Placental Cord Insertion Site Research Articles

Placental cord insertion migration: Implications for ultrasound documentation and follow‐up of abnormal placental cord insertion site

Placental cord insertion migration: Implications for ultrasound documentation and follow‐up of abnormal placental cord insertion site

Association of Placental Umbilical Cord Insertion Site with Maternal and Fetal Outcomes: A Prospective Study

Abstract Introduction Adequate fetal growth during pregnancy depends upon the normal development and insertion of the umbilical cord. Central/paracentral placental cord insertion is considered normal, while marginal/velamentous cord insertion is considered abnormal. Although the location of placental umbilical cord insertion can be determined by ultrasound (US), it is not included in the routine protocol of a targeted anomaly scan. Through this study, we determined different placental umbilical cord insertion sites by US and categorized them as normal and abnormal, identified the risk factors involved, and evaluated the outcome of pregnancies using standard protocols. The rationale of this study was to identify pregnancies that require frequent monitoring and surveillance for an optimal perinatal outcome. Methods A prospective cohort study was conducted in a tertiary care hospital for 18 months. A total of 345 pregnant women who attended the antenatal outpatient department between 18 and 22 weeks for targeted imaging for fetal anomalies scan were included in the study after informed consent. Detailed history followed by US documentation of the cord insertion site on the placenta was done and women were followed up throughout pregnancy to look for development of complications including hypertensive disorders, antepartum hemorrhage (APH), and fetal growth restriction (FGR). Intrapartum adverse events like fetal distress and intrapartum hemorrhage were assessed. Confirmation of US findings was done by macroscopic examination of the placenta and measuring the distance between the placental cord insertion and the edge of the placenta. The weight of the placenta was also documented. Newborns were evaluated for adverse outcomes like preterm birth, low birth weight, need for resuscitation, and neonatal intensive care unit (NICU) admission. Follow up of neonates and mothers was done till discharge. Results Placental cord insertion was accurately determined at the anomaly scan with 100% sensitivity and specificity. The study showed 44 abnormal placental cord insertions (ACIs)—42 had marginal and 2 had velamentous cord insertions. There was a high incidence of ACI noted in women aged more than 28 years, with body mass index of more than 26.38, multiparity, previous history of myomectomy, first trimester miscarriage, and conceived by assisted reproductive technology. Women with ACI had an increased risk of small for gestational age/FGR and APH and had an average baby weight of 2.7 kg, which was 200 g less than babies with normal cord insertion. They also had lower mean Apgar scores at 5 minutes and required resuscitation and NICU admission. Conclusion Our study concluded that it will be a good practice to document the placental cord insertion during the mid trimester anomaly scan so that we can identify the subset of pregnant women who are prone to develop complications, thereby providing adequate surveillance for an optimal perinatal outcome.

Analysis of placental surface cysts using ultrasonography: Histological and clinical correlation

AbstractObjectiveThis study aimed to investigate the diagnostic utility of ultrasonography, along with the clinical and histopathologic characteristics, and prognosis specifically related to placental surface cysts.MethodWe conducted a retrospective analysis of patients diagnosed with placental surface cysts at the Shengjing Hospital of China Medical University, between July 2010 and November 2022. Data were collected from a computer database of ultrasound images, and electronic medical records were reviewed. Placental cysts not located on the placental surface and cases where delivery occurred at outside institutions were excluded from the analysis.ResultsWe gathered data from 22 pregnant women who presented with placental surface cystic masses. These women had a mean age of 28.14 ± 3.04 years and the cysts were identified by ultrasound at a mean gestational age of 29 ± 5 weeks. The cysts were found to have varying sizes (ranging from 8 to 88 mm, with an average size of 47 ± 24 mm). Thirteen patients (59.09%) had cysts located near the placental cord insertion site (PCIS). All neonates, except for one case of induced labor, had favorable prognoses. The majority of the cysts were identified as amniotic cysts. Pathological diagnosis revealed degenerative changes in the placenta, with the cysts attributed to subchorionic fibrin formation by the central cyst.ConclusionPlacental surface cysts typically do not present with specific clinical symptoms and are diagnosed through ultrasound. It is important to note that this study specifically focused on placental surface cysts, excluding those not located on the placental surface. Regular ultrasound follow‐up is recommended, and the prognosis for placental surface cysts is excellent.

