The prognostic role of CRL discordance in first trimester ultrasound.

OBJECTIVES: In the first trimester, intertwin crown-rump length (CRL) discordance has emerged as a notable factor linked to adverse perinatal health effects. It is frequently employed as a basis for counseling parents regarding potential adverse pregnancy outcomes. Despite its established association with adverse outcomes, the significance of CRL discordance in substantially predicting pregnancy problems and its efficacy in pregnancy screening remain subjects of ongoing discussion. The aim of this manuscript is to present current knowledge on CRL discordance. METHODS: PubMed was searched for related articles with terms "Crown-Rump length", "Prenatal Screening", "Twin pregnancy", "Discordance". RESULTS: Twenty-two studies were included in our study with six reporting data on monochorionic and 16 assessing the correlation between CRL discordance and adverse pregnancy outcomes. Fetal loss at the 20th and 24th week of the pregnancy, SGA neonates, pre-term delivery (32 weeks), perinatal death (24 weeks) are all reported adverse outcomes associated with CRL discordance. The reported cut-off for increased risk of adverse perinatal outcomes is a discordance of at least 10% or more. CONCLUSIONS: Increased CRL (>10 %) discordance is linked to a higher risk of sFGR in both monochorionic and dichorionic pregnancies, fetal loss, and preterm delivery.

Postconceptual Neonatal Dating by Transmastoid Ultrasound of Transcerebellar Diameter-Comparison to Crown Rump Length Measurement: A Proof of Concept Paper.

OBJECTIVES: Transcerebellar diameter (TCD) has been utilized prenatally as a tool to estimate gestational age (GA) when fetal growth aberrations are suspected. Traditionally, first trimester ultrasound (1TUS) has been the gold standard of dating a pregnancy in spontaneous pregnancies. We sought to determine if neonatal TCD measurement was as accurate as 1TUS in the estimation of postconceptual gestational age (PCGA). METHODS: A retrospective cohort from a registry of high-quality transmastoid views of consecutive patients from July 2019 to November 2020, delivered from 24 to 34 weeks GA, and with a 1TUS were included. The reference PCGA was the sum of the GA at delivery by 1TUS and day of life. The PCGA by TCD was calculated from Chang et al for GA by TCD. Reference and experimental values were compared by correlation, agreement within 7 days, and Bland-Altman analysis. RESULTS: Of the 154 individual patients in the registry of high-quality transmastoid views during the study period, 62 met inclusion and exclusion criteria. PCGA by 1TUS and TCD were highly correlated (r = 0.86, P < .001; κ = 47% agreement within 7 days of PCGA). The bias of PCGA by TCD was 4.6 days earlier than the PCGA by 1TUS (95% confidence interval of agreement: -29.2, 20). CONCLUSIONS: PCGA estimation by neonatal transmastoid TCD was highly correlated with that of 1TUS. It generally underestimates GA by 4.6 days. This relationship warrants further investigation to determine if this method of estimating PCGA in undated gestations is generalizable.

Clinical implications of crown-rump length discordance at 11 to 14 weeks in dichorionic twins.

