The Significance of True Knot of the Umbilical Cord in Long-Term Offspring Neurological Health

Umbilical Cord Abnormalities

The umbilical cord is the connection between mother and fetus through which gases and nutrients are exchanged. It's remarkable structure allows for freedom of movement while providing a cushioned, protected conduit from mother to fetus. Fetal development and survival are dependent upon the umbilical cord. This article reviews abnormalities of the umbilical cord that can be seen with structural and chromosomal abnormalities and altered umbilical cord flow associated with fetal growth restriction and poor pregnancy outcomes.

The benefit of active management in true knot of the umbilical cord: a retrospective study

PURPOSE

To compare perinatal outcomes between active and routine management in true knot of the umbilical cord (TKUC).

METHODS

A retrospective study of singletons born beyond 22 6/7 weeks with TKUC. Active management included weekly fetal heart rate monitoring(FHRM) ≥ 30 weeks and labor induction at 36-37 weeks. Outcomes in active and routine management were compared, including composite asphyxia-related adverse outcome, fetal death, labor induction, Cesarean section (CS) or Instrumental delivery due to non-reassuring fetal heart rate (NRFHR), Apgar5 score < 7, cord Ph < 7, neonatal intensive care unit (NICU) admission and more.

RESULTS

The Active (n = 59) and Routine (n = 1091) Management groups demonstrated similar rates of composite asphyxia-related adverse outcome (16.9% vs 16.8%, p = 0.97). Active Management resulted in higher rates of labor induction < 37 weeks (22% vs 1.7%, p < 0.001), CS (37.3% vs 19.2%, p = 0.003) and NICU admissions (13.6% vs 3%, p < 0.001). Fetal death occurred exclusively in the Routine Management group (1.8% vs 0%, p = 0.6).

CONCLUSION

Compared with routine management, weekly FHRM and labor induction between 36 and 37 weeks in TKUC do not appear to reduce neonatal asphyxia. In its current form, active management is associated with higher rates of CS, induced prematurity and NICU admissions. Labor induction before 37 weeks should be avoided.

Double true umbilical cord knots coexisting with a nuchal cord with successful fetal outcome: A case report

Umbilical nodes and cords play a crucial role in fetal development and are essential for the transfer of nutrients and oxygen between the mother and the fetus. Sonographic diagnosis of umbilical nodes and cords has become an integral part of prenatal care, allowing for the early detection of abnormalities and potential complications. The umbilical cord is a vital structure connecting the fetus to the placenta, providing essential nutrients and oxygen for fetal growth and development. Sonographic examination of the umbilical cord and its associated nodes has become an indispensable tool in prenatal care, enabling the early detection of abnormalities and potential complications. This review aims to analyze the current literature on sonographic diagnosis of umbilical nodes and cords, highlighting the key points and advancements in this field. A 37-year-old booked G4P2+1A2 Nigerian woman was registered for prenatal tertiary health care at 12 weeks of gestation. The booking investigations were normal and the booking packed cell volume was 37%. She was compliant with scheduled clinic visits and routine drugs. Pregnancy was carried to term uneventfully. Elective cesarean section was successfully performed at 38 weeks of gestation owing to the patient's prior history of third-degree perineal tear. The intraoperative findings included a loose cord around the neck of the baby and double true knots along the length of the 65 cm umbilical cord. The baby was delivered with appearance, pulse, grimace, activity and respiration (APGAR) scores of 7 in the first minute, 9 in the fifth minute, and the birth weight was 3.0 kg. Mother and baby were discharged 48 h postpartum in stable clinical condition. Although the presence of true double umbilical knots is rare, its coexistence with the nuchal cord is even rarer. There are risk factors associated with true umbilical knots. The possible risk factor implicated in this index case is the gender of the fetus and maternal multiparity. True umbilical knots are usually associated with certain fetal negative outcomes of pregnancy. There are currently no evidence-based treatment options available.

Long umbilical cord and its mysterious demeanour: A case report

True knots in the umbilical cord are rare, affecting approximately 1% of all pregnancies. The diagnosis may be missed antenatally during routine ultrasonography. Many known predisposing factors are associated with true knotting. In the majority of cases, it has no bearing on foetal outcome, but may rarely be linked to intra-uterine foetal death.

