Complex umbilical cord entanglement

Are reduced fetal movements "merely" a maternal perception or truly a reflection of umbilical cord complications? A clinical trial

OBJECTIVE

To characterize obstetric outcomes and the association with umbilical cord (UC) complications among women complaining of reduced fetal movements (RFMs).

METHODS

This retrospective cohort compared women with a perception of RFMs within 2 weeks prior to delivery with women who reported no changes in fetal movements in terms of maternal characteristics and neonatal outcomes. A primary outcome of UC complications at delivery was defined. Multivariable regression analysis was performed to identify independent associations with RFMs and UC complications.

RESULTS

In all, 46 103 women were included, 2591 (5.6%) of whom reported RFMs and 43 512 (94.4%) in the control group. Compared with controls, the RFM group was more likely to be nulliparous (42.6% vs 32.2%, P < 0.001), smokers (6.4% vs 5.4%, P = 0.029), or obese (body mass index >30) (16.4% vs 11.6%, P < 0.001). They were also more likely to have an anterior placenta (56.2% vs 51.8%, P < 0.001) and poly/oligohydramnios (0.7% vs 0.4%, P = 0.015 and 3.6% vs 2.1%, P < 0.001, respectively). Induction of labor was more common in the RFM group (33.9% vs 19.7%, P < 0.001), as well as meconium (16.8% vs 15.0%, P = 0.026) and vacuum extractions (10.1% vs 8.0%, P < 0.001). Higher rates of stillbirth and the severe composite neonatal outcome were observed in the RFM group (1.5% vs 0.2%, P < 0.001 and 0.6% vs 0.3%, P = 0.010, respectively). The RFM group was characterized by higher rates of triple nuchal cord (P = 0.015), UC around body or neck (32.2% vs 29.6%, P = 0.010), and true knot (2.3% vs 1.4%, P = 0.002). Multivariable logistic regression found RFMs to be independently associated with triple nuchal cord and with a true cord knot. A sub-analysis including only cases of stillbirth (n = 127) revealed even higher rates of UC complications: 7% of all stillbirths presented with a true cord knot (20% true knots were found in stillbirths preceded by RFMs vs 6.1% in stillbirth cases without RFMs). Additionally, 33.8% of all stillbirths presented with nuchal cord (40% preceded by RFMs vs 33.3% without RFMs).

CONCLUSIONS

RFMs are associated with increased risk of UC complications observed at delivery, as well as increased risk of stillbirth and neonatal adverse outcomes.

Passive Fetal Movement Recognition Approaches Using Hyperparameter Tuned LightGBM Model and Bayesian Optimization

Fetal movement is an important clinical indicator to assess fetus growth and development status in the uterus. In recent years, a noninvasive intelligent sensing fetal movement detection system that can monitor high-risk pregnancies at home has received a lot of attention in the field of wearable health monitoring. However, recovering fetal movement signals from a continuous low-amplitude background that is heavily contaminated with noise and recognizing real fetal movements is a challenging task. In this paper, fetal movement can be efficiently recognized by combining the strength of Kalman filtering, time and frequency domain and wavelet domain feature extraction, and hyperparameter tuned Light Gradient Boosting Machine (LightGBM) model. Firstly, the Kalman filtering (KF) algorithm is used to recover the fetal movement signal in a continuous low-amplitude background contaminated by noise. Secondly, the time domain, frequency domain, and wavelet domain (TFWD) features of the preprocessed fetal movement signal are extracted. Finally, the Bayesian Optimization algorithm (BOA) is used to optimize the LightGBM model to obtain the optimal hyperparameters. Through this, the accurate prediction and recognition of fetal movement are successfully achieved. In the performance analysis of the Zenodo fetal movement dataset, the proposed KF + TFWD + BOA-LGBM approach's recognition accuracy and F1-Score reached 94.06% and 96.85%, respectively. Compared with 8 existing advanced methods for fetal movement signal recognition, the proposed method has better accuracy and robustness, indicating its potential medical application in wearable smart sensing systems for fetal prenatal health monitoring.

Amnioinfusion and Bed Rest May Effectively Improve the Insufficient Circulation of the Umbilical Cord in Pregnant Women With Hyper-Coiled Cord and Oligohydramnios

We experienced two cases with hyper-coiled cord in which fetal-umbilical-placental circulation was improved after amnioinfusion or bed rest. Therefore, amnioinfusion and bed rest to reduce the compression of the vulnerable umbilical cord in cases of hyper-coiled cord might improve the pathologic fetal-umbilical-placental circulation.