BACKGROUND: Crown-rump length discordance, defined as ≥10% discordance, has been investigated as an early sonographic marker of subsequent growth abnormalities and is associated with an increased risk of fetal loss in twin pregnancies. Previous studies have not investigated the prevalence of fetal aneuploidy or structural anomalies in twins with discordance or the independent association of crown-rump length discordance with adverse perinatal outcomes. Moreover, data are limited on cell-free DNA screening for aneuploidy in dichorionic twins with discordance. OBJECTIVE: This study aimed to evaluate whether crown-rump length discordance in dichorionic twins between 11 and 14 weeks of gestation is associated with a higher risk of aneuploidy, structural anomalies, or adverse perinatal outcomes and to assess the performance of cell-free DNA screening in dichorionic twin pregnancies with crown-rump length discordance. STUDY DESIGN: This was a secondary analysis of a multicenter retrospective cohort study that evaluated the performance of cell-free DNA screening for the common trisomies in twin pregnancies from December 2011 to February 2020. For this secondary analysis, we included live dichorionic pregnancies with crown-rump length measurements between 11 and 14 weeks of gestation. First, we compared twin pregnancies with discordant crown-rump lengths with twin pregnancies with concordant crown-rump lengths and analyzed the prevalence of aneuploidy and fetal structural anomalies in either twin. Second, we compared the prevalence of a composite adverse perinatal outcome, which included preterm birth at <34 weeks of gestation, hypertensive disorders of pregnancy, stillbirth or miscarriage, small-for-gestational-age birthweight, and birthweight discordance. Moreover, we assessed the performance of cell-free DNA screening in pregnancies with and without crown-rump length discordance. Outcomes were compared with multivariable regression to adjust for confounders. RESULTS: Of 987 dichorionic twins, 142 (14%) had crown-rump length discordance. The prevalence of aneuploidy was higher in twins with crown-rump length discordance than in twins with concordance (9.9% vs 3.9%, respectively; adjusted relative risk, 2.7; 95% confidence interval, 1.4-4.9). Similarly, structural anomalies (adjusted relative risk, 2.5; 95% confidence interval, 1.4-4.4]) and composite adverse perinatal outcomes (adjusted relative risk, 1.2; 95% confidence interval, 1.04-1.3) were significantly higher in twins with discordance. A stratified analysis demonstrated that even without other ultrasound markers, there were increased risks of aneuploidy (adjusted relative risk, 3.5; 95% confidence interval, 1.5-8.4) and structural anomalies (adjusted relative risk, 2.7; 95% confidence interval, 1.5-4.8) in twins with CRL discordance. Cell-free DNA screening had high negative predictive values for trisomy 21, trisomy 18, and trisomy 13, regardless of crown-rump length discordance, with 1 false-negative for trisomy 21 in a twin pregnancy with discordance. CONCLUSION: Crown-rump length discordance in dichorionic twins is associated with an increased risk of aneuploidy, structural anomalies, and adverse perinatal outcomes, even without other sonographic abnormalities. Cell-free DNA screening demonstrated high sensitivity and negative predictive values irrespective of crown-rump length discordance; however, 1 false-negative result illustrated that there is a role for diagnostic testing. These data may prove useful in identifying twin pregnancies that may benefit from increased screening and surveillance and are not ascertained by other early sonographic markers.

High sensitivity and specificity in fetal gender identification in the first trimester, using ultrasound and Noninvasive Prenatal Screening (NIPS) in twin pregnancies, a prospective study.

INTRODUCTION: Determination of the fetal gender in the first trimester is important in twin pregnancy cases of familial X-linked genetic syndromes and helps determine chorionicity. We assessed and compared the accuracy of first-trimester ultrasound scans, and cell-free fetal DNA (CfDNA) in determining fetal gender in the first trimester of twin pregnancies. METHODS: Women with twin pregnancies were recruited prospectively during the first trimester. Fetal gender was determined using both ultrasound scans and CfDNA screening. Both results were compared to the newborn gender after delivery. RESULTS: A total of 113 women with twin pregnancies were enrolled. There was 100% sensitivity and specificity in Y chromosome detection using CfDNA. Gender assignment using ultrasound in any first-trimester scans was 79.7%. Accuracy level increased from 54.2% in CRL 45-54 mm to 87.7% in CRL 55-67 mm and 91.5% in CRL 67-87 mm. Male fetuses had significantly higher chances of a gender assignment error compared to female fetuses, odds ratio = 23.574 (CI 7.346 - 75.656). CONCLUSIONS: CfDNA is highly sensitive and specific in determining the presence of the Y chromosome in twin pregnancies in the first trimester. Between CRL 55-87 mm, ultrasound scanning offers a highly accurate determination of fetal gender in twin pregnancies.

Validation of Ultrasound Dating Protocols Using Data From Twins Conceived Through In Vitro Fertilization in Nova Scotia: A Retrospective Cohort Study.