A misdiagnosed case of a 150-cm umbilical cord coiled twice around the fetal neck with a true cord knot: A rare Syrian case report

The normal umbilical cord is a crucial component during pregnancy, but sometimes it could become compromised due to some abnormalities such as excessive long umbilical cord, and though they usually end up with a healthy baby, they may lead to severe consequences. Excessive long umbilical cords are found in 4% of pregnancies and represent a risk factor for nuchal cords and true knots. We report a case of a 37-year-old Syrian pregnant woman who presented to the hospital at 37 weeks of gestation asking for a C-section for a fear of ambiguous ultrasound findings that have been interpreted as fetal malformation. At delivery, a healthy baby was born with a 150-cm umbilical cord, a true knot, and double-looped nuchal cords; the formation of the loops and the knot had been attributed to the elongated cord. Besides, ultrasound imaging could sometimes be deceptive and lead to unnecessary interventions; therefore, cord anomalies should always be kept in mind because they do not always represent a justification for a C-section.

Umbilical Cord Knots: Is the Number Related to Fetal Risk?

True knots of the umbilical cord (UC) are a rare occurrence and are reported in 0.4–1.2% of deliveries. The compression of true knot of the UC can cause obstruction of the fetal circulation, leading to intra-uterine growth retardation or fetal death. Predisposing factors for the genesis of the true UC knot are numerous and include all the conditions, which lead to a relatively large uterine volume. This situation may predispose to free and excessive fetal movements. Although not all true knots lead to perinatal complications, they have been associated with adverse pregnancy outcomes, including fetal distress, fetal hypoxia, intra-uterine growth restriction (IUGR), long-term neurological damage, caesarean delivery and stillbirth. We present a rare case of operative delivery with vacuum in a multiparous woman at term of pregnancy with a double true knot of the UC. As in most cases, the diagnosis was made after delivery, as there were no fetal symptoms during pregnancy. Some authors assume that 3D power sonography may be useful in the diagnosis of true UC knots. However, 3D power Doppler cannot be considered as a definitive method. There are no specific prenatal indications to induce the physician to look for ultrasound signs suggestive of umbilical true knot. Some studies argue that cases of fetal death and fetal risk are directly related to the number of knots. We also support this thesis, even if further observational and retrospective studies are needed to demonstrate it.

The perils of true knot of the umbilical cord: antepartum, intrapartum and postpartum complications and clinical implications

BACKGROUND

True knot of the umbilical cord (TKUC) is found in 0.3-2.1% of pregnancies and is associated with an increased risk of adverse perinatal outcomes.

METHODS

A retrospective cohort study including all singleton pregnancies delivered from 2011 to 2019 was performed. Diagnosis of TKUC was made postnatally, immediately after delivery of the baby. Comparison was made between pregnancies with and without TKUC regarding maternal, fetal and neonatal adverse outcome.

RESULTS

Overall, 867/85,541 (1%) pregnancies were diagnosed with TKUC. Maternal age, BMI, gravidity and parity were significantly higher in pregnancies with TKUC as well as higher rate of induction of labor, meconium-stained amniotic fluid, and delivery prior to 37 weeks. The rate of cesarean deliveries due to non-reassuring-fetal monitor was significantly higher in pregnancies with TKUC. Overall, there were 2.5% IUFD in pregnancies with TKUC vs. 1% in pregnancies without TKUC (p < 0.001). Importantly, the rate of IUFD prior to 37 weeks of gestation was not significantly higher in the group with TKUC, however, the rate of IUFD after 37 weeks of gestation was 10 folds higher in fetuses with TKUC, 0.9% vs. 0.08% (p < 0.001). Significantly, more neonates with TKUC needed phototherapy or suffered from hypoglycemia. There were no differences in the 5 min Apgar scores, admission to the NICU and number of days of hospitalization.

CONCLUSION

Pregnancies complicated with TKUC are associated with a tenfold higher risk of IUFD beyond 37 weeks of gestation. To the results of this study suggest that it would be prudent to induce labor around 37 weeks of gestation in pregnancies with prenatal diagnosis of TKUC. It may be warranted to use continuous fetal monitoring during labor and delivery in those cases were antenatal diagnosis of TKUC is made.