Abnormal placental cord insertion and adverse pregnancy outcomes: a systematic review and meta-analysis

Maternal background and perinatal complications in MCI: A retrospective cohort study

OBJECTIVE

Marginal cord insertion (MCI) is often defined as an abnormal placental cord insertion (PCI), yet there is limited discussion on the maternal backgrounds and perinatal complications associated with its occurrence. This retrospective cohort study aimed to investigate maternal backgrounds associated with MCI and to compare perinatal outcomes between MCI and normal PCI.

MATERIALS AND METHODS

The study included 1038 deliveries from 2021 to 2023 in our institution, examining maternal backgrounds and perinatal outcomes. Multivariable logistic regression analysis was conducted for variables that showed significance in univariate analysis of maternal backgrounds. For perinatal outcomes, variables that exhibited significance were further analyzed using multivariable logistic regression, considering factors previously reported to be associated with those events.

RESULTS

9.5 % exhibited MCI. Assisted reproductive technology, nulliparous, and congenital uterine anomalies were identified as independent risk factors for MCI. In perinatal outcomes, fetal growth restriction (FGR) and emergency cesarean section were significantly more prevalent in cases with MCI. Even when compared to factors previously reported to be associated with FGR and emergency cesarean section, MCI remained an independent risk factor.

CONCLUSION

In addition to previously reported factors such as ART and primiparity, uterine anomalies were also identified as risk factors for MCI. It is important to manage MCI with the awareness that it increases the incidence of perinatal complications.

Congenital Heart Disease Fetuses Have Decreased Mid-Gestational Placental Flow, Placental Malperfusion Defects, and Impaired Growth

Background

Placental health may impact the development and outcomes of congenital heart disease (CHD). CHD fetuses have been shown retrospectively to have decreased placental blood flow.

Objectives

The purpose of this study was to determine if CHD fetuses with decreased placental blood flow have placental pathology at birth and if there is a relationship between placental blood flow, placental pathology, and outcomes.

Methods

We performed a prospective case-control study of 38 CHD fetuses, including 28 with single ventricle physiology and 36 controls. Demographic, clinical, and postnatal biometric data were collected. Umbilical venous volume flow (UVVF) was measured from 2nd trimester fetal echocardiograms. Placentas underwent standardized pathological analysis. Standard descriptive statistics and regression analyses were performed to analyze the relationship between UVVF, placental defects, and outcomes.

Results

CHD fetuses had a 15% decrease in mid-gestational UVVF indexed to fetal weight (P < 0.01), and a 27% reduction in UVVF as a proportion of fetal cardiac output (P < 0.01) compared to controls. CHD fetuses had increased placental maternal vascular malperfusion (MVM) lesions (44% vs 18%, P < 0.05), especially high-grade MVM (39% vs 9.1%, P = 0.05), and a trend toward increased placental fetal vascular malperfusion lesions (42% vs 23%, P = 0.10). Placental MVM but not fetal vascular malperfusion lesions were associated with decreased birth weight in CHD fetuses (P < 0.001). There was no association between UVVF and placental pathologic findings or fetal growth.

Conclusions

CHD (particularly single ventricle) fetuses have decreased mid-gestational placental blood flow, increased placental malperfusion defects, and impaired fetal growth. Placental MVM may influence impaired fetal growth in CHD.

Effect of abnormal placental cord insertion on hemodynamic change of umbilical cord in a tertiary center: a prospective cohort study

BACKGROUND

Our study aims to evaluate the umbilical vein (UV) hemodynamic change in the prenatal cohort of pregnancies diagnosed with abnormal placental cord insertion (aPCI).

METHODS

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.

RESULTS

Among 570 singleton fetuses between 18 + 0 and 40 + 6 weeks 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 145.39 ml/min, 146.18 ml/min, and 93.96 ml/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 ± 527 g vs. 3144 ± 577 g, P < 0.05), delivery at an earlier gestational age (38.0 ± 1.55 weeks vs. 38.8 ± 2.34 weeks, P < 0.05), higher bicarbonate (25.08 ± 1.72 mmol/L vs. 22.66 ± 4.05 mmol/L, P < 0.05), and higher standard base excess (-1.14 ± 1.50 mmol/L vs. -3.30 ± 3.22 mmol/L, P < 0.05) were found in the VCI group.

CONCLUSIONS

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.

Association of congenital uterine anomaly with abnormal placental cord insertion and adverse pregnancy complications: a retrospective cohort study

OBJECTIVE

Congenital uterine anomalies during pregnancy increase the risk of pregnancy complications such as miscarriage, preterm delivery, fetal malpresentation, cesarean delivery, and fetal growth restriction. However, few studies have examined uterine anomalies in relation to perinatal complications other than those mentioned above. We investigated the association between pregnancies complicated by congenital uterine anomalies and various perinatal outcomes at our institution.

METHODS

This retrospective cohort study was conducted from January 2009 to May 2021. We included cases of uterine anomalies, such as septate, bicornuate, unicornuate, and didelphic uterus. First, the perinatal complications and neonatal outcomes were compared between pregnancies complicated by uterine anomalies and those with normal uteri. Second, we conducted an analysis based on the type of uterine anomalies classified into two groups: the minor anomaly group consisted of anomalies limited to the uterine cavity, such as the septate uterus, whereas the major anomaly group included anomalies affecting the uterine shape, such as bicornuate, unicornuate, and didelphic uterus. We compared the incidence of perinatal complications among the major anomaly, minor anomaly, and normal uterus groups.

RESULTS

During the study period, 45 pregnancies were complicated with uterine anomalies. The minor anomaly group included 11 patients and the major anomaly group included 34 patients. The incidence of fetal malpresentation was significantly higher in the uterine anomaly group than in the normal uterus group (18% vs. 3.7%, p = .04). Furthermore, the frequency of abnormal placental cord insertion was significantly higher in the uterine anomaly group (16% vs. 3.7%, p = .01). Examination based on the type of uterine anomaly revealed significant differences in cervical incompetence, malpresentation, cesarean section, and abnormal placental cord insertion. Cervical incompetence was more likely in patients with minor anomalies. In contrast, fetal malpresentation, cesarean section, and abnormal placental cord insertion were more likely in the major anomaly group.

CONCLUSIONS

In addition to the findings reported in previous studies, abnormal placental cord insertion was more frequent in pregnancies complicated by uterine anomalies.

Perinatal and obstetric-neonatal outcomes following frozen embryo transfer cycles with a thinner endometrium: a retrospective study

OBJECTIVE

The purpose of this study was to evaluate the relationship of thin endometrial thickness (EMT) on the maternal and child health outcome of frozen-thawed embryo transfer (FET) cycles with singletons.

METHODS

The retrospective cohort study included 1,771 live singleton deliveries, with 273 in the thin endometrium group (EMT ≤ 7.5 mm) and 1,498 in the control group (EMT > 7.5 mm). Pregnancy, perinatal complications and neonatal outcomes were compared between the two groups.

RESULTS

Women in the thinner endometrium group had higher rates of preeclampsia (7.69% vs. 7.00%), placenta previa (4.39% vs. 2.43%), postpartum haemorrhage (15.38% vs. 11.42%) than the control groups, although they were not significantly different. Significant difference was observed in the rates of placental abruption (1.09% vs. 0.07%, P = 0.001), abnormal placental cord insertion (3.66% vs. 1.74%, P = 0.011), placental adherence (15.38% vs. 7.14%, P < 0.001) between the two groups. No significant difference could be found regarding preterm labour, macrosomia, Apgar ≤ 7, large for gestational age (LGA) and appropriate for gestational age (AGA), and singletons from the thinner endometrium group had a significantly lower birthweight than those from the controls. Then after adjusting for confounders, thinner endometrium was still statistically significantly associated with placental adherence, postpartum haemorrhage and low birthweight (LBW).

CONCLUSION

These findings highlight the important role of endometrial thickness in influencing perinatal and obstetric-neonatal outcomes in FET cycles. The study contributes to the growing body of evidence supporting the clinical relevance of endometrial thickness in FET cycles and underscores the need for close monitoring and management of pregnancies in women with a thin endometrium. Future research should focus on elucidating the underlying mechanisms and identifying effective interventions to improve endometrial thickness and pregnancy outcomes in this patient population.

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

Introduction/Purpose

It 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.

Methods

Eighty-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.

Results

The 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.

Conclusions

Placental 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.