Association between placental location and cord insertion site with pre-eclampsia: a retrospective cohort study

Objective The relationship between placental location in pregnancies without previa and adverse pregnancy outcomes has not been well studied. Additionally, the impact of abnormal cord insertion sites remains controversial. Therefore, the objective of this study was to explore the adverse outcomes associated with placental location and abnormal cord insertion in nulliparous women and to assess their impact on pregnancy outcomes. Methods This retrospective cohort study was conducted at a single tertiary hospital between January 2019 and June 2022. The study included nulliparous women with singleton pregnancies who delivered live infants and had available data on placental location and umbilical cord insertion site from a second- or third-trimester ultrasound. Placental location was categorized as anterior or posterior using transabdominal ultrasonography. The association between placental location/cord insertion site and pre-eclampsia was evaluated using multivariate logistic regression analysis. We compared the area under the curve to evaluate the impact of placental location and cord insertion site on pre-eclampsia. Results A total of 2219 pregnancies were included in the study. Pre-eclampsia occurred significantly more frequently in the anterior group than in the posterior group (8.21% vs. 3.04%, p < .001). In multivariate analysis investigating the association between placental location and pre-eclampsia, anterior placenta and marginal cord insertion showed increased odds ratios for pre-eclampsia of 3.05 (95% confidence interval [CI] 1.68–6.58) and 3.64 (95% CI 1.90–6.97), respectively. Receiver operating characteristic (ROC) curves were constructed to predict pre-eclampsia using independent factors from multivariate analyses. Model I, including maternal age, pre-pregnancy body mass index, in vitro fertilization, chronic hypertension, overt diabetes, kidney disease, and hematologic diseases, achieved an area under the ROC curve of 0.70 (95% CI 0.65–0.75). Adding cord insertion site and placental location to the model (Model II) improved its predictive performance, resulting in an area under the ROC curve of 0.749 (95% CI 0.70–0.79, p = .02). Conclusions Anterior placenta and marginal cord insertion were associated with an increased risk of pre-eclampsia. Further studies on prospective cohorts are necessary to validate these findings.

Ultrasonographic correlation of placental thickness with some foetal biometry in seemingly normal singleton pregnancies in Taraba State, Nigeria

An accurate assessment of the gestational age (G.A) and evaluation of foetal growth is essential to antenatal care. GA prediction based on the sonographic foetal parameters may be the cornerstone in modern obstetrics and continues to remain an important component of the management of pregnancies. Placental thickness appears to be a promising parameter for the estimation of GA, for it tends to have a positive correlation with it. Ultrasonography helps in the assessment of the placenta and the detection of placental abnormalities using different parameters like placental thickness and volume. This study was conducted to sonographically measure the placental thickness and correlate it with some foetal biometry in apparently normal singleton pregnancies. A prospective cross-sectional design was employed for the study from March to July 2021 in Jalingo, Taraba State. A convenient sampling method was employed and included a total of 314 healthy pregnant women referred for obstetrics ultrasound scans in their 2nd and 3rd trimesters. Ultrasound scans were performed using an ultrasound system equipped with a 3.5 MHz curvilinear transducer. Findings from this study revealed an increasing trend in the values of the mean placental thickness with an increase in G.A, and the placental thickness in mm coincide almost exactly with the GA weeks, indicating there was a positive correlation between placental thickness and G.A from 14-35 weeks of gestation. However, placental thickness gradually declined from 36-40 weeks G. A, thereby, lagging behind the G.A marginally by 1-2 mm. Placental thickness cord insertion site can be used as an accurate sonographic parameter to determine the GA, especially from 14-35 weeks of gestation in apparently normal singleton pregnant women due to its statistically strong positive correlation with G.A.

