Prevalence of velamentous and marginal umbilical cord insertions; a comparison of term singleton ART and non-ART pregnancies

Novel pathological findings of placenta with fetal heart failure associated with congenital heart disease

IUGR in rats is associated with changes in placental expression of MTAs

To investigate the relationship between abnormal umbilical cord insertion and birthweight discordance in monochorionic diamnionic (MCDA) twins. A total of 137 pairs of MCDAs were retrospectively analyzed who delivered and survived in Hangzhou Women’s Hospital from January 2016 to December 2021. According to different insertion methods, they were divided into normal cord insertion group (n = 57), marginal cord insertion (MCI) group (n = 34) and velamentous cord insertion (VCI) group (n = 46). The correlation was analyzed between different insertion methods of umbilical cord and the discordant birth weight of MCDAs. The gestational age of delivery with velamentous cord insertion was significantly earlier than those with normal and marginal insertion (P < .05). There were significant differences in birthweight between large fetus (F1) and small fetus (F2) with different umbilical insertion methods (P < .05). The birthweight of F1 and F2 in normal insertion group was significantly higher than those in MCI and VCI group (P < .05). Logistic regression analysis showed that VCI was significantly associated with birth weight in F1/F2, birthweight discordance ≥ 20%, and birthweight discordance ≥ 25%, however MCI and VCI were not an independent factor for discordance in birthweight of MCDAs (P > .05). Umbilical cord insertion method can lead to inconsistency in birthweight of MCDA twins, however they were not an independent factor for discordance in birthweight.

To assess perinatal outcome in type II monochorionic (MC) diamniotic twin pregnancies (DA) affected by selective intrauterine growth restriction (sIUGR) and abnormal cord insertion managed expectantly. A prospective longitudinal study from June 2008 and July 2011 on 24 MCDA sIUGR twins. sIUGR was defined as estimated fetal weight below the 10th percentile in one twin and was classified into three groups based on umbilical artery (UA) Doppler diastolic flow (I: presence; II: constantly absent/reverse (AEDF/ARED); III: intermittently absent or reverse). Marginal cord insertion was defined as insertion within 2 cm of the placental disc edge, and velamentous insertion as a cord insertion into the fetal membranes. Expectant management was chosen in these twins, and absent or reverse A wave in the ductus venosus (DV) was a criterion for delivery. Neonatal outcome was available for all twins delivered. Pathological examination and vascular cast of placentas were performed in all cases. Fourteen twin pregnancies were type II sIUGR, and ten presented an abnormal umbilical cord insertion. Median gestational age (GA) at diagnosis of sIUGR was 18 weeks' gestation (range 16-20 weeks), and all sIUGR co-twins showed AEDF of UA at a median gestational age of 20 weeks (range 18-22 weeks). Median gestational age at delivery was 30 weeks (range 28-34 weeks) with a median birth weight of 1285 g (range 307-1725 g). pH at birth and base excess (BE) were normal in all IUGR co-twin (pH>7.10, median BE 5.5); Apgar score at 5 min was >7. Perinatal outcome was favorable in all cases. Placental pathological examination confirmed the marginal insertion of the umbilical cord and the absence of anastomosis between the two portions of umbilical insertion. This study highlights that expectant management for sIUGR type II twins with or without an abnormal cord insertion should be a valid option to time delivery for these fetuses as shown by the favorable neonatal outcome.

In vitro fertilization is a risk factor for vasa previa

INTRODUCTION: Abnormal placental cord insertion has been associated with an increase in preterm delivery, low birth weight, neonatal intensive care admissions and cesarean delivery. Assisted reproductive technology (ART) has been associated with some similar placenta-medicated pregnancy complications. We hypothesize an increase in abnormal placental cord insertion in pregnancies conceived using ART, thereby contributing to the increased association of adverse pregnancy outcomes. METHODS: We performed an IRB approved, retrospective chart review of 3728 singleton and twin placentas sent to pathology at the University of Massachusetts between January 2011-January 2016. Placental pathology reports were reviewed and evidence of abnormal placental cord insertion, either velamentous or marginal, were recorded. Chi-square test was used for categorical variables and student T-test for continuous. Logistic regression was used to control for potential confounders. P less than 0.05 was used for statistical significance. RESULTS: Of the 3728 pregnancies, 3615 were conceived via spontaneous conception, whereas 113 were conceived through ART. Women who conceived with ART were more likely to be married, of white race, older and have multiple gestations than those with spontaneous conception. ART pregnancies were over 2-fold more likely to have abnormal placental cord insertions (OR 2.1 [1.1–3.9], P=.03). After adjusting for confounding factors, statistical significance was no longer noted. CONCLUSION: Pregnancies conceived with ART were more likely to have abnormal placental cord insertion in our study. A larger sample size of women conceived using ART would be needed to fully understand the effect of ART on abnormal placental cord insertion beyond the confounding effect of multiple gestations.