OBJECTIVES: Clinical practice guidelines recommend determining gestational age (GA) for twin pregnancies using the fetal crown rump length (CRL) of the larger fetus. This study investigated whether the CRL of the larger or smaller fetus at 11-14 weeks best predicted in vitro fertilization (IVF) assigned GA. METHODS: A retrospective cohort study of twin pregnancies conceived by IVF ± intracytoplasmic sperm injection, 2004-2022, generated GA estimations for each co-twin CRL at the 11-14 week ultrasound, to determine which fetus (smaller or larger) more consistently predicted IVF-assigned GA. Monoamniotic twins and twins with known structural or vascular abnormalities were excluded. Paired t tests evaluated the ability of CRL to predict GA, and logistic regression evaluated the predictive ability of each of the co-twin groups with increasing size differences. Statistical significance was set at P < 0.05. RESULTS: Viewpoint 6 identified 359 eligible twin pairs. CRL was closest with the smaller fetus (0.38 days); CRL for both the smaller (95% CI 0.16-0.61) and the larger (2.25 days, 95% CI 2.04-2.46) fetus showed deviation from IVF-assigned GA. As the absolute difference between the small and large fetus increased, the ultrasound-estimated GA of the smaller fetus was still consistently closer to IVF-assigned GA. CONCLUSIONS: In this selected population of twins with known GA, the CRL of the smaller fetus more accurately predicted IVF-assigned GA even with increasing differences in fetal size. These findings provide important information for appropriately dating pregnancies to facilitate adherence to national guidelines to monitor for pregnancy complications, and plan frequency and type of fetal surveillance, as well as timing of delivery.

Three-dimensional morphological analysis of the human spleen and its surrounding organs during the early fetal period.

The spleen has variations in its morphology and is considered to acquire a defined shape in the third month of gestation. However, few studies have investigated spleen development during the first 3 months of fetal life. This study aimed to determine the three-dimensional (3D) morphogenesis of the spleen during the third month of gestation. In this study, 30 fetal specimens (crown-rump length [CRL]: 22-103 mm) were subjected to magnetic resonance imaging analysis. We manually segmented the spleen, stomach, and adrenal gland, reconstructed 3D models, and analyzed the volume and shape of these organs. The results showed that the variation in spleen size was large compared to that in other organs. Spleen morphology was classified into six types based on the number of splenic surfaces as follows: two-faced, three-faced, four-faced, five-faced, ovoid, and irregular. Two-faced spleens were only observed in small specimens, whereas three- and four-faced spleens were observed in larger specimens. We also revealed that the number of fetal splenic surfaces increased as CRL enlarged. Additionally, 3D models indicated that some specimens formed their splenic surfaces without contact with the adjacent organs. This suggested that the splenic surface may be caused not only by pressure from the faced organs but also by an intrinsic program. This study may provide a better understanding of the normal development of the spleen during the early fetal period, and may potentially assist future studies in investigating congenital morphological anomalies of the spleen.

Embryonic and fetal tiny pericardial fluid collections at less than 12 weeks of gestation.

OBJECTIVES: To describe embryonic and fetal tiny pericardial fluid collections (PFCs) using transvaginal sonography and HDlive Silhouette at less than 12 weeks of gestation. METHODS: During an 8-month period from November 2021 to June 2022, one-hundred and thirty transvaginal scans were performed for first-trimester dating, and eleven tiny PFCs of the embryo or fetus were identified at 8+4 - 11+3 weeks of gestation (three at 8, six at 9, and two at 11 weeks). HDlive Silhouette features of PFC were evaluated. Their clinical characteristics and outcomes were also investigated. RESULTS: The incidence of tiny PFCs was 8.5 % at less than 12 weeks of gestation. The mean gestational age at the initial examination was 9.5 weeks (SD: ± 0.9). The mean crown-rump length was 25.0 mm (SD: ± 8.5). The mean PFC dimension was 0.8 mm (range: 0.5-1.3, SD: ± 0.2). Pleural effusion was associated with 3 out of 11 PFCs (27.2 %). Ascites was noted in 2 cases (18.2 %). Skin edema was identified in only in 1 case (0.09 %). There was no arrhythmia. Tiny PFC could also be depicted using HDlive Silhouette. First-trimester fetal ultrasound scans at 11 - 13+6 weeks showed no abnormal findings. PFCs resolved until 13 weeks of gestation (Mean: 12 weeks, SD: ± 1.2). All PFC pregnancies resulted in healthy neonates. CONCLUSIONS: The incidence of tiny PFCs was relatively high in early pregnancy. HDlive Silhouette can depict tiny PFCs of the embryo. Tiny PFCs in early gestation are transient, benign findings in utero.

Combining early pregnancy bleeding with ultrasound measurements to assess spontaneous abortion risk among infertile patients.