Plasenta ve Umblikal Kord Özellikleri ile Fetal Distress Arasındaki İlişki

Aim: In our study, we investigated the relationship between placental thickness and weight, umbilical cord diameter and length, and placental cord insertion site with fetal distress, and its effects on the baby's APGAR score and cord blood gas.&#x0D; Materials and methods: In our study, the data of the patients who gave birth in our hospital, whose gestational patient was between 37+0- 41+6 weeks, and between the ages of 18-45 were recorded prospectively. 385 patients (196 patients fetal distress and 189 patients elective cesarean section) were included in the study. Demographic characteristics, placental thickness and weight, umbilical cord diameter and length, insertion site of the umbilical cord into the placenta, newborn gender, first- and fifth-minute. Apgar score, and umbilical cord blood gas values were recorded. All parameters were compared between both groups.&#x0D; Results: When both groups are compared, Maternal age (29.13 ± 5.20 vs. 25.67 ± 5.27, p

Current practice of placental cord insertion documentation in Australia - A sonographer survey.

During pregnancy, the umbilical cord attaches to the placenta in a central, eccentric, marginal or velamentous location. Maternal and fetal complications are associated with marginal and velamentous cord insertions, the most clinically significant being perinatal mortality due to undiagnosed vasa praevia. Current literature describes a wide variation regarding regulation of placental cord insertion (PCI) documentation during antenatal ultrasound examinations. This prospective cross-sectional study aimed to assess the current practice of antenatal PCI documentation in Australia. Members of the Australian Sonographer Accreditation Registry were invited to participate in an online survey which was distributed between February and March 2022. Four hundred ninety sonographers met the inclusion criteria for the study of which 330 (67.3%) have more than 10 years' experience as a sonographer and 375 (76.5%) are employed primarily in a public or private setting offering general ultrasound. Most respondents (89.6%) indicated documentation of the PCI site is departmental protocol at the second trimester anatomy scan (17-22 weeks gestation), but PCI documentation is protocol in less than 50% of other obstetric ultrasound examinations listed in the survey. The PCI site is included in the formal ultrasound report at a rate significantly less than inclusion in the departmental protocol and the sonographer's worksheet. Considering the potential maternal and fetal complications associated with abnormal PCI and the ease at which the PCI site is identified in the first and second trimesters, we believe that standard inclusion of the PCI site in departmental protocol and in the formal ultrasound report from 11 weeks gestation, regardless of whether it is normal or abnormal, would prove invaluable.

Influence of the placental cord insertion site on the placental mass and the birth weight in dichorionic diamniotic twins

The aim of the study was to determine the effect of the displacement of the umbilical cord insertion site from the centre of the placenta on the placental mass and the birth weight of dichorionic diamniotic twins and to consider the importance of the direction of the displacement, as well as to assess the influence of the umbilical cord displacement on the placental mass and the birth weight of dichorionic diamniotic twins taking into account the direction of displacement.&#x0D; Material and methods. The study was performed on 135 dichorionic diamniotic pairs: 68 opposite-sex, 35 same-sex males, and 32 same-sex females. The impact of an absolute cord displacement from the centroid of the placental disc and the direction of its shifting were compared with the birth weight and the placental mass.&#x0D; Results. In the investigated group, a central insertion was revealed in 6 (2.2 %), eccentric – in 224 (83.0 %), marginal – in 31 (11.5 %), and velamentous – in 9 (3.3 %) cases. The first two types of cord insertion are considered to be normal, the third and the fourth are seen as abnormal. The placental mass was in a strong positive correlation with the birth weight (r=0.71, p&lt;0.0001). The placentas with an eccentric cord insertion had a smaller surface area. A negative correlation was established between the displacement of the cord insertion site and the placental mass (r=-0.4284, p&lt;0.0001) as well as the birth weight (r=-0.6115, p&lt;0.0001). The shift along the long axis was of greater importance than in relation to the shorter one. The placental mass and the birth weight were higher in the new-borns with a normal cord insertion site. In the abnormal cord insertion group, 32.5 % of the infants were under the 10th birth weight percentile, in the normal cord insertion group – only 8.3 %.&#x0D; Conclusions. The birth weight of dichorionic diamniotic twins and their placental mass are negatively correlated with the distance of the umbilical cord insertion site from the placental centre. The insertion site displacement along the long axis has a stronger negative effect on the birth weight and the placental mass in comparison with the shifting along the short axis. The placentas with an eccentric cord insertion have a smaller surface area.