Introduction/PurposeIt is well‐documented in the literature that the placenta migrates during pregnancy; however, studies regarding placental cord insertion (PCI) migration are scarce. This longitudinal, prospective study aimed to determine whether PCI migration is a true phenomenon, to assess whether the PCI can change classification during pregnancy and to determine the validity of PCI site documentation including follow‐up of abnormal PCI.MethodsEighty‐three participants who had first, second and third trimester ultrasound examinations at a Western Australian private imaging practice over a 12‐month period between November 2021 and November 2022 were recruited. The measured distance of the lower margin of the placenta to the cervix, the distance of the PCI to the closest placental edge and the PCI classification were documented in each trimester. Data analysis was conducted to determine PCI migration rates during pregnancy and to test for association between PCI migration and maternal and placental factors.ResultsThe PCI migrated during pregnancy and the PCI classification has the potential to evolve. All identifiable PCIs that were normal in first trimester remained so throughout the pregnancy. The majority (67.6%) of cord insertions that were marginal in first trimester progressed to a normal insertion site by third trimester; 23.5% remained marginal and 8.8% evolved to a velamentous insertion. Three velamentous cord insertions were recorded in first trimester, none of which normalised—two remained velamentous during the pregnancy and one evolved to marginal in second trimester. Marginal cord insertions (MCIs) ≤10 mm from the placental edge in second trimester remained marginal in third trimester; MCIs that were >15 mm from the placental edge in second trimester normalised in third trimester.ConclusionsPlacental cord insertion migration is a phenomenon that occurs during pregnancy with the potential for PCI classification to evolve. Due to the association between abnormal PCI and perinatal complications, coupled with the potential for marginal cord insertion to evolve, documentation of PCI and follow‐up of abnormal PCI is beneficial, particularly in cases of velamentous insertion and marginal insertion at the placental edge or in the lower uterus.

Multiple pregnancy is associated with high perinatal mortality and morbidity. Abnormal cord insertions more common in twin pregnancies compared to singleton pregnancies and velamentous cord insertion is related with poor pregnancy outcomes. There is no definition of velamentous cord insertion into the intertwine membrane between two fetuses in the literature. In our single-center cross-sectional study, monochorionic-diamniotic and dichorionic-diamniotic twins who were admitted to our clinic between 18 + 0 and 23 + 6 weeks of pregnancy were enrolled in this study. We evaluated fetal, placental, and umbilical cord abnormalities in addition to fetal growth restrictions and weight discordance by ultrasonography. Although abnormal cord insertion frequency was significantly higher in monochorionic twins (p=0.003), intertwin membrane cord insertion could only occur in dichorionic twins. In cases with cord insertion anomaly; FGR and weight discordance was observed more frequently (p < 0.001 and p=0.003, respectively). Weight discordance, the presence of abnormal cord insertion and abnormal UAD were found as statistically significant predictors of FGR (p < 0.001, p=0.021, and p < 0.001, respectively). Intertwin membrane insertion is a novel umbilical cord insertion abnormality. The presence of abnormal umbilical cord insertion is a risk factor for poor pregnancy outcomes in twin pregnancies.