Current Perspectives of Prenatal Sonographic Diagnosis and Clinical Management Challenges of Complex Umbilical Cord Entanglement

Diagnosis of potential umbilical cord compromise, namely, true knots of the umbilical cord and nuchal cords has been enabled with increasing accuracy with current enhanced prenatal sonography. Often an incidental finding at delivery, the incidence of true knots of the umbilical cord has been estimated at between 0.04% and 3% of deliveries. This condition has been reported to account for a 4 to 10-fold increase of stillbirth and perinatal morbidity of 11% of cases. Nuchal cords, commonly observed at the delivery of uncompromised, non-hypoxic non-acidotic newborns occur more frequently with single nuchal cords noted in between 20% and 35% of all deliveries at term. Multiple nuchal cords are considerably less frequent, with decreasing frequencies inverse to the number of nuchal cord loops. While clearly single (and likely double) nuchal cords are almost uniformly associated with favorable neonatal outcomes, emerging data suggest that cases of ≥3 loops of nuchal cords are more likely to be associated with an increased risk of adverse perinatal outcome (either stillbirth or compromised neonatal condition at delivery). We define cases of a true knot of the umbilical cord, cases of ≥3 loops of nuchal cords, any combination of a true knot and nuchal cord, or any umbilical cord entanglement (nuchal or true knot) in the presence of a single umbilical artery, in singleton gestations as complex umbilical cord entanglement. Two concurrent developments, the increase in accuracy of prenatal sonographic diagnosis of complex umbilical cord entanglement and recent data confirming fatal compromise of the umbilical circulation in approximately 20% of cases of stillbirth, suggest that establishing governing body guidelines for reporting of potential umbilical cord compromise, and recommendation of consideration for early-term delivery of select cases, may be warranted. This commentary will address current perspectives of prenatal diagnosis and clinical management challenges of complex umbilical cord entanglement.

Current Perspectives of Prenatal Sonographic Diagnosis and Clinical Management Challenges of Nuchal Cord(s)

Umbilical cord accidents preceding labor are uncommon. In contrast, nuchal cords are a very common finding at delivery, with reported incidences of a single nuchal cord of approximately between 20% and 35% of all singleton deliveries at term. Multiple loops occur less frequently, with reported incidence rates inverse to the number of nuchal cords involved. Rare cases of up to 10 loops of nuchal cord have been reported. While true knots of the umbilical cord have been associated with a 4–10-fold increased risk of stillbirth, nuchal cord(s) are most often noted at delivery of non-hypoxic non-acidotic newborns, without any evidence of subsequent adverse neonatal outcome. Prior to ultrasound, nuchal cords were suspected clinically following subtle (spontaneous or evoked) electronic fetal heart rate changes. Prenatal sonographic diagnosis, initially limited to real-time gray-scale ultrasound, currently entails additional sonographic modalities, including color Doppler, power Doppler, and three-dimensional sonography, which have enabled increasingly more accurate prenatal sonographic diagnoses of nuchal cord(s). In contrast to true knots of the umbilical cord (which are often missed at sonography, reflecting the inability to visualize the entire umbilical cord, and hence are often incidental findings at delivery), nuchal cord(s), reflecting their well-defined and sonographically accessible anatomical location (the fetal neck), lend themselves with relative ease to prenatal sonographic diagnosis, with increasingly high sensitivity and specificity rates. While current literature supports that single (and possibly double) nuchal cords are not associated with increased adverse perinatal outcome, emerging literature suggests that cases of ≥3 loops of nuchal cords or in the presence of a coexisting true knot of the umbilicus may be associated with an increased risk of stillbirth or compromised neonatal status at delivery. This commentary will address current perspectives of prenatal sonographic diagnosis and clinical management challenges associated with nuchal cord(s) in singleton pregnancies.

Association between maternally perceived quality and pattern of fetal movements and late stillbirth

We investigated fetal movement quality and pattern and association with late stillbirth in this multicentre case-control study. Cases (n = 164) had experienced a non-anomalous singleton late stillbirth. Controls (n = 569) were at a similar gestation with non-anomalous singleton ongoing pregnancy. Data on perceived fetal movements were collected via interviewer-administered questionnaire. We compared categorical fetal movement variables between cases and controls using multivariable logistic regression, adjusting for possible confounders. In multivariable analysis, maternal perception of the following fetal movement variables was associated with decreased risk of late stillbirth; multiple instances of 'more vigorous than usual' fetal movement (aOR 0.52, 95% CI 0.32-0.82), daily perception of fetal hiccups (aOR 0.28, 95%CI 0.15-0.52), and perception of increased length of fetal movement clusters or 'busy times' (aOR 0.23, 95%CI 0.11-0.47). Conversely, the following maternally perceived fetal movement variables were associated with increased risk of late stillbirth; decreased frequency of fetal movements (aOR 2.29, 95%CI 1.31-4.0), and perception of 'quiet or light' fetal movement in the evening (aOR 3.82, 95%CI 1.57-9.31). In conclusion, women with stillbirth were more likely than controls to have experienced alterations in fetal movement, including decreased strength, frequency and in particular a fetus that was 'quiet' in the evening.

