Clinical Outcome of Monochorionic Diamniotic Twins with Intrauterine Growth Restriction.

OBJECTIVE: This study investigated the clinical outcome of monochorionic diamniotic (MCDA) twins with selective intrauterine growth restriction (sIUGR). STUDY DESIGN: International Peace Maternal and Child Health Hospital of Shanghai ultrasound database was investigated to identify all MCDA delivered from January 2013 to December 2017. After identifying 43 pairs of MCDA twins with sIUGR and 282 pairs of normal MCDA twins, we compared clinical outcomes between the two groups. RESULTS: Compared with normal twins, sIUGR fetuses had significantly shorter gestational age at delivery, smaller average birth weight of both twins, more significant intertwin difference in birth weight, lower Apgar scores, and higher intrauterine fetal demise (IUFD) rate, and smaller placental weight. The rate of abnormal umbilical cord insertions and abnormal blood flow in the ductus venosus (DV) and middle cerebral artery (MCA) is significantly higher in the sIUGR group. In addition, the subtype analysis of sIUGR groups indicated the poorest outcomes in type II with no significant difference between type I and III. CONCLUSION: MCDA twins with sIUGR generally exhibited limited clinical outcomes than normal MCDA twins. These limitations are mainly associated with abnormal umbilical cord insertions and blood flow in the DV and MCA. Clinical outcomes differed among the three types of sIUGR, with type II having the worst prognosis and the highest IUFD rate. KEY POINTS: · sIUGR generally exhibited limited clinical outcomes than normal MCDA twins.. · These limitations are mainly associated with blood flow of the DV and MCA.. · sIUGR with type II has the worst prognosis and the highest IUFD rate..

Fetal heart rate evolution patterns in cerebral palsy associated with umbilical cord complications: a nationwide study.

BACKGROUND: The aim of the present study was to clarify fetal heart rate (FHR) evolution patterns in infants with cerebral palsy (CP) according to different types of umbilical cord complications. METHODS: This case-control study included children born: with a birth weight ≥2000 g, at gestational age ≥33 weeks, with disability due to CP, and between 2009 and 2014. Obstetric characteristics and FHR patterns were compared among patients with CP associated with (126 cases) and without (594 controls) umbilical cord complications. RESULTS: There were 32 umbilical cord prolapse cases and 94 cases with coexistent antenatal umbilical cord complications. Compared with the control group, the persistent non-reassuring pattern was more frequent in cases with coexistent antenatal umbilical cord complications (p = 0.012). A reassuring FHR pattern was observed on admission, but resulted in prolonged deceleration, especially during the first stage of labor, and was significantly identified in 69% of cases with umbilical cord prolapse and 35% of cases with antenatal cord complications, compared to 17% of control cases (p < 0.001). CONCLUSION: Hypercoiled cord and abnormal placental umbilical cord insertion, may be associated with CP due to acute hypoxic-ischemic injury as well as sub-acute or chronic adverse events during pregnancy, while umbilical cord prolapse may be characterized by acute hypoxic-ischemic injury during delivery.

Heterotopic Liver Nodule Compressing a Two-Vessel Umbilical Cord: An Unusual Cause of Intrauterine Fetal Demise.

Heterotopic liver tissue in the umbilical cord is rare, and the outcome is quite unpredictable based on the few reported cases. We present a case of heterotopic liver nodule in the umbilical cord of a midtrimester fetus who died in utero. Although such association has only been reported once, heterotopic nodular tissue in the umbilical cord must be regarded as a potential cause of fetal demise by a mechanism analogous to the more common umbilical cord abnormalities resulting in umbilical vessel compromise.

Marginal cord insertion among singleton births at the University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia.