Prevalence of umbilical artery Doppler waveform abnormality during the early second trimester and the subsequent variation of waveforms in monochorionic diamniotic twin pregnancies: A prospective cohort study

To investigate the prevalence of qualitative abnormal umbilical artery Doppler waveforms (Abnormal UA) during the early second trimester and the subsequent variation of waveforms in monochorionic diamniotic (MCDA) twin pregnancies. This prospective cohort study included 153 MCDA twin pregnancies. Pulsed Doppler examinations for UA were performed at four points, including the free-loop (FL) and near the placental cord insertion site (CI) of each UA, between 16 and 17 weeks' gestation. Cases were classified into positive diastolic waveforms (Type I), persistent Abnormal UA (Type II), and intermittent Abnormal UA (Type III). When the diastolic velocity in UA Doppler was positive twice after different sequential recordings, the cases were determined to have achieved normalization. Follow-up Doppler examinations of the UA were performed at 24, 28, and 32 weeks' gestation. Of all 153 cases, 38 (25%; 19 Type II and 19 Type III cases) showed Abnormal UA at the first examination. Abnormal UA was detectable at FL in all selective intrauterine growth restriction (sIUGR) cases, whereas it was noted only at CI site in some non-sIUGR cases. Abnormal UA normalized in 12 (63%) Type II and 15 (79%) Type III cases. A quarter of MCDA twin pregnancies in the early second trimester demonstrated Abnormal UA. In MCDA twins with Abnormal UA between 16 and 17 weeks' gestation, it is preferable to follow them up to consider the possibility of normalization of Abnormal UA as well as features of UA waveforms specific to FL and CI.

Large Subchorionic Cyst Located at Umbilical Cord Insertion with Vascular Displacing and Intracystic Hemorrhage/Hematoma: A Case Report

Background: Large subchorionic cysts usually arise close to the placental cord insertion site (PCIS) inducing traction on the umbilical cord, impairing blood flow and favoring fetal growth restriction (FGR). Intracystic hemorrhage/hematoma is likely due to the prothrombotic properties of X cells secretion (extravillous trophoblast), which line the cyst wall. Case report: We describe a large subchorionic cyst located exactly at the PCIS, displacing the umbilical cord vessel branches running along the cyst surface. The fetus presented with FGR. At 36 weeks of gestational age, the cyst measured 7.7 cm in maximum dimension showing a partially organized hemorrhage and a peripheral laminated thrombohematoma. The patient underwent elective cesarean section as the cyst and its vessels were at high risk of rupture during labor. Conclusion: Recognition of large subchorionic cysts close to or at the PCIS in a growth restricted fetus with subsequent expedited delivery may avoid a fatal event.

