisher’s exact test. Subgroup analysis was performed using linear-by-linear association We performed 154 fetal heart exams. Median crown rump length was 67.6mm (45.4-90.5). About half the mothers were obese (49%, n=76). The standardized protocol successfully identified 4ChV in all fetuses. OTR and TAV were shown in 99% and 97% in non-obese and obese women respectively (p>0.05 for all). TV exam was required more often in obese women (10/76 v 1/78 non-obese, p<0.01). Exam duration was increased in obese women (34min v 40min, p=0.01). Visualization of the landmarks was not different in obesity subgroup analysis (p>0.05 for all). Conversion to TV route increased with increasing BMI category (1.3%, 9.3%, 16% and 25% in groups 1 to 4 respectively, p=0.01). There was a trend to step-wise increase in total duration from Group 1 to 4 (34, 39, 40 and 45 minutes, respectively p=0.06). All serious cardiac defects were correctly diagnosed in both groups, although the numbers do not allow formal analysis (3 in non-obese, one hypoplastic L heart in the obese group.) Obesity does not hamper visualization of cardiac anatomical landmarks in the first trimester when this standardized method is used. Obesity may require more transvaginal exams without significantly prolonging the scanning time. Obese women should not be excluded from first trimester cardiac assessment.

EP10.01: Asymmetry of the lateral ventricles and choroid plexus at the time of first trimester screening as a possible early sign of hemimegalencephaly

EP10.01: Asymmetry of the lateral ventricles and choroid plexus at the time of first trimester screening as a possible early sign of hemimegalencephaly

OP17.02: 2D Estimated Placental Volume (EPV) measurements in first trimester are reliable and correlate with measurements obtained by the 3D VOCAL™ technique

A 3D volume of the placenta was acquired at the time offirst trimester screening for aneuploidy (11 w0d-14w0d). Offlineevaluation of the volumes was performed independently by 2experienced operators (MR & JG) for EPV from a selected 2Dplane and for 3D volume using VOCAL. Intraclass correlation(ICC) was used to assess inter- and intraobserver variability forEPV. Correlation of mean placental volumes calculated by the EPVmethod to the volume obtained using VOCAL was also assessed.

The role of ultrasound and antenatal single-shot fast spin-echo MRI in the evaluation of herniated bowel in case of first trimester ultrasound diagnosis of fetal gastroschisis

To report on a clinical antenatal management strategy based on integrating ultrasound (US) and magnetic resonance imaging (MRI) in the evaluation of herniated bowel following early prenatal diagnosis of gastroschisis. Antenatal US and ultrafast single-shot spin-echo (SSSE) MRI. Fetal gastroschisis was documented at 12 weeks at the time of first trimester screening for Down syndrome. Fetal karyotype was performed at 16 weeks and showed a 46,XY karyotype. Ultrasound scan at 20 weeks diagnosed gastroschisis as isolated finding. Follow-up scans were planned monthly, and antenatal ultrafast SSSE MRI was arranged at 35 weeks and demonstrated a right fetal abdominal wall defect measuring 2.4 mm on transverse diameter with an integrity of the intra-abdominal and extra-abdominal loops of small bowel. The colon was in situ as were the stomach, the liver, and the spleen. The choice of integrating both the diagnostic procedures has shown to be clinically useful in planning the timing of delivery (Cesarean section) and in turn has been associated with an easy surgical repair and to a favorable postnatal outcome. The result of amniocentesis was crucial for the parent's decision-making process whether to continuing with the pregnancy. Moreover, amniotic fluid α-fetoprotein levels may be used as an index of small bowel damage when loops of small bowel lied uncovered within the amniotic cavity.

The Utility of Genetic Counseling Prior to Offering First Trimester Screening Options

In order to evaluate the utility of genetic counseling at the time of first trimester screening in patients with no previously identified genetic concerns, we reviewed family history data for 700 women seen for genetic counseling in Utah during 2005-2006. The mean maternal age was 35 years (Range: 16-47 years). The majority of patients seen were non-Jewish Caucasians (90.8%, 634/700). A three-generation pedigree was obtained from each woman by one of two certified genetic counselors and subsequently classified as "negative" (no birth defects/genetic disorders); "positive" (birth defect or genetic condition with a minimal/low risk of recurrence; additional evaluation/genetic testing during pregnancy not indicated); or "significant" (birth defect or genetic condition with an increased risk of recurrence; additional evaluation/genetic testing during the pregnancy indicated). About 72% (501/700) of the histories were negative, 19% (134/700) were positive, and about 9% (65/700) were significant. Among patients with significant family histories, 66% (n = 43) were women less than 35 years of age. We conclude that assessing a patient's family history at the time of first trimester serum screening is a valuable resource for pregnancy management.

Performing a Fetal Anatomy Scan at the Time of First-Trimester Screening

Over the past decade, prenatal diagnosis has shifted rapidly from the second trimester into the first trimester. Although the nuchal-translucency scan may detect a small proportion of fetal structural malformations, fetal anatomy is not routinely assessed until the fetal anatomical survey is performed in the second trimester between 18 and 22 weeks. The recent development of high-frequency transvaginal ultrasound transducers has led to vastly improved ultrasound resolution and improved visualization of fetal anatomy earlier in gestation. Several pilot studies of a first-trimester anatomic survey have reported detection rates comparable with those achieved in the routine second-trimester anatomic survey. As advanced ultrasound technology becomes more available, there is an urgent need to evaluate the diagnostic ability of a first-trimester anatomic survey and to determine the role of a first-trimester anatomic survey in the current screening paradigm.