BACKGROUND: Umbilical cord may insert abnormally i.e. marginal insertion to a placenta which can cause different birth and perinatal complications. Despite the increased effort taken by different responsible bodies, the prevalence of birth and perinatal complications are still high, possibly due to anomalous cord insertion. So far, anomalous cord insertion lacks proper attention in different medical settings. Hence, the present study aims to assess the magnitude, risk factors, and adverse birth outcomes of marginal cord insertion among singleton births. METHODS: An institution-based cross-sectional study design was conducted. A systematic random sampling technique was used to select study participants. Data were collected by using a structured questionnaire and it was entered into epi-data version 3.1 then exported to SPSS version 20 for data cleansing and analysis. Bi-variable and multivariable logistic regressions were employed to identify risk factors and adverse outcomes associated with marginal cord insertions. Crude and adjusted odds ratio (P-value < 0.05) with a 95% confidence interval were calculated. RESULT: The magnitude of marginal cord insertion was 6.4% (95% CI = 4.4-8.8%) in singleton pregnancies. Independent risk factors for marginal cord insertion were advanced maternal age (AOR = 2.24, 95% CI: 1.35-11.08), primiparity (AOR = 1.98, 95% CI: 1.37-8.69), maternal chronic hypertension (AOR = 3.07, 95% CI: 1.66-9.76), previous cesarean delivery (AOR = 2.51, 95% CI: 1.43-10.21), and use of intrauterine contraceptive device before pregnancy (AOR = 2.22, 95% CI: 1.36-12.30). Pregnancies complicated by marginal cord insertion are at higher risk to develop low birth weight (AOR = 2.89, 95% CI: 1.23-6.80), preterm birth (AOR = 4.00, 95% CI: 1.44-11.14), and emergency cesarean delivery (AOR = 3.68, 95% CI: 1.03-13.81). CONCLUSION AND RECOMMENDATION: Marginal cord insertion is a mistreated potential risk for low birth weight, preterm birth, and emergency cesarean delivery. Routine screening of marginal cord insertion should be considered in pregnancies with advanced age, nulliparity, hypertensive disorder, history of cesarean section, and intrauterine contraceptive device usage before pregnancy.

10 cases of umbilical cord thrombosis in the third trimester.

BACKGROUND: Thrombosis of umbilical vessels is a rare occurrence that is difficult to detect during routine antenatal examinations but can lead to poor perinatal outcomes. OBJECTIVE: The aim of this study is to examine the association between meaningful clinical manifestations and features associated with thrombosis of umbilical vessels, and to evaluate optimal management options. METHODS: A retrospective study of umbilical cord thrombi cases enrolled between 2015-2019 was carried out. Data were analyzed from the medical archives where the diagnosis of all cases was established by histopathology. RESULTS: Gross examination reported additional cord abnormalities (7/10), including the irregular length of the umbilical cord, narrowed cord with hyper-coiling, swollen cord with deficiency of Wharton's jelly, placenta velamentous and umbilical infarction. Pathological examination accounted for 10 cases of umbilical cord thrombosis including umbilical artery embolism (3/10), umbilical vein thrombi (5/10) and funisitis (2/10). Clinical findings depicted that the chief complaint was decreased fetal movement companied by nonreactive NST tests (5/10). With the exception of two stillbirths, the remaining pregnancies (8/10) were terminated by cesarean section. All neonates are alive, including one VLBW and three LBW cases. CONCLUSION: We have observed that umbilical structural dysplasia, maternal coagulation disorder, vascular endothelial injury and elevated blood glucose may lead to the formation of thrombosis. Focus on specific signs during a prenatal ultrasound, EFM monitoring and counting fetal movements can help in early identification of umbilical cord thrombi. Our results support the more effective approach of emergency cesarean section during the third trimester.

Fetal heart rate pattern in term or near-term cerebral palsy: a nationwide cohort study.

BACKGROUND: It is crucial to interpret fetal heart rate patterns with a focus on the pattern evolution during labor to estimate the relationship between cerebral palsy and delivery. However, nationwide data are not available. OBJECTIVE: The aim of our study was to demonstrate the features of fetal heart rate pattern evolution and estimate the timing of fetal brain injury during labor in cerebral palsy cases. STUDY DESIGN: In this longitudinal study, 1069 consecutive intrapartum fetal heart rate strips from infants with severe cerebral palsy at or beyond 34 weeks of gestation, were analyzed. They were categorized as follows: (1) continuous bradycardia (Bradycardia), (2) persistently nonreassuring, (3) reassuring-prolonged deceleration, (4) Hon's pattern, and (5) persistently reassuring. The clinical factors underlying cerebral palsy in each group were assessed. RESULTS: Hypoxic brain injury during labor (those in the reassuring-prolonged deceleration and Hon's pattern groups) accounted for 31.5% of severe cerebral palsy cases and at least 30% of those developed during the antenatal period. Of the 1069 cases, 7.86% were classified as continuous bradycardia (n=84), 21.7% as persistently nonreassuring (n=232), 15.6% as reassuring-prolonged deceleration (n=167), 15.9% as Hon's pattern (n=170), 19.8% as persistently reassuring (n=212), and 19.1% were unclassified (n=204). The overall interobserver agreement was moderate (kappa 0.59). Placental abruption was the most common cause (31.9%) of cerebral palsy, accounting for almost 90% of cases in the continuous bradycardia group (64 of 73). Among the cases in the Hon's pattern group (n=67), umbilical cord abnormalities were the most common clinical factor for cerebral palsy development (29.9%), followed by placental abruption (20.9%), and inappropriate operative vaginal delivery (13.4%). CONCLUSION: Intrapartum hypoxic brain injury accounted for approximately 30% of severe cerebral palsy cases, whereas a substantial proportion of the cases were suspected to have either a prenatal or postnatal onset. Up to 16% of cerebral palsy cases may be preventable by placing a greater focus on the earlier changes seen in the Hon's fetal heart rate progression.