A placenta clinic approach to the diagnosis and management of fetal growth restriction

Effective detection and management of fetal growth restriction is relevant to all obstetric care providers. Models of best practice to care for these patients and their families continue to evolve. Since much of the disease burden in fetal growth restriction originates in the placenta, the concept of a multidisciplinary placenta clinic program, managed primarily within a maternal-fetal medicine division, has gained popularity. In this context, fetal growth restriction is merely one of many placenta-related disorders that can benefit from an interdisciplinary approach, incorporating expertise from specialist perinatal ultrasound and magnetic resonance imaging, reproductive genetics, neonatal pediatrics, internal medicine subspecialties, perinatal pathology, and nursing. The accurate diagnosis and prognosis for women with fetal growth restriction is established by comprehensive clinical review and detailed sonographic evaluation of the fetus, combined with uterine artery Doppler and morphologic assessment of the placenta. Diagnostic accuracy for placenta-mediated fetal growth restriction may be enhanced by quantification of maternal serum biomarkers including placenta growth factor alone or combined with soluble fms-like tyrosine kinase-1. Uterine artery Doppler is typically abnormal in most instances of early-onset fetal growth restriction and is associated with coexistent preeclampsia and underlying maternal vascular malperfusion pathology of the placenta. By contrast, rare but potentially more serious underlying placental diagnoses, such as massive perivillous fibrinoid deposition, chronic histiocytic intervillositis, or fetal thrombotic vasculopathy, may be associated with normal uterine artery Doppler waveforms. Despite minor variations in placental size, shape, and cord insertion, placental function remains, largely normal in the general population. Consequently, morphologic assessment of the placenta is not currently incorporated into current screening programs for placental complications. However, placental ultrasound can be diagnostic in the context of fetal growth restriction, for example in Breus' mole and triploidy, which in turn may enhance diagnosis and management. Several examples are illustrated in our figures and supplementary videos. Recent advances in the ability of multiparameter screening and intervention programs to reduce the risk of severe preeclampsia will likely increase efforts to deliver similar improvements for women at risk of fetal growth restriction. Placental pathology is important because the underlying pathologies associated with fetal growth restriction have a wide range of recurrence risks. Rare conditions such as massive perivillous fibrinoid deposition or chronic histolytic intervillositis may recur in >50% of subsequent pregnancies. Postpartum care in a placenta-focused program can provide effective counseling for modifiable maternal risk factors, and can assist in planning future pregnancy care based on the pathologic basis of fetal growth restriction.

Pathology of the stillborn infant for the general pathologist: part 1

As the information obtained from previable fetal and stillbirth autopsies is used not only to explain the loss to the parents, but for future pregnancy planning, general pathologists need to be comfortable in dealing with these autopsies. The importance of an adequate fetal examination has been emphasized in a recent policy on the subject by the American Board of Pathology http://www.abpath.org/FetalAutopsyPolicy.pdf. This review paper covers the approach to the fetal and stillbirth autopsy. This first article covers the approach to the nonanomalous and anomalous autopsy. Hydrops fetalis will be covered in the second part of this series to be published subsequently.

Umbilical cord accidents and legal implications

Umbilical cord accidents (UCA) are a significant cause of stillbirth. Although infrequent, litigation may occur when there is a poor outcome associated with UCA. With advances in imaging, the ability to identify UCA by ultrasound and magnetic resonance imaging raises awareness of the risk of a poor outcome. Management of a pregnancy with an identified UCA may require more fetal surveillance by both the mother and caregiver. This is especially important if there is a previous history of UCA with or without stillbirth. UCA should be an acknowledged risk which is part of prenatal screening. In the event of a poor outcome associated with UCA, it is recommended that the patient be fully informed of all prenatal information including images. Excellent communication with parents who are looking for answers after a tragic outcome may help to decrease litigation risk.

Fetal demise due to cord entanglement in the early second trimester

In this report, we describe a rare cause of in utero fetal death, a complex entanglement of the umbilical cord around the fetal neck. At the 16th gestational week of pregnancy, routine fetal ultrasonography showed no fetal heartbeat. Thereafter, the fetus was delivered vaginally in the breech presentation. The neck was found to be encircled by multiple tight loops of the umbilical cord. Other than a thin and elongated neck, there were no dysmorphic features and no chromosomal abnormality on cytogenetic analysis.