Risk Factors for Co-Twin Fetal Demise following Radiofrequency Ablation in Multifetal Monochorionic Gestations

Background: Umbilical cord occlusion via radiofrequency ablation (RFA) is utilized to maximize outcomes of the co-twin in complicated multifetal monochorionic (MC) gestations. However, post-procedure co-twin fetal demise is of concern. Objective: The aim of this study was to determine risk factors for co-twin fetal demise following RFA. Methods: This is a retrospective study of MC multiples that underwent RFA. Indications for RFA included twin reversed arterial perfusion (TRAP) sequence, selective fetal growth restriction (sFGR) type II, discordant lethal anomalies, and twin-twin transfusion syndrome (TTTS) with proximate placental cord insertion sites. The primary outcome was co-twin fetal demise. Bivariate analyses and multiple logistic regression modeling of identified risk factors were conducted. Results: Of 36 patients studied, surgical indications were: TRAP (n = 15, 41.7%), sFGR (n = 10, 27.8%), discordant anomalies (n = 9, 25.0%), and TTTS (n = 2, 5.6%). Nine patients (25.0%) experienced a co-twin fetal demise. In multiple logistic regression analysis, fetal growth restriction (FGR) of one co-twin was associated with increased risk of co-twin fetal demise (OR = 10.85, 95% CI 1.03–114.48, p = 0.0474) and a preoperative diagnosis of TRAP was protective against fetal demise (OR = 0.06, 95% CI 0.00–0.84, p = 0.0368). Conclusion: Co-twin FGR was associated with an increased risk of post-RFA demise. When compared to other indications, patients with TRAP sequence were less likely to have a co-twin demise.

Marginal placental cord insertion: the need for follow up?

Objective The objectives of this study were (1) to estimate the association between marginal placental cord insertion (PCI) and small for gestational age (SGA) and other adverse perinatal outcomes and (2) to determine if pregnancy-associated plasma protein A (PAPP-A) levels was altered in these patients. Methods It was a retrospective cohort study of singleton pregnancies undergoing ultrasound between 2016 and 2018. Marginal PCI was defined as a distance of ≤2 cm from placental edge to PCI site, visualized in both sagittal and transverse planes, and diagnosed between 16 and 32 weeks. Velamentous PCI were excluded. The primary outcome was SGA, defined as birthweight below 10th percentile for gestational age. Pregnancies with marginal PCI were compared to those with normal PCI with respect to maternal characteristics, PAPP-A levels and adverse perinatal and delivery outcomes. Results The incidence of marginal PCI was 4.2% (76/1819). Compared to those with a normal PCI, patients with a marginal PCI were more likely to be nulliparous and less likely to be African American or morbidly obese (p < .05). SGA rate was similar between the groups (17.6% vs. 18.1%). There was a trend toward an increased incidence of oligohydramnios, polyhydramnios and breech presentation in patients with marginal PCI; however, these did not reach statistical significance. The incidence of low PAPP-A level was comparable between the groups (18.4% vs. 14.3%, p > .05). Conclusion Our study did not demonstrate any increase in adverse pregnancy outcomes in the presence of marginal PCI. These findings may provide reassurance for counseling patients with this sonographic finding.

Antenatal Detection of Abnormal Placental Cord Insertion across Different Trimesters: A Prospective Cohort Study.

This article prospectively examines the use of ultrasound for antenatal detection of abnormal placental cord insertion (PCI) and compares the antenatal classification with delivered placental classification. This prospective cohort study examined 277 singleton pregnancies in a tertiary center. Scans were performed between 10 and 14, 18 and 22, and 32 and 34 weeks where PCI site was identified and its shortest distance to margin measured. Standardized images of delivered placentas were taken and digitally measured. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of antenatal classification compared with delivered placental classification were calculated. Abnormal PCI (distance < 2 cm from margin) was confirmed in 30/277 (11%) placentas at delivery. Note that 102/277 (37%) of PCI sites were classified as abnormal in the first trimester (T1), 43/277 (16%) in the second trimester (T2), and 28/277 (10%) in the third trimester (T3). Sensitivity (73%) and specificity (91%) were highest at T2. The PPVs were low (22% in T1, 51% in T2, and 64% in T3) and the NPVs were high (96% in T1 and 97% in both T2 and T3) for all scans. Abnormal PCI can be detected antenatally with optimal agreement with postnatal classification in T2. However, the incidence is overestimated at early scans with low PPVs.