Umbilical cord hypercoiling in two rhesus macaques (Macaca mulatta).

Obstruction of umbilical blood flow is a common cause of death in fetal nonhuman primates, but cord accidents have not been reported in the macaque. We describe two cases of cord accident in rhesus macaques (Macaca mulatta) resulting in fetal death at approximately 110 and 50 days of gestation, respectively.

Pathoanatomical Lesions in Placentas With Excessively Hypercoiled Umbilical Cords: Frequent Detection of Massive Perivillous Fibrin Deposition.

This study focused to investigate a possible association of extensive umbilical hypercoiling (displaying an umbilical coiling index [UCI] of at least 1.0 coils/cm), clinical outcome, and associated pathoanatomical placental lesions. Of the 771 singleton placentas from the second and third trimesters submitted for pathoanatomical evaluation, 15 cases (2%) displayed extensive hypercoiling. There was an association of excessive hypercoiling with hypotrophy of fetuses and children (11 cases) and fetal demise (12 cases). Thin cord syndrome and umbilical stricture were observed in 9 cases and 4 cases, respectively. Seven of the 15 cases with excessive umbilical hypercoiling showed increased placental fibrin deposition (47% of the cases with hypercoiling), in 4 cases sufficient for rendering the diagnosis of massive perivillous fibrin deposition. Signs of maternal vascular malperfusion (n = 6) and chorangiosis (n = 2) were also detected in cases with hypercoiling. Recurrence of excessive umbilical hypercoiling was observed in 2 families, suggesting a genetic predisposition for the development of this lesion. Extensive hypercoiling could be a hitherto underrecognized pathogenetic factor for the development of massive perivillous fibrin deposition. A high UCI measured in the second trimester by ultrasound may be predictive of fetal hypotrophy, and intensified fetal monitoring is warranted, particularly if there is a history of hypercoiling and adverse fetal outcome.

Impact of first trimester determination of abnormal cord insertion on twin-to-twin transfusion syndrome and other adverse outcomes in monochorionic diamniotic twins: A retrospective cohort study.

OBJECTIVE: To assess the influence of abnormal cord insertion (CI) detected by first trimester ultrasonography on the development of twin-to-twin transfusion syndrome (TTTS) in monochorionic diamniotic (MCDA) twins. METHOD: In this retrospective cohort study, consecutive patients with MCDA twins who underwent fetal ultrasound screening in the first trimester between January 2011 and January 2017 were enrolled. The CI sites were evaluated between 11 + 0 and 13 + 6 weeks' gestation. All twin pairs were assigned to the abnormal CI group (twin pair with velamentous cord insertion (VCI) and/or marginal cord insertion (MCI) in one or both twins) or the normal CI group (twin pair with both normal CI). The relationships of adverse outcomes in two groups were analyzed. RESULTS: A total of 109 MCDA twin pairs were examined; 15 cases were classified into the abnormal CI group and 94 cases into the normal CI group. The incidence of TTTS was significantly higher in the abnormal than in the normal CI group (26.7% vs 7.45%, P = .04). In patients who developed TTTS, all donors had VCI. CONCLUSION: Ultrasound evaluation of abnormal CI at 11 + 0 to 13 + 6 weeks' gestation in MCDA twins is valuable in the assessment of the risk for TTTS.

Second-Trimester Ultrasound-Measured Umbilical Cord Insertion-to-Placental Edge Distance: Determining an Outcome-Based Threshold for Identifying Marginal Cord Insertions.

OBJECTIVES: We sought to study potential diagnostic criteria for marginal placental cord insertions as determined by associations with obstetric outcomes. METHODS: This single-center retrospective cohort investigation included singleton gestations delivering from January 1, 2012, to December 31, 2016, and having a standard or detailed fetal ultrasound examination from 18 weeks to 21 weeks 6 days. Cord insertion-to-placental edge distances were used to create a referent comparison group and 3 patient groups: greater than 3.0 cm (comparison); greater than 2.0 to 3.0 cm (group 1); greater than 1.0 to 2.0 cm (group 2); and 1.0 cm or less (group 3). The primary outcome consisted of any one of spontaneous delivery before 37 weeks, fetal growth restriction, oligohydramnios, placental abruption, or intrauterine fetal demise. RESULTS: The numbers of participants and mean distances ± SDs for the comparison group and groups 1 to 3, respectively, were 628 and 4.68 ± 1.17 cm, 106 and 2.52 ± 0.26 cm, 131 and 1.60 ± 0.29 cm, and 77 and 0.36 ± 0.37 cm, respectively. The primary outcome was significantly associated only with cord insertion-to-placental edge distances of 1.0 cm or less (adjusted odds ratio, 3.05; 95% confidence interval, 1.73-5.38). CONCLUSIONS: Marginal cord insertions may be diagnosed when the cord insertion-to-placental edge distance is 1.0 cm or less.