Prevalence, Risk Factors, and Perinatal Outcomes of Velamentous Umbilical Cord Insertion in Twin Pregnancies: A Single-Center Retrospective Study

BACKGROUND

The effect of velamentous cord insertion (VCI) on perinatal outcomes in twin pregnancies is unclear due to conflicting findings. This retrospective study aimed to examine VCI prevalence and related risk factors in twin pregnancies and its association with adverse perinatal outcomes.

METHODS

Women with twin pregnancies who delivered between January 2012 and December 2021 in a single tertiary hospital were included. The participants were divided into dichorionic (DC) and monochorionic diamniotic (MCDA) groups, and their maternal and fetal characteristics and VCI rates were compared. Logistic regression models were used to identify risk factors for VCI and VCI-related perinatal outcomes.

RESULTS

Among the 694 twin pregnancies included in this study, the VCI rate was significantly higher in MCDA than in DC twins. Body mass index and MCDA twins were significant risk factors for VCI, whereas assisted reproductive technology pregnancy was a significant protective factor against VCI. In DC twins, VCI did not affect perinatal outcomes. In MCDA twins, VCI was a significant risk factor for fetal growth restriction, twin-to-twin transfusion syndrome, and preterm birth at <36 weeks.

CONCLUSIONS

VCI was a prominent risk factor for adverse perinatal outcomes only in MCDA twins. Antenatal sonographic assessment of the umbilical cord insertion site would be beneficial.

Relationship Between Anatomic Features of the Placenta, the Type of Abnormal Placental Cord Insertion and Adverse Pregnancy Outcomes in Singleton Pregnancies: A Prospective Observational Study

INTRODUCTION

This study aimed to evaluate the potential value of placental anatomic features and various types of normal and abnormal cord insertion types in predicting adverse maternal-fetal outcomes in singleton pregnancies. We also tried to assess the association between these outcomes and various types of placental cord insertion.

METHOD

This prospective observational study was performed on singleton pregnancies. For each patient placental features including diameter, thickness, type of cord insertion, and the shortest distance between the cord insertion point and placental edge were recorded. The relationship between these factors and the development of multiple adverse pregnancy outcomes including preterm labor, intrauterine fetal death (IUFD), and the rate of neonatal intensive care unit (NICU) admissions were evaluated and reported.

RESULTS

Overall 308 patients were enrolled in the study. Smoker mothers had significantly smaller placentas (P-value = .008), and those with lower diameter placentas were more likely to suffer from IUFD (P-value = .0001). Shorter placental cord insertion distances led to more episodes of preterm labor (P-value = .057). Eccentric-type placental cord insertion was significantly associated with the development of preeclampsia (P-value = .006).

DISCUSSION

Abnormalities in placental diameter and cord insertion can lead to significant maternal-fetal complications including preterm labor, IUFD, and preeclampsia.

Associations between velamentous or marginal cord insertion and risk of adverse perinatal outcomes in twin pregnancies: a retrospective cohort study

BACKGROUND

Velamentous cord insertion (VCI) and marginal cord insertion (MCI) are well-known risk factors for adverse perinatal outcomes in singleton pregnancies. However, the potential links between VCI or MCI and perinatal outcomes in twin pregnancies have yet to be systematically evaluated. This study aimed to investigate the relationships between VCI or MCI and perinatal outcomes in twin pregnancies.

METHODS

This retrospective single-center cohort study included women with twin pregnancies who gave birth in a tertiary hospital in Southwest, China between January 2017 and December 2022. VCI and MCI were identified by abdominal ultrasound and confirmed after placental delivery. Logistic regression, multinomial logit regression and generalized estimation equation models were used to evaluate the association between VCI or MCI and perinatal outcomes.

RESULTS

A total of 3682 twin pregnancies were included, including 100 (2.7%) pregnancies with VCI and 149 (4.0%) pregnancies with MCI. Compared to pregnancies with normal cord insertion, both monochorionic and dichorionic pregnancies with VCI were associated with an increased risk of preterm delivery 32-34 weeks (aRRR 2.94, 95% CI 1.03-8.39; aRRR 2.55, 95% CI 1.19-5.46, respectively), while pregnancies with MCI were not associated with preterm delivery. VCI was associated with a higher incidence of placental previa (aOR 6.36, 95% CI 1.92-21.04) in monochorionic pregnancies and placental accreta (aOR 1.85, 95% CI 1.06-3.23) in dichorionic pregnancies. MCI was associated with an increased risk of preeclampsia (aOR 3.07, 95% CI 1.49-6.32), intertwin birthweight discordance ≥ 20% (aOR 2.40, 95% CI 1.08-5.60) and selective fetal growth restriction (aOR 2.46, 95% CI 1.08-5.60) in monochorionic pregnancies and small-for-gestational age neonates (aOR 1.97, 95% CI 1.24-3.14) in dichorionic pregnancies.

CONCLUSIONS

VCI was associated with an increased risk of preterm delivery in twin pregnancies irrespective of chorionicity, whereas MCI was associated with an increased preeclampsia risk, significant intertwin birthweight discordance in monochorionic pregnancies and small-for-gestational age neonates in dichorionic pregnancies.

The Placenta in Congenital Heart Disease: Form, Function and Outcomes

The maternal-fetal environment, controlled and modulated by the placenta, plays a critical role in the development and well-being of the fetus, with long-term impact through programming of lifelong health. The fetal cardiovascular system and placenta emerge at the same time embryologically, and thus placental form and function are altered in the presence of congenital heart disease (CHD). In this review, we report on what is known about the placenta from a structural and functional perspective when there is CHD. We describe the various unique pathologic findings as well as the diagnostic imaging tools used to characterize placental function in utero. With growing interest in the placenta, a standardized approach to characterizing placental pathology has emerged. Furthermore, application of ultrasonography techniques and magnetic resonance imaging now allow for insights into placental blood flow and functionality in vivo. An improved understanding of the intriguing relationship between the placenta and the fetal cardiovascular system will provide opportunities to develop novel ways to optimize outcomes. Once better understood, therapeutic modulation of placental function offered during the vulnerable period of fetal plasticity may be one of the most impactful ways to alter the course of CHD and its complications.

Peripheral cord insertion is associated with adverse pregnancy outcome only when accompanied by clinically significant placental pathology

OBJECTIVE

To examine the relationship between umbilical cord insertion site, placental pathology and adverse pregnancy outcome in a cohort of normal and complicated pregnancies.

METHODS

Sonographic measurement of the cord insertion and detailed placental pathology were performed in 309 participants. Associations between cord insertion site, placental pathology and adverse pregnancy outcome (pre-eclampsia, preterm birth, small-for-gestational age) were examined.

RESULTS

A total of 93 (30%) participants were identified by pathological examination to have a peripheral cord insertion site. Only 41 of the 93 (44%) peripheral cords were detected by prenatal ultrasound. Peripherally inserted cords were associated significantly (P < 0.0001) with diagnostic placental pathology (most commonly with maternal vascular malperfusion (MVM)); of which 85% had an adverse pregnancy outcome. In cases of isolated peripheral cords, without placental pathology, the incidence of adverse outcome was not statistically different when compared to those with central cord insertion and no placental pathology (31% vs 18%; P = 0.3). A peripheral cord with an abnormal umbilical artery (UA) pulsatility index (PI) corresponded to an adverse outcome in 96% of cases compared to 29% when the UA-PI was normal.

CONCLUSIONS

This study demonstrates that peripheral cord insertion is often part of the spectrum of findings of MVM disease and is associated with adverse pregnancy outcome. However, adverse outcome was uncommon when there was an isolated peripheral cord insertion and no placental pathology. Therefore, additional sonographic and biochemical features of MVM should be sought when a peripheral cord is observed. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

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

Introduction

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.

Methods

Members of the Australian Sonographer Accreditation Registry were invited to participate in an online survey which was distributed between February and March 2022.

Results

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.

Conclusions

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.

Machine learning-based placental clusters and their associations with adverse pregnancy outcomes

BACKGROUND

Placental abnormalities have been described in clinical convenience samples, with predominately adverse outcomes. Few studies have described placental patterns in unselected samples.

OBJECTIVE

We aimed to investigate associations between co-occurring placental features and adverse pregnancy outcomes in a prospective cohort of singletons.