BACKGROUND: Approximately 15% of all clinically recognized pregnancies in patients with infertility result in spontaneous abortion. However, despite its potential to have a profound and lasting effect on physical and emotional well-being, the natural history of spontaneous abortion in women with infertility has not been described. Although vaginal bleeding is a common symptom in pregnancies conceived via reproductive technologies, its prognostic value is not well understood. OBJECTIVE: This study aimed to evaluate the combination of early pregnancy bleeding and first-trimester ultrasound measurements to determine spontaneous abortion risk. STUDY DESIGN: This was a retrospective cohort study of patients with infertility who underwent autologous embryo transfer resulting in singleton intrauterine pregnancy confirmed by ultrasound from January 1, 2017, to December 31, 2019. Early pregnancy symptoms of bleeding occurring before gestational week 8 and measurements of crown-rump length and fetal heart rate from ultrasounds performed during gestational week 6 (6 0/7 to 6 6/7 weeks of gestation) and gestational week 7 (7 0/7 to 7 6/7 weeks of gestation) were recorded. Modified Poisson regression with robust error variance was adjusted a priori for patient age, embryo transfer day, and transfer of a preimplantation genetic-tested embryo to estimate the relative risk and 95% confidence interval of spontaneous abortion for dichotomous variables. The relative risks and positive predictive values for early pregnancy bleeding combined with ultrasound measurements on the occurrence of spontaneous abortion were calculated for patients who had an ultrasound performed during gestational week 6 and separately for patients who had an ultrasound performed during gestational week 7. The primary outcome was spontaneous abortion in the setting of vaginal bleeding with normal ultrasound parameters. The secondary outcomes were spontaneous abortion with vaginal bleeding and (1) abnormal crown-rump length, (2) abnormal fetal heart rate, and (3) both abnormal crown-rump length and abnormal fetal heart rate. RESULTS: Of the 1858 patients who were included (359 cases resulted in abortions and 1499 resulted in live births), 315 patients (17.0%) reported vaginal bleeding. When combined with ultrasound measurements from gestational week 6, bleeding was significantly associated with increased spontaneous abortion only when accompanied by absent fetal heart rate (relative risk, 5.36; 95% confidence interval, 3.36-8.55) or both absent fetal heart rate and absent fetal pole (relative risk, 9.67; 95% confidence interval, 7.45-12.56). Similarly, when combined with ultrasound measurements from gestational week 7, bleeding was significantly associated with increased spontaneous abortion only when accompanied by an abnormal assessment of fetal heart rate or crown-rump length (relative risk, 5.09; 95% confidence interval, 1.83-14.19) or both fetal heart rate and crown-rump length (relative risk, 14.82; 95% confidence interval, 10.54-20.83). With normal ultrasound measurements, bleeding was not associated with increased spontaneous abortion risk (relative risk: 1.05 [95% confidence interval, 0.61-1.78] in gestational week 6 and 0.80 [95% confidence interval, 0.36-1.74] in gestational week 7), and the live birth rate was comparable with that in patients with normal ultrasound measurements and no bleeding. CONCLUSION: Patients with a history of infertility who present after embryo transfer with symptoms of vaginal bleeding should be evaluated with a pregnancy ultrasound to accurately assess spontaneous abortion risk. In the setting of normal ultrasound measurements, patients can be reassured that their risk of spontaneous abortion is not increased and that their live birth rate is not decreased.

A new formula for estimating gestational age by crown-rump length.

BACKGROUND: The accurate estimation of gestational age by ultrasound is crucial in prenatal care for the monitoring of fetal growth and development. As changes in maternal childbearing age, body habitus, and ultrasound technology occur, previously published formulas may not be accurate for today's population. OBJECTIVE: This study aimed to develop new formulas for calculating the gestational age based on a first-trimester ultrasound scan and to compare the new formulas with preexisting formulas. STUDY DESIGN: This study was a single-center, retrospective observational study that included pregnancies conceived using in vitro fertilization. The pregnancies had known dates of embryo transfer and multiple standard ultrasound examinations in the first trimester of pregnancy. Pregnancies ending with a miscarriage or termination in the first trimester of pregnancy were excluded. A polynomial regression analysis was performed to determine the optimal model that represented the relationship between gestational age and crown-rump length. The models were evaluated using systematic error, random error, absolute difference of the calculated gestational age and actual gestational age, and proportion of estimation within 0 and 2 days of the known gestational age. The optimal model was chosen and compared with preexisting formulas. RESULTS: Overall, 1436 ultrasound results were included in the analysis. The analysis produced 3 models: linear, cubic, and quadratic models with correlation coefficients of 0.968, 0.989, and 0.991, respectively. The cubic formula was superior to the linear and quadratic formulas concerning systematic error, random error, absolute difference, and proportion of estimation within 0 and 2 days. The new formula had a lower systematic error, random error, and mean absolute difference (0.06%, 2.43%, and 0.97 days, respectively) and the highest proportion of estimation within 0 and 2 days (37.4% and 93.5%, respectively) than previously published formulas. CONCLUSION: The formula proposed in this study followed a cubic model and seemed to be able to more accurately estimate gestational age in the first trimester of pregnancy based on crown-rump length compared with previously published formulas.