Furcate insertion of the umbilical cord: pathological and clinical characteristics in 132 cases.

Objectives Furcate cord insertion is a rare abnormality affecting approximately 0.1% of all pregnancies. Macroscopically, the umbilical vessels separate before reaching the placenta, lose their Wharton's jelly, and insert at the placenta centrally, eccentrically, or marginally. The aim of this retrospective study was to determine the prevalence of furcate cord insertion more accurately, the pathological characteristics, and clinical outcomes. Methods We conducted a retrospective study of 132 cases of furcate insertion of the umbilical cord using the pathological database of the Charité University Hospital Berlin, Germany, between 1993 and 2016. This included 99 cases, including one termination of pregnancy within our institution and 33 cases from external hospitals. An analysis of the pathological features of the 132 cases and the perinatal outcome of the 98 cases within our institution were performed. Results Furcate cord insertion occurred in 0.16% pregnancies. Of the 132 cases, seven cases of intrauterine fetal deaths were observed. Three of those could be linked to the furcate cord insertion. In two of those cases, single umbilical vessel rupture was identified as the cause of fetal death. Conclusions In most cases of furcate cord insertion, the outcome is good; however, intrauterine fetal death occurs in approximately 1.02% of cases.

Assisted reproductive technologies (ART) and placental abnormalities.

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 23 weeks 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±5 y vs. 30.0±5 y; p<0.001), greater preterm birth (29 vs. 6%; p<0.001), and lower BW (2,928±803 g vs. 3,273±586 g; 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 as an 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.

A disadvantage of cesarean section en caul: Umbilical velamentous insertion, a risk factor and proposed mechanism of neonatal anemia.

Cesarean section en caul could cause neonatal anemia, but the mechanism remains unknown. We demonstrate an association between neonatal anemia and velamentous insertion of the umbilical cord in cesarean section en caul, and suggest a way to make this procedure safer. We performed cesarean section en caul, but the placenta and the membrane sac were delivered separately. The neonate was severely anemic. The umbilical cord was attached to the membrane and the blood vessel connecting the umbilical cord and placenta was torn. The amniotic membrane covering the placental surface had peeled away. Velamentous insertion of the umbilical cord could be a cause of neonatal anemia associated with cesarean section en caul.

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

OBJECTIVES: 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. STUDY DESIGN: 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. RESULTS: 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. CONCLUSION: 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.

Modern Ultrasonography of the Umbilical Cord: Prenatal Diagnosis of Umbilical Cord Abnormalities and Assessement of Fetal Wellbeing.

The umbilical cord is the only connection between the mother and the fetus, through which it is possible to transport respiratory gases, nutrients, and metabolites. Thanks to the umbilical cord, the fetus has also the ability to move, which is necessary for its proper psychomotor development. The correct structure and function of umbilical vessels and the entire umbilical cord determine the possibility of proper development and survival of the fetus. Umbilical cord anatomy should be assessed in the ultrasound examination in the first trimester. It is of vital importance to confirm the correct number of umbilical vessels and their intra-abdominal course, as well as carefully assessing the abdominal and placental insertion sites. In the latter half of pregnancy, the use of the Doppler imaging enables assessment of the function of the fetal-placental vessels, thus providing valuable information about the condition of the fetus.

Role of 2-Dimensional Ultrasound Imaging in Placental and Umbilical Cord Morphometry: Literature and Pictorial Review.

Abnormalities of the placenta and umbilical cord have been associated with adverse pregnancy outcomes. Antenatal detection of placental and umbilical cord abnormalities using ultrasound (US) imaging is now gaining popularity with the advancements in obstetric US. This article reviews the use of 2-dimensional obstetric US as a tool to measure and assess placental and umbilical cord morphometry. It highlights the potential role of placental and umbilical cord morphometry as a valuable component of the screening tool for high risk pregnancies and identifies the need for further research to examine its feasibility.

Umbilical Cord Hematoma.