METHODS

Data were from the Safe Passage study (U.S. and South Africa, 2007-2015). Before 24 weeks' gestation, participants were randomly invited to donate placental tissue at delivery for blinded, standardised pathological examination. We used hierarchical clustering to construct statistically derived groups using 60 placental features. We estimated associations between the placental clusters and select adverse pregnancy outcomes, expressed as unadjusted and adjusted risk ratios (RRs) and robust 95% confidence intervals (CI).

RESULTS

We selected a 7-cluster model. After collapsing 2 clusters to form the reference group, we labelled the resulting 6 analytic clusters according to the overarching category of their most predominant feature(s): severe maternal vascular malperfusion (n = 117), fetal vascular malperfusion (n = 222), other vascular malperfusion (n = 516), inflammation 1 (n = 269), inflammation 2 (n = 175), and normal (n = 706). Risks for all outcomes were elevated in the severe maternal vascular malperfusion cluster. For instance, in unadjusted analyses, this cluster had 12 times the risk of stillbirth (RR 12.07, 95% CI 4.20, 34.68) and an almost doubling in the risk of preterm delivery (RR 1.93, 95% CI 1.27, 2.93) compared with the normal cluster. Small infant size was more common among the abnormal clusters, with the highest unadjusted RRs observed in the fetal vascular malperfusion cluster (small for gestational age birth RR 2.99, 95% CI 2.24, 3.98, head circumference <10th percentile RR 2.86, 95% CI 1.60, 5.12). Upon adjustment for known risk factors, most RRs attenuated but remained >1.

CONCLUSION

Our study adds to the growing body of epidemiologic research, finding adverse pregnancy outcomes may occur through etiologic mechanisms involving co-occurring placental abnormalities.

Impact of velamentous cord insertion on perinatal outcomes: a systematic review and meta-analysis

OBJECTIVE

Velamentous cord insertion may be identified prenatally, but the clinical implications of this diagnosis remain controversial. This meta-analysis aimed to quantitatively summarize current data on the association of velamentous cord insertion and adverse perinatal outcomes.

DATA SOURCES

A systematic search was performed in MEDLINE, Scopus, and the Cochrane Library from inception until May 22, 2022 to identify eligible studies.

STUDY ELIGIBILITY CRITERIA

Observational studies including singleton pregnancies with velamentous cord insertion, either prenatally or postnatally identified, and comparing them with those with central/eccentric cord insertion were considered eligible.

METHODS

The quality of the studies was assessed with the Newcastle-Ottawa scale and the risk of bias with the Quality In Prognosis Studies (QUIPS) tool. The main outcome was small-for-gestational-age neonates. Heterogeneity of the studies was evaluated using a Q test and an I² index. Analyses were performed using a random-effects model, with outcome data reported as relative risk or mean difference with 95% confidence interval.

RESULTS

In total, 9 cohort and 2 case-control studies, of which 4 had prenatal and 7 had postnatal velamentous cord insertion diagnosis, were included. The overall prevalence of velamentous cord insertion was estimated to be 1.4% among singleton pregnancies. Compared with the central/eccentric cord insertion control group, pregnancies with velamentous cord insertion were at higher risk of several adverse perinatal outcomes, namely small-for-gestational-age neonates (relative risk, 1.93; 95% confidence interval, 1.54-2.41), preeclampsia (relative risk, 1.85; 95% confidence interval, 1.01-3.39), pregnancy-induced hypertension (relative risk, 1.58; 95% confidence interval, 1.46-1.70), stillbirth (relative risk, 4.12; 95% confidence interval, 1.92-8.87), placental abruption (relative risk, 2.94; 95% confidence interval, 1.72-5.03), preterm delivery (relative risk, 2.14; 95% confidence interval, 1.73-2.65), emergency cesarean delivery (relative risk, 2.03; 95% confidence interval, 1.22-3.38), 1-minute Apgar score <7 (relative risk, 1.53; 95% confidence interval, 1.14-2.05), 5-minute Apgar score <7 (relative risk, 1.97; 95% confidence interval, 1.43-2.71), and neonatal intensive care unit admission (relative risk, 1.63; 95% confidence interval, 1.32-2.02). In a subgroup analysis, prenatally diagnosed velamentous cord insertion was associated with small-for-gestational-age neonates (relative risk, 1.66; 95% confidence interval, 1.19-2.32), stillbirth (relative risk, 4.78; 95% confidence interval, 1.42-16.08), and preterm delivery (relative risk, 2.69; 95% confidence interval, 2.01-3.60). In a sensitivity analysis of studies excluding cases with vasa previa, velamentous cord insertion was associated with an increased risk of small-for-gestational-age neonates (relative risk, 2.69; 95% confidence interval, 1.73-4.17), pregnancy-induced hypertension (relative risk, 1.94; 95% confidence interval, 1.24-3.01), and stillbirth (relative risk, 9.42; 95% confidence interval, 3.19-27.76), but not preterm delivery (relative risk, 1.92; 95% confidence interval, 0.82-4.54).

CONCLUSION

Velamentous cord insertion is associated with several adverse perinatal outcomes, including stillbirth, and these associations persist when only prenatally diagnosed cases are considered and when vasa previa cases are excluded. According to these findings, the exact pathophysiology should be further investigated and an effective prenatal monitoring plan should be developed.

Feto-placental Unit: From Development to Function

The placenta is an intriguing organ that allows us to survive intrauterine life. This essential organ connects both mother and fetus and plays a crucial role in maternal and fetal well-being. This chapter presents an overview of the morphological and functional aspects of human placental development. First, we describe early human placental development and the characterization of the cell types found in the human placenta. Second, the human placenta from the second trimester to the term of gestation is reviewed, focusing on the morphology and specific pathologies that affect the placenta. Finally, we focus on the placenta's primary functions, such as oxygen and nutrient transport, and their importance for placental development.

Obstetric Outcomes in Singleton Pregnancies with Abnormal Placental Cord Insertions

OBJECTIVE

There is wide variation in the management of pregnancies complicated by abnormal placental cord insertion (PCI), which includes velamentous cord insertion (VCI) and marginal cord insertion (MCI). We tested the hypothesis that abnormal PCI is associated with small for gestational age (SGA) infants.

STUDY DESIGN

This is a retrospective cohort study of all pregnant patients undergoing anatomic ultrasound at a single institution from 2010 to 2017. Patients with abnormal PCI were matched in a 1:2 ratio by race, parity, gestational age at the time of ultrasound, and obesity to patients with normal PCIs. The primary outcome was SGA at delivery. Secondary outcomes were cesarean delivery, preterm delivery, cesarean delivery for nonreassuring fetal status, 5-minute Apgar score < 7, umbilical artery pH < 7.1, and neonatal intensive care unit admission. These outcomes were compared using univariate and bivariate analyses.

RESULTS

Abnormal PCI was associated with an increased risk of SGA (relative risk [RR]: 2.43; 95% confidence interval [CI]: 1.26-4.69), increased risk of preterm delivery <37 weeks (RR: 3.60; 95% CI: 1.74-7.46), and <34 weeks (RR: 3.50; 95% CI: 1.05-11.63) compared with patients with normal PCI. There was no difference in rates of cesarean delivery, Apgar score of <7 at 5 minutes, acidemia, or neonatal intensive care unit admission between normal and abnormal PCI groups. In a stratified analysis, the association between abnormal PCI and SGA did not differ by the type of abnormal PCI (p for interaction = 0.46).

CONCLUSION

Abnormal PCI is associated with an increased risk of SGA and preterm delivery. These results suggest that serial fetal growth assessments in this population may be warranted.

KEY POINTS

· Abnormal PCI is associated with SGA infants and preterm birth.. · If an abnormal PCI is identified, the provider should consider serial growth ultrasounds.. · There is no difference in obstetric outcomes between VCI and MCI..

Pre-eclampsia in a Sub-Saharan African country and maternal-perinatal outcome

Our comparative cohort study, carried out between 3^rd January and 30^th April 2020, looked at the maternal and perinatal outcomes associated with pre-eclampsia. Of 2019 booked pregnant women, 141 (7.0%) had pre-eclampsia, and 59.8% of these were severe at admission. Significant adverse maternal outcomes were eclampsia, HELLP (haemolysis, elevated liver enzymes, and low platelets) syndrome, and placental abruption, and significant adverse perinatal outcomes were intra-uterine fetal death, preterm delivery, low birth weight (LBW), neonatal asphyxia and early neonatal death. Close attention needs to be given to women with pre-eclampsia in poor resource circumstances.