Is bigger better? A comparison of growth restriction rates using the crown-rump length derived due date from the smaller versus larger twin.

BACKGROUND: Although the smaller twin's crown-rump length is most accurate in establishing the estimated due date in dichorionic gestations, societal guidelines favor the use of the larger twin measurements based on concern for missing a diagnosis of fetal growth restriction. OBJECTIVE: This study aimed to compare the accuracy of the diagnosis of early- and late-onset fetal growth restriction in dichorionic twin gestations conceived by assisted reproductive technology using the estimated due date as established by the crown-rump length of the smaller vs larger twin. STUDY DESIGN: This was a 10-year retrospective cohort study of nonanomalous, dichorionic gestations conceived with assisted reproductive technology at 2 institutions. The incidence of early-onset (<32 weeks of gestation) and late-onset (≥32 weeks of gestation) growth restriction derived from the Hadlock formula using the smaller and larger crown-rump length estimated due date was compared with the true estimated due date by assisted reproductive technology. Statistical significance was determined using the Fisher exact test. The incidence of missed fetal growth restriction cases, false-positive rate, and error were calculated along with the relative risk for a missed diagnosis using the smaller crown-rump length. RESULTS: A total of 176 subjects were screened: 81 had a fetal growth ultrasound at 24 to <32 weeks of gestation, and 58 had a fetal growth ultrasound at ≥32 weeks of gestation. There was a significant difference in the incidence of fetal growth restriction using the 3 dating strategies in both gestational age ranges (P<.001) with the smaller crown-rump length estimated due date more closely approximating the true rate. Before 32 weeks of gestation, the smaller crown-rump length estimated due date missed 2.5% of fetal growth restriction cases, whereas the larger crown-rump length estimated due date missed 0.6% of fetal growth restriction cases, with false-positive and error rates of 1.2% and 3.7% and 5.5% and 6.2%, respectively. After 32 weeks of gestation, the smaller crown-rump length estimated due date missed 1.8% of cases, whereas the larger crown-rump length estimated due date missed 0% of cases, with false-positive and error rates of 2.6% and 4.4% and 5.3% and 5.3%, respectively. The relative risk for a missed diagnosis of fetal growth restriction using the smaller crown-rump length estimated due date was 1.77 for early-onset growth restriction and 1.22 for late-onset growth restriction. CONCLUSION: Using the estimated due date derived from the smaller twin led to a more accurate detection of fetal growth restriction at a cost of a higher missed diagnosis rate.

Can Early First Trimester Ultrasounds Correctly Determine Gestational Age Compared to Ultrasounds Performed Between 7 to 14 Weeks Gestational Age?

OBJECTIVES: The Society of Obstetricians and Gynaecologists of Canada (SOGC) recommends the use of an ultrasound performed between 7 and 14 weeks gestation to accurately predict gestational age (GA). This study aimed to assess the accuracy of earlier ultrasounds (5 to 66 weeks gestation) by comparing the estimated delivery dates (EDD) in participants that had undergone both an earlier ultrasound and ultrasound completed during the standard of care timeframe. METHODS: EDD based on crown-rump length were retrospectively reviewed for patients that had undergone an ultrasound between 5-66 weeks GA versus the recommended 7-14 weeks GA at the Montfort Hospital during 2018 and 2019. The charts of 981 patients that had an ultrasound prior to 7 weeks GA and at 7-14 weeks GA were reviewed; 54 were included. RESULTS: There was no significant difference (P = 0.307) between the EDD of the early (5-66 weeks GA) and the second ultrasound (7-14 weeks GA). The first ultrasounds were then separated into very early (5-56 weeks GA) and early (6-66 weeks GA) and compared. No significant differences (P = 0.579) were found. Similarly, no difference was found between the EDD of the early (6-66 weeks GA) and standard of care timing (P = 0.324). CONCLUSION: These results show no significant difference in accurately determining the EDD between ultrasounds completed at the early and standard of care time points. This could result in cost-saving benefits by foregoing a repeat ultrasound; however, further research is required prior to applying these findings in clinical settings.

