. 2018 Mar 27;13(3):e0194814. doi: 10.1371/journal.pone.0194814

Table 2. 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.

Outcome Condition		Long cord (>90^th percentile)			Short cord(<10^th percentile)			Cord knot			Cord entanglement
Exposure		OR	95%CI		OR	95%CI		OR	95%CI		OR	95%CI
Parity	0	reference
	1	1.22	1.20	1.24	0.72	0.80	0.73	1.61	1.54	1.69	1.07	1.06	1.09
	2	1.59	1.55	1.62	0.57	0.55	0.58	2.30	2.18	2.43	1.13	1.12	1.15
	3	1.79	1.73	1.86	0.51	0.49	0.53	2.71	2.51	2.92	1.09	1.07	1.13
	4+	1.77	1.69	1.86	0.51	0.48	0.55	2.91	2.64	3.22	1.09	1.06	1.13
Maternal age (years)	<20	reference
	20–24	NS			NS			NS			NS
	25–29	1.08	1.02	1.14	NS			1.20	1.04	1.40	0.96	0.93	0.99
	30–34	1.18	1.12	1.25	0.90	0.86	0.95	1.53	1.31	1.77	0.92	0.89	0.96
	35–39	1.34	1.26	1.42	0.82	0.78	0.87	1.84	1.58	2.14	0.89	0.86	0.92
	40 +	1.45	1.35	1.56	0.85	0.79	0.91	2.18	1.84	2.59	0.85	0.81	0.89
Fetal gender	Boy	reference
	Girl	0.73	0.72	0.74	1.38	1.36	1.40	0.66	0.64	0.69	0.88	0.87	0.89
ART	Yes	NS			1.14	1.09	1.21	0.78	0.67	0.91	0.89	0.85	0.92
BMI	<18.5	reference
	18.5–24.9	1.35	1.22	1.50	0.85	0.79	0.92	NS			NS
	25–29.9	1.84	1.66	2.05	0.68	0.63	0.74	1.53	1.17	1.98	1.06	1.00	1.13
	>30	2.36	2.12	2.63	0.58	0.53	0.63	1.78	1.36	2.33	1.06	1.00	1.14
Smoking at the beginning of pregnancy	no	reference
Smoking at the beginning of pregnancy	sometimes	1.07	1.01	1.14	0.91	0.86	0.97	NS			NS
	daily	1.02	1.00	1.05	0.94	0.92	0.97	1.16	1.10	1.23	1.12	1.11	1.15
	na	0.90	0.88	0.92	1.09	1.07	1.12	0.84	0.79	0.98	0.57	0.56	0.58
Maternal height (cm)	160–169	reference
	<150	0.59	0.43	0.81	1.60	1.31	1.96	NS			0.79	0.66	0,94
	150–159	0.82	0.78	0.87	1.25	1.19	1.31	0.82	0.70	0.95	0.94	0.91	0.98
	170–179	1.24	1.20	1.28	0.87	0.82	0.79	1.16	1.06	1.27	NS
	180+	1.51	1.38	1.66	0.72	0.64	0.81	NS			NS
Pre-gestational diabetes mellitus	yes	1.76	1.63	1.90	0.55	0.49	0.62	1.38	1.13	1.67	0.70	0.65	0.75
Gestational diabetes mellitus	Yes	1.56	1.48	1.66	0.64	0.59	0.70	1.40	1.21	1.60	NS
Pre-existing hypertension	Yes	1.22	1.11	1.35	0.86	0.77	0.97	1.46	1.18	1.80	NS
Marginal cord insertion	Yes	0.95	0.92	0.99	1.20	1.16	1.23	0.88	0.81	0.95	1.39	1.37	1.42
Velamentous cord insertion	Yes	NS			1.49	1.41	1.57	0.71	0.59	0.85	1.28	1.22	1.33
Placental weight<10th percentile	Yes	0.36	0.34	0.37	2.54	2.48	2.59	0.66	0.61	0.71	NS
Placental weight>90th percentile	Yes	2.49	2.44	2.54	0.43	0.42	0.45	1.52	1.44	1.61	0.95	0.93	0.97
Birth weight<10th percentile	Yes	0.68	0.66	0.70	2.04	1.99	2.08	NS			1.22	1.20	1.24
Birth weight>90th percentile	Yes	1.82	1.79	1.86	0.50	0.48	0.51	1.13	1.07	1.20	0.75	0.73	0.76
Year of birth	1999–2003	reference
	2009–2013	0.95	0.93	0.97	NS			0.89	0.86	0.94	0.81	0.80	0.82
	2009–2013	0.95	0.93	0.97	1.06	1.04	1.08	0.75	0.72	0.79	0.85	0.84	0.86
Gestational age at birth (weeks)	22–27	reference
	28–36	NS			NS			NS			2.33	2.03	2.66
	37–41	NS			NS			NS			3.51	3.07	4.02
	42+	NS			NS			NS			3.96	3.46	4.53
Oligohydramnios	Yes	1.15	1.10	1.20	1.18	1.13	1.23	NS			1.25	1.21	1.29
Polyhydramnios	Yes	1.25	1.16	1.34	NS			1.48	1.27	1.72	NS

ART; assisted reproductive technology, BMI: Body mass index, OR; Odds ratio, CI; Confidence Interval, NS; non-significant

Table 2. Odds ratios of a long cord (>90th percentile), short cord (<10th percentile), cord knot and entanglement according to maternal and pregnancy characteristics in singletons in Norway 1999–2013.

Table 2. 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.