The impact of ultrasound-based antenatal screening strategies to detect vasa praevia in the United Kingdom: An exploratory study using decision analytic modelling methods

The objective of this exploratory modelling study was to estimate the effects of second-trimester, ultrasound-based antenatal detection strategies for vasa praevia (VP) in a hypothetical cohort of pregnant women. For this, a decision-analytic tree model was developed covering four discrete detection pathways/strategies: no screening; screening targeted at women undergoing in-vitro fertilisation (IVF); screening targeted at women with low-lying placentas (LLP); screening targeted at women with velamentous cord insertion (VCI) or a bilobed or succenturiate (BL/S) placenta. Main outcome measures were the number of referrals to transvaginal sonography (TVS), diagnosed and undiagnosed cases of VP, overdetected cases of VCI, and VP-associated perinatal mortality. The greatest number of referrals to TVS occurred in the LLP-based (2,083) and VCI-based screening (1,319) pathways. These two pathways also led to the highest proportions of pregnancies diagnosed with VP (VCI-based screening: 552 [78.9% of all pregnancies]; LLP-based: 371 [53.5%]) and the lowest proportions of VP leading to perinatal death (VCI-based screening: 100 [14.2%]; LLP-based: 196 [28.0%]). In contrast, the IVF-based pathway resulted in 66 TVS referrals, 50 VP diagnoses (7.1% of all VP pregnancies), and 368 (52.6%) VP-associated perinatal deaths which was comparable to the no screening pathway (380 [54.3%]). The VCI-based pathway resulted in the greatest detection of VCI (14,238 [99.1%]), followed by the IVF-based pathway (443 [3.1%]); no VCI detection occurred in the LLP-based or no screening pathways. In conclusion, the model results suggest that a targeted LLP-based approach could detect a substantial proportion of VP cases, while avoiding VCI overdetection and requiring minimal changes to current clinical practice. High-quality data is required to explore the clinical and cost-effectiveness of this and other detection strategies further. This is necessary to provide a robust basis for future discussion about routine screening for VP.

The Characteristics and Obstetric Outcomes of Type II Vasa Previa: Systematic Review and Meta-Analysis

Vasa previa is a rare fetal life-threatening obstetric disease classified into types I and II. This study aimed to examine the characteristics and obstetric outcomes of type II vasa previa. A systematic review was performed, and 20 studies (1998-2022) were identified. The results from six studies showed that type II vasa previa accounted for 21.3% of vasa previa cases. The characteristics and obstetric outcomes (rate of assisted reproductive technology (ART), antenatal diagnosis, emergent cesarean delivery, maternal transfusion, gestational age at delivery, and neonatal mortality) were compared between type I and II vasa previa, and all outcomes of interest were similar. The association between ART and abnormal placenta (bilobed placenta or succenturiate lobe) was examined in three studies, and the results were as follows: (i) increased rate of succenturiate lobes (ART versus non-ART pregnancy; OR (odds ratio) 6.97, 95% confidence interval (CI) 2.45-19.78); (ii) similar rate of abnormal placenta (cleavage-stage versus blastocyst embryo transfer); (iii) increased rate of abnormal placenta (frozen versus fresh embryo transfer; OR 2.97, 95%CI 1.10-7.96). Although the outcomes of type II vasa previa appear to be similar to those of type I vasa previa, the current evidence is insufficient for a robust conclusion.

Impact of Marginal and Velamentous Cord Insertion on Uterine Artery Doppler Indices, Fetal Growth, and Preeclampsia

OBJECTIVES

To assess the impact of marginal (MCI) or velamentous (VCI) cord insertion on uterine artery pulsatility index (UtA PI), preeclampsia (PE), and offspring's birthweight (BW).

METHODS

A retrospective cohort study of singleton pregnancies, undergoing routine anomaly scan at 20⁺⁰ -23⁺⁶ gestational weeks, was conducted between 2016 and 2020. The effect of placental cord insertion on BW and UtA mean PI z-scores was assessed using the t test or analysis of variance and post-hoc tests; their association with PE was evaluated with the chi-square test. A multivariate logistic regression model was employed to assess the independent association of placental cord insertion and UtA PI z-score with PE, BW <10th, <5th centile, and intrauterine death (IUD), using specific confounders.

RESULTS

The study population included 4453 pregnancies. Conception via assisted reproductive technology (ART) was associated with increased risk of abnormal cord insertion (odds ratio [OR]: 2.237; 95% confidence interval [CI]: 1.561-3.206; P < .001). Women with MCI/VCI had higher mean UtA PI z-score than those with central/eccentric (0.29 vs 0.01; mean difference: -0.28; 95% CI: -0.399 to -0.165; P < .001). MCI/VCI were associated with higher rates of BW <10th centile (central/eccentric: 16.2% vs MCI: 21.9% vs VCI: 35.7%; P < .001) and BW <5th centile (9.8 vs 15.1 vs 23.2%, respectively; P < .001). No association was identified between MCI/VCI and PE (P = .968). Finally, VCI (aOR: 13.717; 95% CI: 1.576-119.379; P = .018) and increased BMI (aOR: 1.167; 95% CI: 1.071-1.271; P < .001) significantly correlated with IUD.

CONCLUSIONS

Abnormal cord insertion is more common in ART pregnancies. MCI/VCI are associated with higher mean UtA PI and lower BW centile, but not with increased risk of PE.

Assisted Reproductive Technique and Abnormal Cord Insertion: A Systematic Review and Meta-Analysis

Abnormal cord insertion (ACI) is associated with adverse obstetric outcomes; however, the relationship between ACI and assisted reproductive technology (ART) has not been examined in a meta-analysis. This study examines the association between ACI and ART, and delivery outcomes of women with ACI. A systematic review was conducted, and 16 studies (1990–2021) met the inclusion criteria. In the unadjusted pooled analysis (n = 10), ART was correlated with a higher rate of velamentous cord insertion (VCI) (odds ratio (OR) 2.14, 95% confidence interval (CI) 1.64–2.79), marginal cord insertion (n = 6; OR 1.58, 95%CI 1.26–1.99), and vasa previa (n = 1; OR 10.96, 95%CI 2.94–40.89). Nevertheless, the VCI rate was similar among the different ART types (blastocyst versus cleavage-stage transfer and frozen versus fresh embryo transfer). Regarding the cesarean delivery (CD) rate, women with VCI were more likely to have elective (n = 3; OR 1.13, 95%CI 1.04–1.22) and emergent CD (n = 5; OR 1.93, 95%CI 1.82–2.03). In conclusion, ART may be correlated with an increased prevalence of ACI. However, most studies could not exclude confounding factors; thus, further studies are warranted to characterize ART as a risk factor for ACI. In women with ACI, elective and emergent CD rates are high.

Abnormal placental cord insertion, hypertensive disorders of pregnancy and birth length may be involved in development of hypospadias in male fetuses

Objectives

Hypospadias is a congenital disease characterized by morphological abnormalities of the penis, including abnormal urethral opening and penile flexion, which cause urination disorders and/or sexual intercourse difficulty. Various factors have been suggested to cause this anomaly, but evidence concerning risk factors causing this anomaly is insufficient. We evaluated the etiology of hypospadias in Japan using the Common Database of the National Hospitals' Neonatal study group.

Study design

We retrospectively evaluated 7,865 male neonates registered in the NICU Common Database of the National Hospitals' Neonatal study group. The subjects were divided into two groups by the presence (n = 43) or absence (n = 7,822) of hypospadias. Statistical analyses were performed to compare nominal variables between the groups by Fisher's direct establishment calculation method and logistic regression analyses.

Results

A univariate analysis showed significant between‐group differences in hypertensive disorders in pregnancy (odds ratio [OR]: 4.02, 95% confidence interval [CI]: 1.95–7.90), placental weight <−1.28 standard deviation (SD; OR: 5.06, 95% CI: 2.45–10.32), abnormal placental cord insertion (OR: 4.7, 95% CI: 2.62–9.76), birth length <−2SD (OR: 10.56, 95% CI: 5.00–21.1) and birth weight <−2SD (OR: 8.17, 95% CI: 4.17–15.68). A multivariate analysis showed a significant between‐group difference in hypertensive disorders of pregnancy (adjusted OR [AOR]: 2.30, 95% CI: 1.09–4.85), abnormal placental cord insertion (AOR: 3.69, 95% CI: 1.83–7.44) and birth length <−2SD (AOR: 3.44, 95% CI: 1.26–9.42).

Conclusion

Abnormal placental cord insertion, hypertensive disorders of pregnancy and birth length may be involved in hypospadias development in male neonates in conjunction with placental dysfunction in early pregnancy.