Abnormal placental cord insertion includes marginal and velamentous placental cord insertion. With the development of obstetric ultrasound, such abnormal placental cord insertion can be diagnosed prenatal, and the relationship between the abnormal placental cord insertion of prenatal diagnosis and the pregnancy outcome is to be investigated. We performed a prospective study of singleton and multiple pregnancies women undergoing obstetric ultrasonography between 20–24 weeks of gestation at Ewha Women's University Hospital from February 2019 to October 2020. For the characteristics of pregnant women and pregnancy outcome, continuous variables were expressed as mean ± standard deviation and were compared using Student's t-test, or median (IQR) using Mann-Whitney test. Abnormal placental cord insertion was confirmed in 23 cases (6.42%) after a total of 358 deliveries, which 18 cases (5.02%) of marginal cord insertion were found, and 5 cases (1.40%) of velamentous placental cord insertion. Preterm birth, pre-eclampsia, fetal anomaly, postpartum hemorrhage, SGA, and LBW were significantly increased. (P-value< 0.05). Delivery by primary Caesarean section, gestational diabetes mellitus, low APGAR score was not statistically significant, but showed a tendency to increase. The results are given in table 1. Abnormal placental cord insertion is associated with poor pregnancy outcomes. Detecting abnormalities in the placenta attachment area before delivery can improve the prognosis of pregnancy. More cohort study is needed to evaluate the effects of abnormal placental cord insertion and pregnancy outcome. VP44.13: Table 1. Association of abnormal placental cord insertion with pregnancy outcome Central cord insertion (n = 335) Abnormal cord insertion (n = 23)

Our study aims to evaluate the umbilical vein (UV) hemodynamic change in the prenatal cohort of pregnancies diagnosed with abnormal placental cord insertion (aPCI). From January 2022 to December 2022, the fetal umbilical cord insertion site was sonographically examined in singleton fetuses, and umbilical cord blood flow was calculated. The umbilical artery and UV Doppler flow indexes were assessed in cases of normal and abnormal cord insertion. Among 570 singleton fetuses between 18 + 0 and 40 + 6weeks of gestation in the final study, the umbilical vein blood flow (UVBF) in the 3 groups of normal umbilical cord insertions, marginal umbilical cord insertions, and velamentous umbilical cord insertions was 145.39ml/min, 146.18ml/min, and 93.96ml/min, respectively. UVBF was significantly lower in the velamentous cord insertion (VCI) group than in the other groups (P < 0.05). Compared with the normal cord insertions group, lower birth weight (2820 ± 527g vs. 3144 ± 577g, P < 0.05), delivery at an earlier gestational age (38.0 ± 1.55weeks vs. 38.8 ± 2.34weeks, P < 0.05), higher bicarbonate (25.08 ± 1.72mmol/L vs. 22.66 ± 4.05mmol/L, P < 0.05), and higher standard base excess (-1.14 ± 1.50mmol/L vs. -3.30 ± 3.22mmol/L, P < 0.05) were found in the VCI group. We observed lower UVBF volume with aPCI. Hence, we propose UVBF analysis to evaluate fetal aPCI according to UV hemodynamics as an advisory in prenatal care. This would be useful and improve obstetricians' clinical explanation about the potential prenatal consequences so that parents can opt for future prenatal care during 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.

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.

Adverse perinatal outcomes have been related to growth discordance in twin pregnancies—most often defined as a greater than 20% or 30% difference in birth weights. Both genetic and uteroplacental factors have been implicated. The investigators hypothesized that differing rates of maturation of transferred embryos are associated with discordant birth weights in dichorionic twin pregnancies resulting from assisted reproductive technology (ART). Participating in the study were 101 nulliparous women having dichorionic twin pregnancies that produced male-male or female-female infants. Thirty-eight conceived spontaneously without ovulation induction, and 63 followed in vitro fertilization and embryo transfer. Crown-rump length (CRL) was measured by ultrasonography at 9–11 weeks' gestation. Gestational age was estimated either from the maternal menstrual history as confirmed by ultrasound study of the larger fetus or from the day of oocyte retrieval. Women with ART-conceived twin pregnancies were significantly older than those with spontaneous pregnancies, but the groups did not differ in other respects. No significant differences were found between spontaneous and ART-conceived twin pregnancies with respect to percentage CRL discordance, percentage birth weight discordance, or the incidence of birth weight discordance exceeding 20%. There was a significant positive correlation between percentage CRL disparity and percentage birth weight discordance in ART-conceived pregnancies, but no such correlation was evident in spontaneous pregnancies. An abnormal umbilical cord insertion was comparably frequent in spontaneous and ART-conceived dichorionic twin pregnancies. Abnormal cord insertion was associated with more frequent percentage birth weight discordance and birth weight discordance exceeding 20% in both spontaneous and ART-conceived pregnancies. No significant differences in percentage CRL discordance were found between pregnancies with and those without abnormal cord insertion. These findings lead the investigators to conclude that, in ART-conceived dichorionic twin pregnancies, CRL disparity may be associated with birth weight discordance.