Detection of Twin Reversed Arterial Perfusion Sequence at the Time of First-Trimester Screening

Twin reversed arterial perfusion (TRAP) sequence, also known as acardiac malformation, is a rare complication unique to monozygotic multiple gestations. It occurs in approximately 1 per 35,000 pregnancies and in 0.3% of all monozygotic twin gestations. The malformation is characterized by the lack of a well-defined cardiac structure in one twin (acardiac), which acts as a parasite that is hemodynamically dependent on the normal (pump) twin. The malformation in the acardiac twin is always incompatible with survival regardless of its extent, whereas the prognosis of the pump twin may vary considerably. Common complications that affect the prognosis of the pump twin include complications of prematurity secondary to preterm delivery and polyhydramnios as well as congestive heart failure due to the expended cardiac demand. Without prompt detection, follow-up, and treatment, mortality rates for pump twins have been noted to be as high as 50% to 70%. Early sonographic diagnosis, appropriate follow-up, and intervention via cord occlusion when indicated are the mainstays of prenatal care in cases of TRAP sequence and have been associated with substantial improvements in survival. We report a case that emphasizes the added value of 3-dimensional (3D) and color Doppler techniques for both diagnosis of TRAP sequence and detection of poor prognostic features in the first or early second trimester.

Fetal gender screening by ultrasound at 11 to 13+6 weeks

To survey the accuracy of fetal gender determination during first trimester screening and scan for congenital anomalies. A prospective observational study was performed on 496 singleton pregnancies at the first trimester ultrasound screening. The doctor was a certified sonographer of first trimester screening by the Fetal Medicine Foundation(FMF). Ultrasound examination was performed on a GE Voluson 730 Pro, transabdominally, between 11 and 13(+6) weeks. Both transverse and mid-sagittal planes of a section of the fetal genital tubercle were performed to identify the gender. The subsequent gender at birth was obtained from karyotyping reports or hospital birth records. During the study, 496 patients requested gender information at the time of first trimester screening. Of the patients it was possible to determine gender (441 out of 496), the scan achieved an overall success rate of 91.8% in correctly identifying gender. The success rate for correctly identifying fetal gender (where identification was possible) increased with gestational age, from 71.9% at 11 weeks, 92% at 12 weeks, and 98.3% at 13 weeks, respectively, where gestational age was calculated from the crown-rump length in conjunction with menstrual or ovulation dating (p<0.001). Of the 55 cases where no identification of gender was possible, 39 were in the 11-week gestational age group, representing 40.6% of this category. The overall fetal gender accuracy rate for male fetus was slightly better than female (92.5 versus 91.2%), but was not statistically significant. This study demonstrated that the gestational age of the fetus has a material effect on the accuracy rate of gender determination. At 12 weeks and over, the average success rate for correctly identifying gender, where gender identification was possible, was 94.8%, with the accuracy at 13 weeks of 98.3% approaching that achieved by invasive testing. Fetal gender identification at 11

P01.45: Fetal gender screening by ultrasound at 11–13+6 weeks

To survey the accuracy of fetal gender determination during the first-trimester screening and scan for congenital anomalies. A prospective observational study was performed on 496 singleton pregnancies at the first-trimester ultrasound screening. The doctor was certified by The Fetal Medicine Foundation (FMF). Ultrasound examination was performed on a GE Voluson 730 Pro transabdominally between 11–13 + 6 weeks. Both transverse and mid-sagittal planes of section of the fetal genital tubercle were done to identify the gender. The subsequent gender at birth was obtained from the karyotyping reports or the hospital birth records. During the study 496 patients requested gender information at the time of first-trimester screening. Of those patients where it was possible to determine gender (441 out of 496) the scan achieved an overall success rate of 92.3% in correctly identifying gender. It was found that both transverse and mid-sagittal planes to identify fetal gender were necessary to improve determination. When the crown-rump length was 45.0–56.0 mm, the accuracy rate was 75.4%, when the crown-rump length was 57.0–67.0 mm, the accuracy rate was 92.0% (P < 0.001), when the crown-rump length was 68.0–84.0 mm, the accuracy rate was rose to 98.3% (P < 0.001). The fetal gender accuracy rate for male fetus was slightly better than female (93.4% vs 91.2%) but is not statistically significant. This study demonstrated that the 11–13 + 6 weeks scan achieved an overall adjusted accuracy of 82.1% in correctly determining fetus gender. The gestation age of the fetus had a material effect on the accuracy rate of gender determination.

Prenatal Sonographic Findings in Trisomy 22

The purpose of this study was to survey prenatal sonographic findings and their frequencies in fetuses with complete trisomy 22 and to identify potential sonographic markers of this aneuploidy. Sonographic examinations of 5 fetuses were performed and chromosome analysis was conducted after amniocentesis, chorionic villus sampling, cordocentesis, or a combination thereof. The sonographic findings were compared with other prenatal cases in the literature. Intrauterine growth restriction, hypoplastic femurs, nuchal thickening, cerebellar defects, and oligohydramnios were the most frequently observed anomalies in all considered cases of late first-, second-, and third-trimester scans. These anomalies represent commonly accepted sonographic markers for chromosomal defects in general, some recognizable from the time of first-trimester screening (12th-14th weeks of gestation) and stress their importance for prenatal sonographic scans.