Small for gestational age infants and the association with placental and umbilical cord morphometry: a digital imaging study

Introduction: Individual placental and umbilical cord morphometry have been previously identified to have an association with fetal growth. This study aims to identify which of the morphometric measurements in combination are associated with pregnancies with small for gestational age (SGA) infants using digital imaging of the delivered placenta.Material and methods: This study examined 1005 placentas from consecutively delivered singleton pregnancies in a tertiary center. Standardized images of each placenta were taken. Placental weight and thickness; umbilical cord length and diameter were measured on gross examination. Distance from the placental cord insertion site to placental margin, length and breadth of the placenta and placental chorionic surface area were measured digitally using ImageJ software. Logistic regression models and area under the curve (AUC) were used to identify the best subset of morphometric measurements to classify infants as SGA (<10th centile).Results: Overall, 141 (14%) infants were SGA. The morphometric measurements at delivery most strongly associated with the classification of infants as SGA were placental weight (AUC = 0.806) and placental surface area (AUC = 0.749). Of the potential antenatal morphometric measurements, umbilical cord diameters, both placental (AUC = 0.644) and fetal end (AUC = 0.629) were most strongly associated with SGA. A logistic regression model with maternal age, smoking status, current history of preeclampsia, umbilical cord length, placental weight, birthweight-to-placental weight ratio and umbilical cord diameter (placental end) had a sensitivity of 53% and a false-positive rate of 2% (AUC = 0.945) for the classification of infants as SGA.Conclusion: Placental and umbilical cord morphometry measured at delivery are different between SGA and non-SGA infants. Further studies are warranted to investigate the feasibility and accuracy of ultrasound to measure placental and umbilical cord morphometry during pregnancy.

117: Antenatal detection of abnormal placental cord insertion in each trimester: A prospective cohort study

Abnormal placental cord insertion (PCI) had been associated with adverse pregnancy outcomes such as small for gestational age and preterm labor. We aim to examine the use of ultrasound for antenatal detection of abnormal PCI in each trimester. This prospective cohort study examined 277 singleton pregnancies in a tertiary center. Scans were carried out between 10-14 weeks, 18-22 weeks and 32-34 weeks. The shortest distance of PCI site to the placental margin was identified and measured at each scan. A distance of less than 2 cm from the margin was categorized as abnormal PCI. Standardized images of delivered placentas were taken, and distance of the PCI site to the placental margin was measured digitally using ImageJ software. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the antenatal classification in each trimester with the delivered placental classification were calculated. Abnormal PCI was confirmed in 30/277 (11%) of placentas at delivery. Figure 1 compares the percentage classified as having abnormal PCI at each scan with the percentage at delivery. Both scan 1 and 2 over-estimated the incidence of abnormal PCI. Sensitivity and specificity were highest at scan 2 (73% and 91% respectively, see Table 1) but almost half of those identified as having abnormal PCI at scan 2 had normal PCI at delivery. It is feasible to detect abnormal PCI on ultrasound in each trimester of pregnancy, with the optimal agreement with PCI at delivery in the second trimester. However, the incidence of abnormal PCI is over-estimated at earlier scans and PPVs are low, thus we were unable to recommend the use of ultrasound to identify abnormal PCI during pregnancy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

AIUM-ACR-ACOG-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetric Ultrasound Examinations.

AIUM-ACR-ACOG-SMFM-SRU Practice Parameter for the Performance of Standard Diagnostic Obstetric Ultrasound Examinations.

Significance of placental cord insertion site in twin pregnancy.