Surgical intervention after medical treatment for early pregnancy loss according to gestational size.

OBJECTIVE: To study the rate of surgical intervention for unsuccessful medical treatment in early pregnancy loss (EPL), according to gestational size by ultrasound (GS-US). METHODS: This was a retrospective cohort study. All women who were treated with misoprostol for EPL between July 2015 and December 2020 were included. The cohort was divided according to GS-US: group 1: gestational sac without an embryonic pole; group 2: an embryonic pole with crown-rump length (CRL) compatible with <7 weeks; group 3: CRL compatible with 7+0 -7+6 weeks; group 4: CRL compatible with 8+0 -8+6 weeks; group 5: CRL compatible with ≥9 weeks. We compared the rate of any surgical intervention due to treatment failure. RESULTS: Overall, 783 patients were included: group 1, 236 (30.1%); group 2, 319 (40.7%); group 3, 115 (14.7%); group 4, 78 (10.0%); and group 5, 35 (5.0%) patients. The rate of any surgical intervention was significantly lower in groups 1-4 (54, 22.9%; 85, 26.6%; 28, 24.3%; and 22, 28.2%, respectively) compared with group 5 (17, 48.6%; P = 0.030). On multivariant analysis, GS-US greater than 9 weeks was independently associated with the need for surgical intervention (adjusted odds ratio 1.23, 95% confidence interval 1.01-1.51; P = 0.040). CONCLUSION: When treating EPL medically, GS-US greater than 9 weeks increases the risk of undergoing additional surgical intervention compared with younger weeks.

Intertwin growth discordance throughout gestation and hypertensive disorders of pregnancy.

BACKGROUND: Previous studies have established the association between intertwin birthweight discordance and hypertensive disorders of pregnancy. However, longitudinal fetal size discordance concerning gestational hypertension or preeclampsia remains unclear. OBJECTIVE: This study aimed to compare the patterns of estimated fetal weight discordance throughout gestation among normotensive women, women with gestational hypertension, and women with preeclampsia and to evaluate the association between crown-rump length discordance at 11 to 14 weeks of gestation and hypertensive disorders of pregnancy. STUDY DESIGN: This was a retrospective cohort study of women with twin pregnancies who had antenatal care visits and delivered at a tertiary hospital between January 2013 and June 2021. The crown-rump length was measured at 11 to 14 weeks of gestation. Estimated fetal weight was calculated based on ultrasound examinations of fetal biometrics at 16 to 18, 20 to 24, 28 to 32, and ≥34 weeks of gestation, respectively. Crown-rump length and estimated fetal weight discordances were calculated: (larger crown-rump length - smaller crown-rump length)/larger crown-rump length × 100% and (larger estimated fetal weight - smaller estimated fetal weight)/larger estimated fetal weight × 100%, respectively. Multiple imputation was used to handle missing data, and all models accounted for the imputation. Multilevel model analysis was used to compare the differences in estimated fetal weight discordances throughout gestation among normotensive women, women with gestational hypertension, and women with preeclampsia. Generalized linear models were used to evaluate the association between crown-rump length discordance and hypertensive disorders of pregnancy, assuming a Poisson distribution. The possible nonlinear relationship between continuous crown-rump length discordance and hypertensive disorders of pregnancy was examined by generalized additive models. All analyses were stratified by chorionicity. RESULTS: Of the 3280 women with twin pregnancies who met the inclusion criteria, 187 (5.7%) developed gestational hypertension, and 436 (13.3%) developed preeclampsia, including 125 (3.8%) early-onset preeclampsia and 311 (9.5%) late-onset preeclampsia. In women with dichorionic twin pregnancies, compared with normotensive women, a substantial progression of estimated fetal weight discordance throughout pregnancy was identified in women who developed preeclampsia, and a large progression of estimated fetal weight discordance in late pregnancy was identified in women who developed gestational hypertension. In women with monochorionic twin pregnancies, estimated fetal weight discordances were more progressive from 20 to 24 weeks of gestation onward in women who developed preeclampsia than in normotensive women. Crown-rump length discordance at 11 to 14 weeks of gestation was associated with an increased risk of preeclampsia (relative risk, 1.03; 95% confidence interval, 1.00-1.05), particularly early-onset preeclampsia (relative risk, 1.09; 95% confidence interval, 1.04-1.13). A crown-rump length discordance of ≥10% had 1.2 times the increased risk of developing early-onset preeclampsia (relative risk, 2.27; 95% confidence interval, 1.28-4.03). This association was identified in dichorionic twins, but not in monochorionic twins. CONCLUSION: Our study demonstrated distinct growth discordant patterns among normotensive women, women with gestational hypertension, and women with preeclampsia in twin pregnancies. Intertwin crown-rump length discordance at 11 to 14 weeks of gestation was associated with an increased risk of preeclampsia, especially early-onset preeclampsia in dichorionic twin pregnancies, with a dose-response pattern.

