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. 2026 Jan 26;26:191. doi: 10.1186/s12887-025-06426-6

Table 1.

Univariate analyses of the impact of risk factors on the development of DDH in the overall study population

Risk factors Control group
(n = 924)
Study group
(n = 227)
P values

Age on DDH diagnosis

(months, mean ± SD)

2.96 ± 1.50

(95% CI: 2.86–3.05)

2.92 ± 1.45

(95% CI: 2.73–3.11)

0.378
Sex (number, %)
 Girl 558 (60%) 178 (78%) < 0.001*
 Boy 366 (40%) 49 (22%)
 Firstborn girl (number, %) 244 (26%) 84 (37%) < 0.001*

 Gestation period at delivery

(weeks, mean ± SD)

38.17 ± 2.39

(95% CI: 38.01–38.32)

38.27 ± 2.07

(95% CI: 38–38.54)

0.279
 Maternal age (years, mean ± SD)

29.08 ± 5.23

(95% CI: 28.75–29.42)

28.70 ± 5.28

(95% CI: 28.01–29.39)

0.162
 Birth weight (grams, mean ± SD)

3109.50 ± 623.30

(95% CI: 3069.26–3149.75)

3211.72 ± 680.84

(95% CI: 3122.67- 3300.76)

0.15
Birth weight category
 Low (< 2500 g) 112 (12%) 20 (9%) 0.245
 Normal (2500–4000 g) 787 (85%) 198 (87%)
 High (> 4000 g) 25 (3%) 9 (4%)
Laterality (number, %)
 Unilateral DDH 168 (77%)
 Bilateral DDH 52 (23%)
Affected side of unilateral DDH (number, %)
Left 48 (21%)
 Right 127 (51%)
 Breech presentation (number, %) 55 (6%) 22 (10%) 0.034*
 Family history (number, %) 28 (%3) 3 (%1) 0.249
 Oligohydramnios (number, %) 14 (%2) 9 (%4) 0.02*
 Prematurity (number, %) 117 (13%) 26 (12%) 0.357
 Postmaturity (number, %) 11 (1%) 4 (2%) 0.513

 Multiparity (number, %)

Primipara

Multipara

405 (44%)

519 (80%)

103 (45%)

124 (55%)

0.365
 Twin pregnancy (number, %) 41 (4%) 5 (2%) 0.082

 Type of delivery (number, %)

C-section

Vaginal

570 (62%)

354 (38%)

131 (58%)

96 (42%)

0.153
 Foot deformities (number, %) 53 (6%) 23 (10%) 0.015*

Pathologic USG examination

(number, %)

 Stable dysplastic hips 138 (61%)
 Unstable hips 89 (39%)

*Low birth weight: <2500 g; Normal birth weight: 2500–4000 g; High birth weight: >4000 g. Prematurity: <37 weeks’ gestation; Postmaturity: >42 weeks’ gestation