To investigate the association between abnormal cord insertion and the development of twin-specific complications, including birth-weight discordance, selective fetal growth restriction (sFGR) and twin-to-twin transfusion syndrome (TTTS). This was a single center retrospective cohort study of twin pregnancies. Abnormal cord insertion was defined as either marginal (umbilical cord attachment site less than 2 cm to the nearest margin of the placental disc) or velamentous (cord attached to the membrane before reaching the placental disc with clear evidence of vessels traversing the membranes to connect with the placental disc), as described in placental pathology reports. Twins with major structural or chromosomal abnormalities and monochorionic monoamniotic twins were not included in the study. Information on the pregnancies, ultrasound findings, prenatal investigations and interventions was obtained from the electronic ultrasound database, while data on placental histopathological findings, pregnancy outcome, mode of delivery, birth weight, gestational age at delivery and admission to the neonatal intensive care unit were obtained from maternity records. Categorical variables were compared using the chi-square or Fisher's exact test, while continuous variables were compared using the Student's t-test, ANOVA for multiple comparisons and the Kruskal-Wallis test. Of the 497 twin pregnancies included in the analysis, 351 (70.6%) were dichorionic and 146 (29.4%) were monochorionic. The incidence of birth-weight discordance of 25% or more was significantly higher in pregnancies with velamentous and those with marginal cord insertions compared to those with normal cord insertion (24.0%, 15.3% vs 7.6%, P< 0.001 and P= 0.020, respectively). In pregnancies with birth-weight discordance of 25% or more, the smaller twins had significantly higher prevalence of velamentous (13.8%) and marginal (34.2%) cord insertions compared with the larger twins (1.8% and 18.5%, respectively, P< 0.001). The smaller twins of the monochorionic diamniotic pregnancies showed an even higher prevalence of velamentous (29.5%) and marginal (40.9%) cord insertions compared with the larger twins (2.3% and 31.5%, respectively, P< 0.001). Compared with the normal cord insertion group, only velamentous insertion was associated significantly with the risk of sFGR (odds ratio (OR), 9.24 (95% CI, 2.05-58.84), P< 0.001) and birth-weight discordance of 20% or more (OR, 4.34 (95% CI, 1.36-14.61), P= 0.007) and 25% or more (OR, 6.81 (95% CI, 1.67-34.12), P= 0.003) in monochorionic twin pregnancies. There was no significant association between velamentous cord insertion and TTTS (P= 0.591), or between marginal cord insertion and the development of sFGR (P= 0.233), birth-weight discordance of 25% or more (P= 0.114) or TTTS (P= 0.487). Subgroup analysis of dichorionic twins showed that abnormal cord insertion was not associated with the risk of birth-weight discordance (P= 0.999), sFGR (P= 0.308), composite neonatal adverse outcome (P= 0.637) or intrauterine death (P= 0.349). Monochorionic twins with velamentous cord insertion are at increased risk of birth-weight discordance and sFGR. Sonographic delineation of placental cord insertion could be of value in the antenatal stratification of twin pregnancies. Prospective studies are required to assess the value and predictive accuracy of this potential screening marker. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Preoperative Ultrasound Prediction of Essential Landmarks for Successful Fetoscopic Laser Treatment of Twin-Twin Transfusion Syndrome

Introduction: The insertion site of the fetoscope for laser occlusion (FLOC) treatment of twin-twin transfusion syndrome (TTTS) determines the likelihood of treatment success. We assessed a standardized preoperative ultrasound approach for its ability to identify critical landmarks for successful FLOC. Methods: Three surgeons independently performed preoperative ultrasound and deduced the likely orientation of the intertwin membrane (ITM) and vascular equator (VE) based on the sites of the cord insertion, the lie of the donor, and the size discordance between twins. At FLOC, these landmarks were visually verified and compared to preoperative assessments. Results: Fifty consecutive FLOC surgeries had 127 preoperative assessments. Basic ITM and VE orientation were accurately predicted in 115 (90.6%), 109 (85.8%), and 105 (82.7%) assessments. Predictions were anatomically correct in 96 (75.6%), 70 (55.1%), and 58 (45.7%) assessments with no differences in accuracy between operators of different training level. The ITM/VE relationship was most poorly predicted in stage-3 TTTS (χ², p = 0.016). Conclusion: In TTTS, preoperative ultrasound identification of placental cord insertion sites, lie of the donor twin, and size discordance enables preoperative prediction of key landmarks for successful FLOC.

