True Knot Of Umbilical Cord Research Articles

Gender Does Matter in Perinatal Medicine

Objective: To investigate complications and outcome of pregnancies with male and female fetuses. Methods: A population-based study comparing all singleton deliveries between the years 1988 and 1999 was performed. We compared pregnancies with male vs. female fetuses. Patients with a previous cesarean section (CS) were excluded from the study. Statistical analyses with the Mantel-Haenszel technique and multiple logistic regression models were performed to control for confounders. Results: During the study period there were 55,891 deliveries of male and 53,104 deliveries of female neonates. Patients carrying male fetuses had higher rates of gestational diabetes mellitus (OR = 1.1; 95% CI 1.01–1.12; p = 0.012), fetal macrosomia (OR = 2.0; 95% CI 1.8–2.1; p < 0.001), failure to progress during the first and second stages of labor (OR = 1.2; 95% CI 1.1–1.3; p < 0.001 and OR = 1.4; 95% CI 1.3–1.5; p < 0.001, respectively), cord prolapse (OR = 1.3; 95% CI 1.1–1.6; p = 0.014), nuchal cord (OR = 1.2; 95% CI 1.1–1.2; p < 0.001) and true umbilical cord knots (OR = 1.5; 95% CI 1.3–1.7; p < 0.001). Higher rates of CS were found among male compared with female neonates (8.7 vs. 7.9%; OR = 1.1; 95% CI 1.06–1.16; p < 0.001). Using three multivariate logistic regression models and controlling for birth weight and gestational age, male gender was significantly associated with non-reassuring fetal heart rate patterns (OR = 1.5; 95% CI 1.4–1.6; p < 0.001), low Apgar scores at 5 min (OR = 1.5; 95% CI 1.3–1.8; p < 0.001) and CS (OR = 1.2; 95%CI 1.2–1.3; p < 0.001). Controlling for possible confounders like gestational diabetes, cord prolapse, failed induction, nonprogressive labor, fetal macrosomia, nuchal cord and true umbilical cord knots using the Mantel-Haenszel technique did not change the significant association between male gender and CS. Conclusion: Male gender is an independent risk factor for adverse pregnancy outcome.

Fetal arterial redistribution indicating true umbilical cord knot

True umbilical cord knot often remains undiscovered prenatally due to a lack of characteristic clinical or ultrasound signs. We present a pregnancy with favorable outcome in which a non-stress test (NST) found non-reassuring fetal status. Abnormal Doppler blood flow patterns in the descending aorta and in the middle cerebral artery revealed fetal arterial redistribution with normal circulation in the umbilical artery despite a true cord knot. The benefit of fetal Doppler assessment is discussed. Increased aortic-cerebral ratio may reflect acute hypoxic compromise caused by the transitory constriction of the true umbilical cord knot with unrecognized morphologic and circulatory signs.

Antenatal True Umbilical Cord Knot Leading to Fetal Demise

Antenatal True Umbilical Cord Knot Leading to Fetal Demise

An undetected reason for severe fetal growth retardation

In a severely growth-retarded fetus, repeated Doppler ultrasound examinations from the 23rd week of gestation on, showed normal and highly pathological blood flow velocities in the umbilical artery. A caesarean section performed in the 39th week of gestation revealed two true umbilical cord knots. Sonographic screening for umbilical cord knots may be valuable in similar cases. The use of color Doppler could help to visualize the entire course of the umbilical cord.

A comparison of umbilical cord blood gas values between newborns with and without true knots

To compare umbilical cord blood gas values in newborns with and without true knots, and to assess the potential impact of true knot formation on cord blood gases. Twelve newborn infants with true umbilical cord knots were identified and compared with a random control population of 104 newborn infants without true knots. The two groups were analyzed for 11 maternal-fetal variables to determine if they were comparable. Subsequently, the principal outcome variable of the study was evaluated: a comparison between the umbilical arterial and venous blood gas results of the true knot and control populations. The true knot and control populations were comparable with respect to the maternal-fetal variables analyzed. The umbilical cord blood gas values did not differ between groups, except for a slightly lower umbilical artery bicarbonate value in the control group (22.0 mEq/L) versus the true knot group (24.5 mEq/L), P = .025. There was no significant difference in the incidence of acidemia (umbilical artery pH less than 7.20) between the two groups. The presence of true umbilical cord knots does not alter the incidence of umbilical artery acidemia or change umbilical cord blood gas values. Review of the pertinent obstetric literature supports the hypothesis that true umbilical cord knots lack clinical significance.

Amniotic fluid index predicts the relief of variable decelerations after amnioinfusion bolus

OBJECTIVE: Our purpose was to determine whether intrapartum amniotic fluid index before amnioinfusion can be used to predict response to therapeutic amnioinfusion. STUDY DESIGN: Intrapartum patients (n = 85) with repetitive variable decelerations in fetal heart rate that necessitated amnioinfusion (10 ml/min for 60 minutes) underwent determination of amniotic fluid index before and after bolus amnioinfusion. The fetal heart tracing was scored (scorer blinded to amniotic fluid index values) for number and characteristics of variable decelerations before and 1 hour after initiation of amnioinfusion. The amnioinfusion was considered successful if it resulted in a decrease of ≥50% in total number of variable decelerations or a decrease of ≥50% in the rate of atypical or severe variable decelerations after administration of the bolus. Spontaneous vaginal births before completion of administration of the bolus (n = 18) were excluded from analysis. The probability of success of amnioinfusion in relation to amniotic fluid index was analyzed with the χ2 test for progressive sequence. RESULTS: The mean amniotic fluid index before amnioinfusion was 6.2 ± 3.3 cm. An amniotic fluid index of ≤5 cm was present in 40% of patients (27/67), and an amniotic fluid index of ≤8 cm was present in 72% of patients (48/67). The probability of success of amnioinfusion decreased with increasing amniotic fluid index before amnioinfusion (76% [16/21] when initial amniotic fluid index was 0 to 4 cm, 63% [17/27] when initial amniotic fluid index was 4 to 8 cm, 44% [7/16] when initial amniotic fluid index was 8 to 12 cm, and 33% [1/3] when initial amniotic fluid index was >12 cm, p = 0.03). The incidence of nuchal cords or true umbilical cord knots increased in relation to amniotic fluid index before amnioinfusion. CONCLUSIONS: Amniotic fluid index before amnioinfusion can be used to predict the success of amnioinfusion for relief of variable decelerations in fetal heart rate. Failure of amnioinfusion at a high amniotic fluid index before amnioinfusion may be explained by the increased prevalence of nuchal cords or true knots in the umbilical cord. (Am J Obstet Gynecol 1996;175:1066-70.)

True knot of umbilical cord resulting in fetal death; report of a case.

The occurrence of true knot of the umbilical cord is not rare; however, for such a knot to be pulled tight enough in utero to cause fetal death is a rare occurrence. Cases resulting in fetal death prior to the onset of labor are believed to be especially rare. Hennessy, 1 in reviewing the literature on this subject in 1944, found a total of 25 reported cases of true knot of the cord, to which he added 7 cases of his own. In 14 of these the knot was tight enough to result in fetal death, and in 10 death occurred prior to the onset of labor. Another case of true knot of the cord in which fetal death occurred prior to the onset of labor is herewith reported. REPORT OF A CASE Mrs. E. H., a 24-year-old white primigravida, was first seen in the prenatal clinic when she was

True knot of umbilical cord causing fetal death before labor

True knot of umbilical cord causing fetal death before labor