Clinically Relevant Prenatal Ultrasound Diagnosis of Umbilical Cord Pathology

Umbilical cord abnormalities are not rare, and are often associated with structural or chromosomal abnormalities, fetal intrauterine growth restriction, and poor pregnancy outcomes; the latter can be a result of prematurity, placentation deficiency or, implicitly, an increased index of cesarean delivery due to the presence of fetal distress, higher admission to neonatal intensive care, and increased prenatal mortality rates. Even if the incidence of velamentous insertion, vasa praevia and umbilical knots is low, these pathologies increase the fetal morbidity and mortality prenatally and intrapartum. There is a vast heterogeneity among societies’ guidelines regarding the umbilical cord examination. We consider the mandatory introduction of placental cord insertion examination in the first and second trimester to practice guidelines for fetal ultrasound scans. Moreover, during the mid-trimester scan, we recommend a transvaginal ultrasound and color Doppler assessment of the internal cervical os for low-lying placentas, marginal or velamentous cord insertion, and the evaluation of umbilical cord entanglement between the insertion sites whenever it is incidentally found. Based on the pathological description and the neonatal outcome reported for each entity, we conclude our descriptive review by establishing a new, clinically relevant classification of these umbilical cord anomalies.

Ex-Vivo MRI of the Normal Human Placenta: Structural-Functional Interplay and the Association With Birth Weight

BACKGROUND

Advanced magnetic resonance imaging (MRI) methods are increasingly being used to assess the human placenta. Yet, the structure-function interplay in normal placentas and their associations with pregnancy risks are not fully understood.

PURPOSE

To characterize the normal human placental structure (volume and umbilical cord centricity index (CI)) and function (perfusion) ex-vivo using MRI, to assess their association with birth weight (BW), and identify imaging-markers for placentas at risk for dysfunction.

STUDY TYPE

Prospective.

POPULATION

Twenty normal term ex-vivo placentas.

FIELD STRENGTH/SEQUENCE

3 T/ T₁ and T₂ weighted (T₁ W, T₂ W) turbo spin-echo, three-dimensional susceptibility-weighted image, and time-resolved angiography with interleaved stochastic trajectories (TWIST), during passage of a contrast agent using MRI compatible perfusion system that mimics placental flow.

ASSESSMENT

Placental volume and CI were manually extracted from the T₁ W images by a fetal-placental MRI scientist (D.L., 7 years of experience). Perfusion maps including bolus arrival-time and full-width at half maximum were calculated from the TWIST data. Mean values, entropy, and asymmetries were calculated from each perfusion map, relating to both the whole placenta and volumes of interest (VOIs) within the umbilical cord and its daughter blood vessels.

STATISTICAL TESTS

Pearson correlations with correction for multiple comparisons using false discovery rate were performed between structural and functional parameters, and with BW, with P < 0.05 considered significant.

RESULTS

All placentas were successfully perfused and scanned. Significant correlations were found between whole placenta and VOIs perfusion parameters (mean R = 0.76 ± 0.06, range = 0.67-0.89), which were also significantly correlated with CI (mean R = 0.72 ± 0.05, range = 0.65-0.79). BW was correlated with placental volume (R = 0.62), but not with CI (P = 0.40). BW was also correlated with local perfusion asymmetry (R = -0.71).

DATA CONCLUSION

Results demonstrate a gradient of placental function, associated with CI and suggest several ex-vivo imaging-markers that might indicate an increased risk for placental dysfunction.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY: Stage 1.

Biomarkers of Inflammation and Redox Imbalance in Umbilical Cord in Pregnancies with and without Preeclampsia and Consequent Perinatal Outcomes

OBJECTIVE

To compare redox imbalance and inflammation biomarkers in umbilical cords from pregnancies with and without preeclampsia (PE) and to analyse their relationships with perinatal outcomes.

METHODS

A controlled cross-sectional study was conducted in Maceió, Alagoas, Brazil, that involved pregnant women with PE and a group of women without the disease, through the application of a standardized questionnaire. After delivery, umbilical cord samples were collected to measure antioxidant defense, products from oxidative damage, and inflammation biomarkers such as myeloperoxidase (MPO), interleukin- (IL-) 6, IL-8, IL-10, and tumor necrosis factor-alpha (TNF-α). Statistical analyses were performed using Stata version 13.0 software and IBM Statistical Package for the Social Sciences (SPSS) 20.0, adopting a 95% confidence level (α = 0.05), with the chi-square test, the Wilcoxon-Mann-Whitney test, and the multinomial and Poisson regression tests.

RESULTS

One hundred PE pregnant women and 50 women without the disease were studied. The umbilical cords from PE pregnancies showed higher levels of reduced glutathione (GSH) (p ≤ 0.001), glutathione peroxidase (GPx) (p = 0.016), and malondialdehyde (MDA) (p = 0.028) and lower levels of IL-6 (p = 0.030) and TNF-α (p ≤ 0.001) than the other group, with some associations among these biomarkers with perinatal outcomes.

CONCLUSION

The higher levels of GSH and GPx, in addition to the lower levels of IL-6 and TNF-α, found in the PE umbilical cord, may result from adaptive mechanisms to maintain the oxidative and inflammatory balance; however, despite these changes, the damage to the cell membranes was not minimized, as the MDA level was higher in women with PE than in women without the disease. This implies that a redox imbalance is present, confirming that other physiological and adaptive mechanisms are being activated to preserve foetal health. Therefore, the present work unveils an important role of the umbilical cord in controlling redox imbalance and inflammation in PE pregnancies. Our results reinforce the necessity for continuous research on GSH as a protective compound for the perinatal outcome, especially in PE women.

Measurement of Marginal Placental Cord Insertion by Prenatal Ultrasound Was Found Not to Be Predictive of Adverse Perinatal Outcomes

OBJECTIVES

The clinical importance of marginal cord insertion (MCI) is currently controversial. In this study, we examined the association between MCI and adverse perinatal outcomes. We also evaluated the ultrasound-measured distance from the site of placental cord insertion (PCI) to the placental margin (PCI distance) and perinatal outcomes.

METHODS

This was a retrospective cohort study of MCI and control pregnancies presenting to a single institution between September 2014 and August 2016. Marginal cord insertion was diagnosed on routine anatomy ultrasound scans at 20 weeks' gestation. The primary outcome was fetal intolerance to labor. Secondary outcomes of interest included mode of delivery, gestational age at delivery, Apgar scores at 1 and 5 minutes, birth weight, delivery complications, and neonatal intensive care unit admission. The PCI distance was determined by an ultrasound review. Statistical significance was evaluated by a χ² analysis, descriptive statistics, Wilcoxon tests, and regression models with log-transformed outcomes, the PCI distance, or both as needed.

RESULTS

Of 675 abnormal cord insertion cases, we identified 183 that met inclusion criteria. We found no statistically significant association between MCI and fetal intolerance to labor (odds ratio, 1.24 [95% confidence interval, 0.55-2.80]; P = .71) or secondary outcomes. Furthermore, we found no significant correlation between perinatal outcomes and the PCI distance.

CONCLUSIONS

Our study suggests that MCI pregnancies, regardless of the specific PCI distance, might not be at increased risk of adverse perinatal outcomes. This finding questions the need for heightened antepartum surveillance of this patient population.

Maternal exposure to fine particulate matter over the first trimester and umbilical cord insertion abnormalities

BACKGROUND

Our hypothesis was that exposure to fine particulate matter (PM2.5) is related to abnormal cord insertion, which is categorized as a form of placental implantation abnormality. We investigated the association between exposure to total PM2.5 and its chemical components over the first trimester and abnormal cord insertion, which contributes to the occurrence of adverse birth outcomes.

METHODS

From the Japan Perinatal Registry Network database, we used data on 83 708 women who delivered singleton births at 39 cooperating hospitals in 23 Tokyo wards (2013-2015). We collected PM2.5 on a filter and measured daily concentrations of carbon and ion components. Then, we calculated the average concentrations over the first trimester (0-13 weeks of gestation) for each woman. A multilevel logistic-regression model with the hospital as a random effect was used to estimate the odds ratios (ORs) of abnormal cord insertion.