Ductus venosus as a marker of fetal growth in first trimester in a population of Colombian pregnant women / Ductus venoso como marcador de crecimiento fetal en primer trimestre en una población de gestantes colombianas

Abstract Objectives: to evaluate the relationship between the ductus venosus (DV) and the variables of fetal growth in the first trimester in a Colombian pregnant population. Methods: a descriptive cross-sectional study was carried out with secondary data obtained from a multicenter study.526 patients were included between weeks 11 and 14 for gestational ultrasound follow-up attended in three health care institutions in Bogotá, Colombia, between May 2014 and October 2018. A bivariate descriptive analysis was carried out where the relationship between the characteristics of the DV in the first trimester and ultrasound findings. Results: the flow wave of the DV in the first trimester was normal in the entire sample, with a pulsatility index of the ductus venosus (DVPI) of 0.96±0.18. In addition, a negative correlation was found between the crown-rump length (CRL) and the DVPI (p<0.05). Conclusion: there is a relationship between the DVPI regarding the CRL, indicating an interest in this early marker in relation to fetal growth alterations; however, more studies are required to determine the usefulness of this variable with respect to fetal growth.

Resumen Objetivos: evaluar la relación entre el ductus venoso (DV) y las variables del crecimiento fetal en primer trimestre en una población de gestantes colombianas. Métodos: se realizó un estudio transversal descriptivo con datos secundarios obtenidos de un estudio multicéntrico. Se incluyeron 526 pacientes entre las semanas 11 a 14 para seguimiento ecográfico gestacional atendidas en tres instituciones prestadoras de salud en Bogotá, Colombia, entre mayo del 2014 y octubre del 2018. Se realizó un análisis descriptivo bivariado donde se evaluó la relación entre las características del DV en primer trimestre y los hallazgos ecográficos. Resultados: la onda de flujo del DV en primer trimestre fue normal en la totalidad de la muestra, con un índice medio de pulsatilidad del ductus venoso (IPDV) de 0,96±0.18. Se encontró una correlación negativa entre la longitud cefalocaudal (LCC) y el IPDV (p<0.05). Conclusión: existe una relación entre el IPDV respecto a la LCC, señalando un interés de este marcador temprano en relación con las alteraciones del crecimiento fetal, sin embargo, se requieren más estudios para determinar la utilidad entre esta variable respecto al crecimiento fetal

The Association between Intertwin Difference in First Trimester Crown-Rump Length, Nuchal Translucency, and Birth Weight Discordance in Twin Pregnancies: A Retrospective Cohort Study.

