True Umbilical Cord Knot Leading to Fetal Distress – an Obstetric Emergency

Background: Umbilical cord true knot is a rare condition which affects about 1% of all pregnancies. Though the incidence is lower, it often goes undetected in antenatal period despite the availability of prenatal sonography and may lead to a compromised fetal outcome as presented in this case. In this case the presence of true knot of umbilical cord was missed despite routine sonography done just 1 week prior to delivery, when patient presented to casualty with complains of decreased fetal movements since 24 hours. This modality is said to be associated with adverse fetal outcome such as birth asphyxia or in adverse cases intra uterine fetal demise. Risk factors include long cord, polyhydramnios, small sized fetus, etc.

Case Summary: 27 years old gravida two, para two, with 1 live issue with k/c/o hypothyroidism with previous lesions came with complaints of decreased fetal movement since 24 hours at 36 weeks 3 days of gestational period. The patient recorded regular ANC checkups and routine investigations within normal limits. Her USG scan done at 34.2 wks showing single loop of cord around neck and normal doppler findings. On examination her vitals were normal .Her abdominal examination showed uterus of 34 wks size, longitudinal lie, cephalic presentation and irritable with mild contractions present with scar tenderness . Her FHS were present/irregular/112 bpm with less variability. On p/v examination os was admitting tip of finger, cervix soft, 25% effaced, station high up, presenting part vertex, membrane present. She was advised admission and a cardio-tocography (CTG) was done which showed recurrent deep atypical variable decelerations with decreased beat to beat variability. An emergent cesarean section was taken. Newborn was a female diagnosed with true umbilical cord knot, 2 cm away from fetal insertion with cord length of 84 cm. The baby was shifted to NICU in view of respiratory distress.

Conclusion: Despite of modern day ultrasonography and Doppler studies, true umbilical cord knot still remains a lesser diagnosed entity and so every pregnant patients should be monitored carefully with a watch for daily fetal movement count (DFMC)and weekly non stress test (NST) for fetal well being.