RESULTS

Among the 83 708 women (mean age at delivery = 33.7 years), the frequency of abnormal cord insertion was 4.5%, the median concentration [interquartile range (IQR)] of total PM2.5 was 16.1 (3.61) μg/m3 and the OR per IQR for total PM2.5 was 1.14 (95% confidence interval = 1.06-1.23). In the total PM2.5-adjusted models, total carbon, organic carbon, nitrate, ammonium and chloride were positively associated with abnormal insertion. Organic carbon was consistently, and nitrate tended to be, associated with specific types of abnormal insertion (marginal or velamentous cord insertion).

CONCLUSIONS

Exposure to total PM2.5 and some of its components over the first trimester increased the likelihood of abnormal cord insertion.

Placental abnormalities in congenital heart disease

Congenital heart disease (CHD) remains the most common birth defect in infants, and critical CHD is associated with significant rates of morbidity and mortality. With the advent of powerful yet noninvasive advanced fetal imaging, it is becoming increasingly evident that the presence of CHD in utero disrupts typical development and contributes to the lifelong morbidity in this population. Across healthy and high-risk populations, intrauterine influences can permanently alter fetal development that may manifest in complex morbidities later in life, the so-called fetal-onset-of-adult-disease (FOAD) phenomenon. The placenta plays a critical role in not only supporting fetal development, but also by adapting to specific intrauterine conditions. The role of placental health, adaptation and dysfunction, however, in CHD is not well understood. In this article, we will review current evidence relating placental health in CHD, appraise existing knowledge-gaps in the field and highlight promising new avenues to better understand the impact of placental function on fetal well-being. We will review evidence of ex vivo human placental studies that describe abnormal placental findings in pregnancies complicated by CHD, as well evidence for in vivo assessments of the human placenta. While overall clinical in vivo assessments of placental development are rather limited, we will also review emerging evidence from advanced quantitative and functional magnetic resonance imaging that are bringing new insights into placental structure and function throughout gestation. By providing novel information about placental development, we can now explore the maternal-fetal-placental connection in greater detail, and better understand the multi-factorial mechanisms that may contribute to adverse outcomes seen in survivors of CHD.

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. 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. 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<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<0.0001) as well as the birth weight (r=-0.6115, p<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 %. 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.

Abnormal umbilical cord insertions in singleton deliveries: placental histology and neonatal outcomes

AIMS

This study aimed to identify any microscopic features associated with abnormal (membranous/velamentous or marginal) placental cord insertions and to analyse their adverse neonatal outcomes.

METHODS

We retrospectively analysed the records-including pathological findings, clinical information and pregnancy outcomes-for 1060 singleton pregnancies, involving newborn delivered after 24 weeks of gestation.

RESULTS

Marginal cord insertions were identified in 26.60% of cases and membranous cord insertions in 2.64%. Subchorionic vessel thrombus was more prevalent in marginal or membranous insertions (0.97%) than in normal cord insertions (0.27%) (p=0.129). Intervillous thrombi (13.73% vs 8.41%, p<0.05) and chorioamnionitis (8.53% vs 5.48%, p=0.089) were more prevalent in normal cord insertions. Premature rupture of membranes was significantly more commonly associated with abnormal (marginal 15.25% and membranous 17.86%) than with normal (9.87%) insertions (p<0.05). Pre-eclampsia was more common in the group with membranous cord insertions (7.14%) than in the other groups (marginal 0.35%; normal 0.80%) (p<0.05). Marginal and membranous placental cord insertions were associated with earlier gestational age at delivery and smaller fetuses than in the group with normal insertions. Intrauterine fetal demise, cardiac malformations and pregestational diabetes were also more common among cases of abnormal cord insertions.

CONCLUSIONS

Subchorionic vessel thrombus and adverse pregnancy-related outcomes were more prevalent in cases of marginal/membranous cord insertion than for normal insertions.

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.

[Perinatal conditions of late preterm twins versus early term twins]

OBJECTIVE

To study the perinatal complications of late preterm twins (LPTs) versus early term twins (ETTs).

METHODS

A retrospective analysis was performed for the complications of 246 LPTs, 496 ETTs, and their mothers. The risk factors for late preterm birth were analyzed. According to gestational age, the twins were divided into five groups: 34-34⁺⁶ weeks (n=44), 35-35⁺⁶ weeks (n=70), 36-36⁺⁶ weeks (n=132), 37-37⁺⁶ weeks (n=390), and 38-38⁺⁶ weeks (n=106). The perinatal complications were compared between groups.

RESULTS

Maternal hypertension, maternal thrombocytopenia, placenta previa, and premature rupture of membranes were independent risk factors for late preterm birth in twins (P < 0.05). The LPT group had higher incidence rates of respiratory diseases, feeding intolerance, and hypoglycemia than the ETT group (P < 0.05). The 34-34⁺⁶ weeks group had a higher incidence rate of neonatal asphyxia than the 37-37⁺⁶ weeks and 38-38⁺⁶ weeks groups; and had a higher incidence rate of septicemia than 36-36⁺⁶ weeks group (P < 0.0045). The 34-34⁺⁶ weeks and 35-35⁺⁶ weeks groups had higher incidence rates of neonatal respiratory distress syndrome, neonatal apnea, and anemia than the other three groups; and had higher incidence rates of neonatal pneumonia, hypoglycemia and septicemia than the 37-37⁺⁶ weeks and 38-38⁺⁶ weeks groups (P < 0.0045). The 35-35⁺⁶ weeks group had a higher incidence rate of feeding intolerance than the 36-36⁺⁶ weeks, 37-37⁺⁶ weeks, and 38-38⁺⁶ weeks groups (P < 0.0045). The 36-36⁺⁶ weeks group had a lower incidence rate of hypoglycemia than the 34-34⁺⁶ weeks group and a higher incidence rate of hypoglycemia than the 37-37⁺⁶ weeks group (P < 0.0045).

CONCLUSIONS

Compared with ETTs, LPTs have an increased incidence of perinatal complications. The incidence of perinatal complications is associated with gestational ages in the LPTs and ETTs.

[Perinatal conditions of late preterm twins versus early term twins]

OBJECTIVE

To study the perinatal complications of late preterm twins (LPTs) versus early term twins (ETTs).

METHODS

A retrospective analysis was performed for the complications of 246 LPTs, 496 ETTs, and their mothers. The risk factors for late preterm birth were analyzed. According to gestational age, the twins were divided into five groups: 34-34+6 weeks (n=44), 35-35+6 weeks (n=70), 36-36+6 weeks (n=132), 37-37+6 weeks (n=390), and 38-38+6 weeks (n=106). The perinatal complications were compared between groups.

RESULTS

Maternal hypertension, maternal thrombocytopenia, placenta previa, and premature rupture of membranes were independent risk factors for late preterm birth in twins (P < 0.05). The LPT group had higher incidence rates of respiratory diseases, feeding intolerance, and hypoglycemia than the ETT group (P < 0.05). The 34-34+6 weeks group had a higher incidence rate of neonatal asphyxia than the 37-37+6 weeks and 38-38+6 weeks groups; and had a higher incidence rate of septicemia than 36-36+6 weeks group (P < 0.0045). The 34-34+6 weeks and 35-35+6 weeks groups had higher incidence rates of neonatal respiratory distress syndrome, neonatal apnea, and anemia than the other three groups; and had higher incidence rates of neonatal pneumonia, hypoglycemia and septicemia than the 37-37+6 weeks and 38-38+6 weeks groups (P < 0.0045). The 35-35+6 weeks group had a higher incidence rate of feeding intolerance than the 36-36+6 weeks, 37-37+6 weeks, and 38-38+6 weeks groups (P < 0.0045). The 36-36+6 weeks group had a lower incidence rate of hypoglycemia than the 34-34+6 weeks group and a higher incidence rate of hypoglycemia than the 37-37+6 weeks group (P < 0.0045).

CONCLUSIONS

Compared with ETTs, LPTs have an increased incidence of perinatal complications. The incidence of perinatal complications is associated with gestational ages in the LPTs and ETTs.