Second trimester marginal cord insertion is associated with adverse perinatal outcomes

Objectives: To determine the feasibility in visualizing placental cord insertion (PCI) during second-trimester fetal anatomical survey and the association between marginal cord insertion (MCI) and preterm delivery (PTD) and low birth weight (LBW). Our secondary objectives were to evaluate the association of MCI with adverse composite obstetrical and neonatal outcomes.Methods: A prospective cohort study was performed over a 28-month period. Women with singleton pregnancies presenting for routine anatomical survey between 18 and 22 weeks’ gestation were included. PCI site was visualized on 2D grayscale and color Doppler and the shortest distance from the sagittal and transverse planes to the placental edge were recorded. MCI was diagnosed when any of measured distances was ≤2 cm. Correlations were assessed via bivariate chi-squared, independent t-test analyses and Fisher’s exact tests. Regression models evaluated associations between MCI and adverse composite outcomes.Results: Three hundred one women were included and PCI was feasible in all cases. The incidence of MCI was 11.3% (n = 34). Baseline characteristics between those with and without MCI were similar, except for story of prior PTD, which was greater among those with MCI (17.65 versus 7.17%, p = .04). MCI was associated with increased likelihood of LBW (RR four; 95%CI, 1.46–10.99) and PTD (RR 3.2; 95%CI, 1.53–6.68); in multivariate analysis, we found associations between MCI and composite adverse obstetrical (RR 2.33; 95%CI, 1.30–4.19) and neonatal (RR 2.46; 95%CI, 1.26–4.81) outcomes.Conclusions: Evaluation of PCI is feasible in all cases. Second-trimester MCI is associated with increased likelihood for LBW, PTD, and composite adverse obstetrical and neonatal outcomes.

P29.05: Placental cord insertion site and adverse pregnancy outcome in twin pregnancy

Abnormal umbilical cord insertion has been associated with unequal sharing of the placental vasculature between twins. A higher prevalence has been reported in pregnancies complicated by selective growth restriction (sFGR), birth weight discordance (BWD). We aimed to investigate the association between cord insertion site and adverse pregnancy outcomes in twin pregnancies. A single-centre cohort study of twin pregnancies that had placental histology. Higher-order multiples, major fetal anomaly, aneuploidy and MCMA pregnancies were excluded. Cord insertion site was categorised into 3 groups: marginal (attachment <2cm to the placental margin), velamentous (attached to the membrane before reaching the placenta with vessels traversing the membranes), normal. Chorionicity, placental weight, number of cord vessels, examination of the membranes, ultrasound findings, maternal characteristics and pregnancy outcome were collected. 546 pregnancies were eligible; 497 (146 monochorionic; 351 dichorionic) were included in the analysis. Significant differences were found between the normal and abnormal cord insertion groups with regards to BWD (P=0.001), BWD>25% (P=0.001), and absolute Z-score differences (P=0.020). Velamentous, but not marginal, cord insertion was significantly associated with sFGR (OR 8.51,95%CI 2.09-34.58;P=0.03) and BWD>25% (OR 11.88,95%CI 3.54-39.79;P=0.04). In MCDA, but not DCDA pregnancies, the rate of composite adverse outcome was higher in those with abnormal cord insertion (70.0% vs 53.0%, p=0.04). Selective fetal growth restriction and birthweight discordance are more common in twin pregnancies with abnormal cord insertion. MCDA twins with velamentous cord insertion are at increased risk of sFGR, and composite adverse pregnancy outcome.