Background: Discordant birth weight in twins is linked to poor outcomes and predicting this discrepancy may lead to enhanced screening and surveillance. Our purpose was to quantify the relationship between intertwin nuchal translucency (NT) and crown-rump length (CRL) discordance with birth weight discrepancies ≥ 20%. Methods: We conducted a retrospective cohort study of 887 live twin births delivering at a Canadian tertiary care center over a 7-year period who opted for integrated prenatal screening. Categorical data are presented as numbers and percentages, and continuous data are expressed as means and standard deviations. Chi-square tests, Fisher's Exact tests, or T-test were performed as appropriate. We then used published data and receiver operating curves to determine the optimal thresholds for predicting birth weight discordance based on first trimester intertwin NT differences. These values were used in multivariate logistic regression models accounting for known confounders. Results: Roughly 16% of twin pairs exhibited ≥ 20% difference in birth weight. Twin pairs with a CRL discordance greater than 10% have nearly a 4 times greater likelihood of having a birth weight discordance greater than 20% (OR 3.71, CI 2.24-6.14) while controlling for chorionicity, maternal age, gestational age at delivery, maternal body mass index (BMI), and parity. In these models, intertwin NT discordance ≥ 20% (OR 1.16, CI 0.77-1.77) and NT discordance ≥ 14% (OR 1.08, CI 0.73-1.60) were not statistically significant predictors of twin birth weight differences. However, when evaluating the effect of the larger intertwin NT value corresponding to the 95th percentile, an NT difference ≥ 0.9 mm was predictive of birth weight discordance ≥ 20% (OR 2.53, CI 1.21-5.29). Conclusion: Although intertwin CRL and NT discordance measured via ultrasound between 11-14 weeks gestation are related to birth weight discordance, there is uncertainty as to whether twin birth weight differences are related to adverse pregnancy outcomes in this population.

Screening and diagnosis of chromosomal abnormalities in twin pregnancy.

Twin pregnancies are at an increased risk of adverse pregnancy and perinatal outcome as compared to singleton gestations, mainly as the consequence of the higher rate of preterm birth, chromosomal as well as structural anomalies, placental abnormalities, and complications unique to monochorionic placentation. Screening for chromosomal anomalies poses diagnostic and management challenges when applied to twin pregnancies. The recent implementation of cell-free fetal DNA (cffDNA) in clinical practice raises the questions whether a more accurate test should be offered to twin pregnancies in view of the higher false positive rate of traditional screening and the higher risk of fetal loss following amniocentesis or chorionic villus sampling (CVS) in multiple gestations. Finally, twin pregnancies require a tailored approach for aneuploidy screening, such as nuchal translucency (NT) or crown rump length discordance, discordant fetal anomalies, or monoamniotic gestations. The present review aims to provide an up-to-date critical appraisal of screening and prenatal diagnosis of chromosomal abnormalities in twin pregnancies.

Risk factors for missed abortion: retrospective analysis of a single institution's experience.

OBJECTIVE: To explore the risk factors including the difference between mean gestational sac diameter and crown-rump length for missed abortion. METHODS: Hospitalized patients with missed abortion and patients with continuing pregnancy to the second trimester from Chengdu Women's and Children's Central Hospital from June 2018 to June 2021 were retrospectively analyzed. The best cut-off value for age and difference between mean gestational sac diameter and crown-rump length (mGSD-CRL) were obtained by x-tile software. Univariate and multivariate logistic regression analysis were adopted to identify the possible risk factors for missed abortion. RESULTS: Age, gravidity, parity, history of cesarean section, history of recurrent abortion (≥ 3 spontaneous abortions), history of ectopic pregnancy and overweight or obesity (BMI > 24 kg/m2) were related to missed abortion in univariate analysis. However, only age (≥ 30 vs < 30 years: OR = 1.683, 95%CI = 1.017-2.785, P = 0.043, power = 54.4%), BMI (> 24 vs ≤ 24 kg/m2: OR = 2.073, 95%CI = 1.056-4.068, P = 0.034, power = 81.3%) and mGSD-CRL (> 20.0vs ≤ 11.7 mm: OR = 2.960, 95% CI = 1.397-6.273, P = 0.005, power = 98.9%; 11.7 < mGSD-CRL ≤ 20.0vs > 20.0 mm: OR = 0.341, 95%CI = 0.172-0.676, P = 0.002, power = 84.8%) were identified as independent risk factors for missed abortion in multivariate analysis. CONCLUSION: Patients with age ≥ 30 years, BMI > 24 kg/m2 or mGSD-CRL > 20 mm had increasing risk for missed abortion, who should be more closely monitored and facilitated with necessary interventions at first trimester or even before conception to reduce the occurrence of missed abortion to have better clinical outcomes.