"The First Thousand Days" Define a Fetal/Neonatal Neurology Program

Gene-environment interactions begin at conception to influence maternal/placental/fetal triads, neonates, and children with short- and long-term effects on brain development. Life-long developmental neuroplasticity more likely results during critical/sensitive periods of brain maturation over these first 1,000 days. A fetal/neonatal program (FNNP) applying this perspective better identifies trimester-specific mechanisms affecting the maternal/placental/fetal (MPF) triad, expressed as brain malformations and destructive lesions. Maladaptive MPF triad interactions impair progenitor neuronal/glial populations within transient embryonic/fetal brain structures by processes such as maternal immune activation. Destructive fetal brain lesions later in pregnancy result from ischemic placental syndromes associated with the great obstetrical syndromes. Trimester-specific MPF triad diseases may negatively impact labor and delivery outcomes. Neonatal neurocritical care addresses the symptomatic minority who express the great neonatal neurological syndromes: encephalopathy, seizures, stroke, and encephalopathy of prematurity. The asymptomatic majority present with neurologic disorders before 2 years of age without prior detection. The developmental principle of ontogenetic adaptation helps guide the diagnostic process during the first 1,000 days to identify more phenotypes using systems-biology analyses. This strategy will foster innovative interdisciplinary diagnostic/therapeutic pathways, educational curricula, and research agenda among multiple FNNP. Effective early-life diagnostic/therapeutic programs will help reduce neurologic disease burden across the lifespan and successive generations.

Exploring the impact of HIV infection and antiretroviral therapy on placenta morphology

INTRODUCTION

Women living with HIV experience more adverse birth outcomes; the mechanisms are not fully understood. We examined placenta morphology and associations with birth outcomes in a Canadian cohort of women living with HIV (HIV⁺) on antiretroviral therapy (ART) from conception and HIV-uninfected (HIV^-) women.

METHODS

Term placentas from 94 women (40 HIV^-, 54 HIV⁺) were studied. Trimmed placenta weight was collected. Placenta digital photos were used to compute morphometric parameters. Regression models investigated associations between log-transformed placenta parameters and birth outcomes.

RESULTS

We observed a trend towards lower placenta weight and smaller placenta area in the HIV⁺ group, both of which were significantly associated with small for gestational age births. HIV⁺ serostatus was associated with 6-fold (95%CI 2-20) greater odds of having placenta area in the lowest quartile (<236 cm²). Cord marginality (distance from the edge) was significantly lower in the HIV⁺ group (p = 0.004), with 35% of placenta having an abnormal (marginal or velamentous) cord insertion vs. 12.5% in the HIV^- group (p = 0.01). Velamentous cord insertion was seen in 13% of placentas in the HIV⁺ vs. 0% in HIV^- group (p = 0.02). A significant correlation between cord marginality and placenta thickness was observed in the HIV^- group, with a more marginal cord being associated with a thicker placenta. This correlation was not observed in the HIV⁺ group. HIV⁺ placentas exposed to protease inhibitors were significantly less circular compared to the HIV^- group (p = 0.03).

CONCLUSION

Our data suggest that HIV/ART exposure affects placenta morphology and is associated with higher rates of abnormal cord insertion.

Performance of ultrasound for the visualization of the placental cord insertion

PURPOSE OF REVIEW

The purpose of this review was to review the literature on the performance of ultrasound for the visualization of the placental cord insertion (PCI) and for the diagnosis of abnormal placental cord insertion (APCI). APCI included both marginal cord insertion (MCI) and velamentous cord insertion (VCI) PCI.

RECENT FINDINGS

The overall rate of visualization of the PCI across all trimesters is 90.3% and for those studies routinely using color Doppler, 98.1% (P < 0.0001). Although the visualization was lower with advancing gestational age, it remained high even into the late third trimester. In all studies, where time was reported, the PCI was visualized in most cases in less than 1 min. Ultrasound performed best for the diagnosis of VCI with a sensitivity, specificity and positive predictive value of 100, 99.9 and 85.7%, respectively, with routine use of color Doppler.

SUMMARY

Ultrasound is an excellent screening test for the evaluation of PCI across all trimesters. The use of color Doppler increases the rate of visualization and should be routinely used. Ultrasound with color Doppler is also an excellent screening test for the diagnosis of VCI. However, the performance of ultrasound is reduced with the inclusion of MCI.

Circumvallate placenta and abnormal cord insertion as risk factors for intrauterine growth restriction and preterm birth: a case report

Objectives

Circumvallate placenta is a rare abnormality of placental shape. Current data indicates that a circumvallate placenta can be a risk factor for severe adverse obstetric and neonatal outcomes such as antepartum bleeding, premature delivery, oligohydramnios, intrauterine growth restriction and placental abruption. An unusual insertion of the umbilical cord can cause a reduction of perfusion and can also lead to pregnancy complications. However, the clinical significance of these pathoanatomical findings often remains unclear.

Case presentation

We report a case of a 22-year-old third gravida nullipara in 28+2 pregnancy weeks with a pathological cardiotocography (CTG) and a growth restricted fetus with oligohydramnios and pathological umbilical blood flow. Due to recurrent decelerations of fetal heart rate the baby was delivered via cesarean section. The examination of the placenta showed a circumvallate placenta and fixated umbilical cord mimicking a battledore insertion.

Conclusions

It can be concluded that circumvallate placenta may predispose to severe obstetric complications. Women with circumvallate placenta and abnormal cord insertion probably benefit from stringent follow ups in a specialized perinatal center. Histopathological examination of the placenta can be a diagnostic tool in women with recurrent obstetric complications.

Placental cord insertion distance from the placental margin and its association with adverse perinatal outcomes

OBJECTIVE

The placental cord insertion (PCI) to the placental margin has not been well studied as a continuous variable in relation to birth outcomes. We sought to evaluate the impact of PCI distance on outcomes associated with placental function and development of fetal growth restriction (FGR).

STUDY DESIGN

This was a retrospective study of singleton gestations that underwent a fetal anatomy ultrasound from 2011-2013. The PCI was recorded as the distance in centimeters from the placental margin. Patients had FGR if the overall estimated fetal weight was <10 % for gestational age or abdominal circumference <5 % in the third trimester. Delivery, obstetric, and neonatal outcomes were obtained via medical chart review. Logistic and linear regression models were used to assess the impact of PCI distance on maternal and neonatal delivery outcomes.

RESULTS

Of the 1443 women who met inclusion criteria, 93.6 % delivered at term. The mean (±SD) PCI distance was 4.4 ± 1.4 cm. There was no association between PCI and cesarean delivery, peripartum hemorrhage (PPH), pre-eclampsia, 5-min Apgar, or intrauterine fetal demise. PCI distance was statistically significantly shorter in patients requiring neonatal intensive care unit (NICU) admission (4.1 ± 1.5 cm vs. 4.4 ± 1.4 cm, p = 0.02) and was associated with lower birthweight (p = 0.01), though this association was no longer seen when corrected for gestational age. There were 3.5 % of patients who developed FGR; PCI distances from the placental edge were not significantly different for patients who developed FGR compared to those who did not (4.2 ± 1.4 cm vs. 4.5 ± 1.4 cm, p = 0.18). Furthermore, a receiver operating characteristic (ROC) curve for PCI had poor sensitivity (area under the curve [AUC] 0.57, 95 % CI 0.49-0.65).

CONCLUSION

PCI distance at the time of fetal anatomic survey is significantly associated with NICU admission, though does not appear to impact rates of preterm birth, pre-eclampsia, PPH or cesarean delivery. PCI distance in singleton gestations does not appear to be predictive of FGR.

Antenatal Diagnosis of Marginal and Velamentous Placental Cord Insertion and Pregnancy Outcomes

OBJECTIVE

To evaluate the association between antenatal diagnosis of velamentous and marginal placental cord insertions with adverse perinatal outcomes of small-for-gestational-age (SGA) birth weight (less than the 5th percentile), caesarean birth, and perinatal mortality.

METHODS

Using a diagnostic imaging database, we performed a cohort study of all consecutive singleton pregnancies (35,391), including 1,427 cases of marginal and 107 cases of velamentous cord insertion, delivered after 24 6/7 weeks of gestation between January 1, 2012, and December 31, 2015, at a single Canadian tertiary care center. Cases with placenta previa, vasa previa, no documented cord insertion, or fetal anomalies were excluded.

RESULTS

In the overall cohort, the rate of birth weight less than the 5th percentile was 5.2%, the rate of cesarean delivery was 27.1%, and the rate of perinatal mortality was 0.24%. Velamentous cord insertion was associated with SGA (relative risk [RR] 2.19, 95% CI 1.28-3.74). This persisted after controlling for smoking during pregnancy, diabetes, and hypertension (adjusted odds ratio [aOR] 1.98, 95% CI 1.03-3.84). Velamentous cord insertion was also associated with an increased risk of caesarean birth (RR=1.38, 95% CI=1.08-1,77) and perinatal death (1.87%, RR 8.15, 95% CI 2.02-32.8), a relationship that persisted after controlling for smoking during pregnancy, diabetes, and hypertension (aOR 1.53, 95% CI 1.01-2.32). Marginal cord insertion was not associated with birth weight less than the 5th percentile (RR 1.23, 95% CI 1.00-1.51), cesarean delivery (RR 1.01, 95% CI 0.92-1.10), or perinatal death (RR 1.53, 95% CI 0.62-3.78).