Background: Umbilical cord haematomas may result in mortality or significant morbidity due to interference with vital fetal blood flow. Case report: We present a massive umbilical haematoma in a asymptomatic neonate without risk factors or hypoxic event. Conclusion: Although massive umbilical haematomas may result in miscarriage and fetal hypoxia, in some cases there may be no complications.

Giant umbilical cord and hypoglycemia in an infant with Proteus syndrome.

Proteus syndrome (PS) is characterized by the progressive, segmental, or patchy overgrowth of the skin, and other tissues. This is the first case report of recurrent severe insulin-independent hypoglycemia in an infant with PS. Somatic p.E17K of AKT1 mutation was confirmed. The patient also had a giant umbilical cord, which has not yet been reported in PS.

A poor long-term neurological prognosis is associated with abnormal cord insertion in severe growth-restricted fetuses.

OBJECTIVE: To clarify and compare if the neurological outcomes of fetal growth restriction (FGR) cases with abnormal cord insertion (CI) are associated with a higher risk of a poor neurological outcome in subjects aged 3 years or less versus those with normal CI. METHODS: A multicenter retrospective cohort study was conducted among patients with a birth weight lower than the 3rd percentile, based on the standard reference values for Japanese subjects after 22 weeks' gestation, who were treated at a consortium of nine perinatal centers in Japan between June 2005 and March 2011. Patients whose birth weights were less than the 3rd percentile and whose neurological outcomes from birth to 3 years of age could be checked from their medical records were analyzed. The relationship between abnormal CI and neurological outcomes was analyzed. Univariate and multivariate models of multivariate logistic regression were employed to estimate the raw and odds ratio (OR) with 95% confidence intervals comparing marginal (MCI) and velamentous cord insertion (VCI) to normal CI. RESULTS: Among 365 neonates, 63 cases of MCI and 14 cases of VCI were observed. After excluding 24 cases with neonatal or infant death from the total FGR population, the assessment of the outcomes of the infants aged 3 years or younger showed the following rates of neurological complications: 7.3% (n=25) for cerebral palsy, 8.8% (n=30) for developmental disorders, 16.7% (n=57) for small-for-gestational-age short stature (SGA), 0.6% (n=2) for impaired hearing, 0.9% (n=3) for epilepsy, 1.2% (n=4). The ORs (95% confidence intervals) based on multivariate analysis were as follows: cerebral palsy=10.1 (2.4-41.5) in the VCI group and 4.3 (1.6-11.9) in the MCI group, developmental disorders=6.7 (1.7-26) in the VCI group and 3.9 (1.1-14.2) in the single umbilical artery (SUA) group, 5.1 (1.4-18.7) for birth weight <1000 g and 2.8 (1.2-6.7) for placental weight <200 g. CONCLUSIONS: The present results indicate that growth-restricted fetuses diagnosed with a birth weight below the 3rd percentile exhibiting abnormal umbilical CI are at a high risk for poor neurological outcomes, including cerebral palsy and/or developmental disorders.

Roles of venovenous anastomosis and umbilical cord insertion abnormalities in birthweight discordance in monochorionic-diamniotic twin pregnancies without twin-twin transfusion syndrome.

AIM: We evaluated risk factors for birthweight discordance in monochorionic diamniotic (MCDA) twin pregnancies without twin-twin transfusion syndrome (TTTS). METHODS: We investigated all MCDA twin placentas injected with colored dye at our institution between 2007 and 2015. We excluded pairs of twins with TTTS, fetal demise, or severe fetal malformation. All pairs of twins were assigned to the discordant group (birthweight discordance ≥ 25%) or the concordant group (birthweight discordance < 25%). In each pair of twins, we described vascular anastomoses as either arterioarterial, venovenous (VV), or arterial-venous, and abnormal umbilical cord insertion as either marginal or velamentous. We also recorded placental sharing discordance. RESULTS: A total of 150 placentas were analyzed. The incidence of VV anastomosis in the discordant group (40%) was significantly higher than that in the concordant group (12%, P = 0.005). Unilateral abnormal umbilical cord insertion was significantly more common in the discordant group (85%) than in the concordant group (38%, P < 0.001). Placental sharing discordance was seen more frequently in the discordant group than in the concordant group. Multiple logistic analysis revealed that VV anastomosis (odds ratio: 4.7; 95% confidence interval: 1.2-18.6, P < 0.01) and unilateral abnormal umbilical cord insertion of the smaller twin (odds ratio: 5.7; 95% confidence interval: 1.4-22.9, P < 0.01) were independent risk factors for birthweight discordance. CONCLUSION: VV anastomoses and unilateral abnormal umbilical cord insertion of the smaller twin are independent risk factors for birthweight discordance in MCDA twin pregnancies without TTTS.