Objectives Assisted reproductive technologies (ART) may be associated with placental abnormalities including placenta previa, umbilical cord abnormalities, and placental abruption. Our study evaluates the relationship between ART and placental abnormalities compared with spontaneously conceived controls. Methods An IRB-approved cohort study was conducted including women who delivered between January 2013 and December 2018. We excluded delivery prior to 23weeks and known fetal anomalies. Patients were matched with controls (2:1) for parity, age, and mode of delivery. Controls were women who had spontaneously conceived and delivered immediately preceding and following the index delivery. The primary outcome was placental abnormalities found on both antenatal ultrasound and pathology in ART gestations compared with spontaneously conceived gestations. Results There were 120 ART pregnancies and 240 matched control pregnancies identified. The groups were similar for parity, BMI, comorbidities, number of multiples, mode of delivery, and female newborns. The ART group had a higher maternal age (37.1±5y vs. 30.0±5y; p<0.001), greater preterm birth (29 vs. 6%; p<0.001), and lower BW (2,928±803g vs. 3,273±586g; p<0.001). The ART group had a higher incidence of placenta previa on ultrasound (4.0 vs. 0.4%, p=0.01), adherent placentas at delivery (3 vs. 0% p=0.014), placental abruption (2 vs. 0%; p=0.04), as well asan increased rate of velamentous cord insertion (12 vs. 3%, p<0.001) and marginal cord insertion (28 vs. 15%, p=0.002). ART demonstrated a two-fold likelihood of abnormal placental pathology. Conclusions ART is associated with increased rate of placental abnormalities, including abnormal umbilical cord insertion and increased rates of adherent placentation. This information may be beneficial in planning and surveillance in patients with ART pregnancies.

ObjectivesTo determine the prevalence of, and risk factors for anomalous insertions of the umbilical cord, and the risk for adverse outcomes of these pregnancies.DesignPopulation-based registry study.SettingMedical Birth Registry of Norway 1999–2009.PopulationAll births (gestational age >16 weeks to <45 weeks) in Norway (623,478 singletons and 11,263 pairs of twins).MethodsDescriptive statistics and odds ratios (ORs) for risk factors and adverse outcomes based on logistic regressions adjusted for confounders.Main outcome measuresVelamentous or marginal cord insertion. Abruption of the placenta, placenta praevia, pre-eclampsia, preterm birth, operative delivery, low Apgar score, transferral to neonatal intensive care unit (NICU), malformations, birthweight, and perinatal death.ResultsThe prevalence of abnormal cord insertion was 7.8% (1.5% velamentous, 6.3% marginal) in singleton pregnancies and 16.9% (6% velamentous, 10.9% marginal) in twins. The two conditions shared risk factors; twin gestation and pregnancies conceived with the aid of assisted reproductive technology were the most important, while bleeding in pregnancy, advanced maternal age, maternal chronic disease, female foetus and previous pregnancy with anomalous cord insertion were other risk factors. Velamentous and marginal insertion was associated with an increased risk of adverse outcomes such as placenta praevia (OR = 3.7, (95% CI = 3.1–4.6)), and placental abruption (OR = 2.6, (95% CI = 2.1–3.2)). The risk of pre-eclampsia, preterm birth and delivery by acute caesarean was doubled, as was the risk of low Apgar score, transferral to NICU, low birthweight and malformations. For velamentous insertion the risk of perinatal death at term was tripled, OR = 3.3 (95% CI = 2.5–4.3).ConclusionThe prevalence of velamentous and marginal insertions of the umbilical cord was 7.8% in singletons and 16.9% in twin gestations, with marginal insertion being more common than velamentous. The conditions were associated with common risk factors and an increased risk of adverse perinatal outcomes; these risks were greater for velamentous than for marginal insertion.