CONCLUSION

Antenatal diagnosis of velamentous placental cord insertion is associated with birth weight less than the 5th percentile.

Placental vascular tree characterization based on ex-vivo MRI with a potential application for placental insufficiency assessment

INTRODUCTION

Understanding regarding the whole placental vascular network structure is limited. Our aim was to quantitatively characterize the human placental vascular tree ex-vivo using high-resolution MRI.

METHODS

34 normal placentas were rinsed and injected with a solution of gelatin and contrast agent through the umbilical vessels. A sample of six placentas taken from pregnancies with intrauterine-growth-restriction (IUGR) was used to demonstrate the potential application to cases with placental insufficiency. Structural ex-vivo MR scans of the placenta were performed using high resolution T₁ weighted images. A semi-automatic method was developed to segment and characterize the placental vascular architecture: placental volume and cord insertion location; number of bifurcations, generations and vessels diameters.

RESULTS

Different vascular patterns were found in placentas with central versus marginal cord-insertion. Based on the placental volume and number of bifurcations we were able to predict birth weight. Furthermore, preliminary results on IUGR sample demonstrated the potential of this method to differentiate between small newborns with suspected IUGR from small normal newborns who reached their full growth potential. Results obtained using the automatic method were validated against manual values demonstrating no significant differences or bias. Histopathology supported the imaging findings.

DISCUSSION

This is the first study to quantitatively characterize the human placental vascular architecture using high resolution ex-vivo MRI. Different patterns of vascular architecture may be related to different functioning of the placenta and affect fetal development. This method is simple, relatively fast, provides detailed information of the placental vascular architecture, and may have important clinical applications.

Velamentous cord insertion: results from a rapid review of incidence, risk factors, adverse outcomes and screening

BACKGROUND

Velamentous cord insertion (VCI) is an umbilical cord attachment to the membranes surrounding the placenta instead of the central mass. VCI is strongly associated with vasa praevia (VP), where umbilical vessels lie in close proximity to the internal cervical os. VP leaves the vessels vulnerable to rupture, which can lead to fatal fetal exsanguination. Screening for VP using second-trimester transabdominal sonography (TAS) to detect VCI has been proposed. We conducted a rapid review investigating the quality, quantity and direction of evidence available on the epidemiology, screening test accuracy and post-screening management pathways for VCI.

METHODS

MEDLINE, Embase and the Cochrane Library were searched on 5 July 2016 and again on 11 October 2019, using general search terms for VP and VCI. Only peer-reviewed articles reporting on the epidemiology of VCI, the accuracy of the screening test and/or downstream management pathways for VCI pregnancies were included. Quality and risk of bias of each included study were assessed using pre-specified tools.

RESULTS

Forty-one relevant publications were identified; all but one were based on non-UK pregnancy cohorts, and most included relatively few VCI cases. The estimated incidence of VCI was 0.4-11% in singleton pregnancies, with higher incidence in twin pregnancies (1.6-40%). VCI incidence was also increased among pregnancies with one or more other risk factors, including in vitro fertilisation pregnancies or nulliparity. VCI incidence among women without any known risk factors was unclear. VCI was associated with adverse perinatal outcomes, most notably pre-term birth and emergency caesarean section in singleton pregnancies, and perinatal mortality in twins; however, associations varied across studies and the increased risk was typically low or moderate compared with pregnancies without VCI. In studies on limited numbers of cases, screening for VCI using TAS had good overall accuracy, driven by high specificity. No studies on post-screening management of VCI were identified.

CONCLUSIONS

Literature on VCI epidemiology and outcomes is limited and low-quality. The accuracy of second-trimester TAS and the benefits and harms of screening cannot be determined without prospective studies in large cohorts. Modelling studies may indicate the feasibility and value of studying the epidemiology of VCI and the potential impact of detecting VCI as part of a population screening programme for VP.

Clinical characteristics and perinatal outcomes of eight cases of umbilical cord vascular rupture

Objectives

To analyze the clinical characteristics and perinatal outcomes of umbilical cord vascular rupture, and to investigate the diagnosis and treatment strategies for reducing adverse perinatal outcomes.

Methods

Clinical data of patients with a singleton pregnancy with umbilical cord rupture who were admitted to Fujian Maternity and Child Health Hospital were collected. The incidence, related factors, clinical features and perinatal outcomes of umbilical cord rupture were retrospectively analyzed.

Results

There were eight cases of umbilical cord rupture (incidence rate: 1/8370). Among them, seven were secondary to umbilical cord insertion abnormality, and one may have been related to a relatively short umbilical cord and umbilical cord traction. There were eight cases of abnormal fetal heart rate, two of vaginal bleeding, five of bloody amniotic fluid, five of premature rupture of the membranes, and two of placental abruption. With regard to outcomes, 50% of patients had cesarean section, 12.5% had forceps delivery, and 50% had perinatal mortality.

Conclusions

Vaginal bleeding, amniotic fluid, fetal heart rate, and umbilical cord insertion should be closely monitored in pregnancy. When abnormal conditions occur, obstetricians should be aware of rupture of the umbilical vessels and terminate pregnancy as soon as possible, which could improve perinatal outcomes.

Early detection of velamentous cord insertion at the eighth week of gestation

Velamentous cord insertion can be diagnosed at 8 weeks of gestation, earlier than previously reported. Fetal surveillance may be informed and prognosis may be impacted by early diagnosis once viability is reached.

Placental vascular tree characterization based on ex-vivo MRI with a potential application for placental insufficiency assessment

INTRODUCTION

Understanding regarding the whole placental vascular network structure is limited. Our aim was to quantitatively characterize the human placental vascular tree ex-vivo using high-resolution MRI.

METHODS

34 normal placentas were rinsed and injected with a solution of gelatin and contrast agent through the umbilical vessels. A sample of six placentas taken from pregnancies with intrauterine-growth-restriction (IUGR) was used to demonstrate the potential application to cases with placental insufficiency. Structural ex-vivo MR scans of the placenta were performed using high resolution T₁ weighted images. A semi-automatic method was developed to segment and characterize the placental vascular architecture: placental volume and cord insertion location, number of bifurcations, generations and vessels diameters.

RESULTS

Different vascular patterns were found in placentas with central versus marginal cord-insertion. Based on the placental volume and number of bifurcations we were able to predict birth weight. Furthermore, preliminary results on IUGR sample demonstrated the potential of this method to differentiate between small newborns with suspected IUGR from small normal newborns who reached their full growth potential. Results obtained using the automatic method were validated against manual values demonstrating no significant differences or bias. Histopathology supported the imaging findings.

DISCUSSION

This is the first study to quantitatively characterize the human placental vascular architecture using high resolution ex-vivo MRI. Different patterns of vascular architecture may be related to different functioning of the placenta and affect fetal development. This method is simple, relatively fast, provides detailed information of the placental vascular architecture, and may have important clinical applications.

Structured evaluation and reporting in imaging of placenta and umbilical cord

The human placenta plays a pivotal role in development and growth of the fetus. Disorder of this multifunctional organ is central to various fetal disorders. Doppler sonography and MRI provide excellent diagnostic evaluation of the placental morphology and umbilical cord. Decades of experience in obstetric imaging have highlighted the need of careful prenatal assessment of placenta. However, in most of the routine obstetric scans, the evaluation and reporting of the placental examination is limited to the location and grade of the placenta. The purpose of this article is to review the existing literature and facilitate step-by-step evaluation of the placenta and umbilical cord by the radiologists.

Placental Implantation Disorders

Primary disorders of placental implantation have immediate consequences for the outcome of a pregnancy. These disorders have been known to clinical science for more than a century, but have been relatively rare. Recent epidemiologic obstetric data have indicated that the rise in their incidence over the last 2 decades has been iatrogenic in origin. In particular, the rising numbers of pregnancies resulting from in vitro fertilization (IVF) and the increased use of caesarean section for delivery have been associated with higher frequencies of previa implantation, accreta placentation, abnormal placental shapes, and velamentous cord insertion. These disorders often occur together.