Extreme umbilical cord lengths, cord knot and entanglement: Risk factors and risk of adverse outcomes, a population-based study

<div><p>Objectives</p><p>To determine risk factors for short and long umbilical cord, entanglement and knot. Explore their associated risks of adverse maternal and perinatal outcome, including risk of recurrence in a subsequent pregnancy. To provide population based gestational age and sex and parity specific reference ranges for cord length.</p><p>Design</p><p>Population based registry study.</p><p>Setting</p><p>Medical Birth Registry of Norway 1999–2013.</p><p>Population</p><p>All singleton births (gestational age>22weeks<45 weeks) (n = 856 300).</p><p>Methods</p><p>Descriptive statistics and odds ratios of risk factors for extreme cord length and adverse outcomes based on logistic regression adjusted for confounders.</p><p>Main outcome measures</p><p>Short or long cord (<10^th or >90^th percentile), cord knot and entanglement, adverse pregnancy outcomes including perinatal and intrauterine death.</p><p>Results</p><p>Increasing parity, maternal height and body mass index, and diabetes were associated with increased risk of a long cord. Large placental and birth weight, and fetal male sex were factors for a long cord, which again was associated with a doubled risk of intrauterine and perinatal death, and increased risk of adverse neonatal outcome. Anomalous cord insertion, female sex, and a small placenta were associated with a short cord, which was associated with increased risk of fetal malformations, placental complications, caesarean delivery, non-cephalic presentation, perinatal and intrauterine death. At term, cord knot was associated with a quadrupled risk of perinatal death. The combination of a cord knot and entanglement had a more than additive effect to the association to perinatal death. There was a more than doubled risk of recurrence of a long or short cord, knot and entanglement in a subsequent pregnancy of the same woman.</p><p>Conclusion</p><p>Cord length is influenced both by maternal and fetal factors, and there is increased risk of recurrence. Extreme cord length, entanglement and cord knot are associated with increased risk of adverse outcomes including perinatal death. We provide population based reference ranges for umbilical cord length.</p></div

Odds ratios of adverse pregnancy outcomes in pregnancies with a short umbilical cord (<10th sex and parity specific percentile) in the population of singleton births in Norway 1999–2013.

<p>Odds ratios of adverse pregnancy outcomes in pregnancies with a short umbilical cord (<10th sex and parity specific percentile) in the population of singleton births in Norway 1999–2013.</p

Odds ratios of a long umbilical cord (>90^th percentile) on maternal body mass index, vertical bars represent 95% confidence interval.

<p>Odds ratios of a long umbilical cord (>90^th percentile) on maternal body mass index, vertical bars represent 95% confidence interval.</p

Odds ratios of a long cord (>90^th percentile), short cord (<10^th percentile), cord knot and entanglement according to maternal and pregnancy characteristics in singletons in Norway 1999–2013.

<p>Odds ratios of a long cord (>90^th percentile), short cord (<10^th percentile), cord knot and entanglement according to maternal and pregnancy characteristics in singletons in Norway 1999–2013.</p

Sex specific percentiles for umbilical cord length based on singleton births in Norway 1999–2013.

<p>Sex specific percentiles for umbilical cord length based on singleton births in Norway 1999–2013.</p

Odds ratios of adverse pregnancy outcomes in pregnancies with a long umbilical cord (>90th sex and parity specific percentile) in the population of singleton births in Norway 1999–2013.

<p>Odds ratios of adverse pregnancy outcomes in pregnancies with a long umbilical cord (>90th sex and parity specific percentile) in the population of singleton births in Norway 1999–2013.</p

Odds ratios of adverse pregnancy outcomes in pregnancies with cord entanglement in the population of singleton births in Norway 1999–2013.

<p>Odds ratios of adverse pregnancy outcomes in pregnancies with cord entanglement in the population of singleton births in Norway 1999–2013.</p

Odds ratios of a long umbilical cord (>90^th percentile) on parity, vertical bars represent 95% confidence interval.

<p>Odds ratios of a long umbilical cord (>90^th percentile) on parity, vertical bars represent 95% confidence interval.</p

Subcellular localization of BAT3 variants in transfected HeLa cells.

<p>Cells were transfected with BAT3 splice variants and stained after 24 hours with a monoclonal V5 antibody for evaluation by immunofluorescence microscopy. Left panel displays DAPI staining, second panel BAT3 staining, third panel merging of images and right panel shows corresponding phase contrast images. The displayed transfected cells show examples for nuclear (BAT3 full-length, upper panel), for nuclear and cytosolic (BAT3 Δ11B, middle panel) and for enhanced cytosolic staining (BAT3 Δ11B, 24, lower panel). Scale bars = 10 µm.</p

Subcellular localization of endogenous BAT3 in % of cells.

<p>Subcellular localization of endogenous BAT3 in % of cells.</p