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Risk factors and screening timing for developmental dysplasia of the hip in preterm infants
Ga Won Jeon1, Hye Jung Choo2, Yong Uk Kwon3
1Department of Pediatrics, Inha University Hospital, Inha University College of Medicine, Incheon, Korea.
Insights
Screening for developmental dysplasia of the hip (DDH) in preterm infants before 38 weeks postmenstrual age (PMA) leads to unnecessary follow-ups. Breech presentation is not a risk factor for DDH in this population.
Area of Science:
- Neonatal care
- Pediatric orthopedics
- Medical imaging
Background:
- Delayed diagnosis of developmental dysplasia of the hip (DDH) can lead to complex treatments and hip osteoarthritis.
- Preterm infants may have unique risk factors for DDH.
Purpose of the Study:
- To identify risk factors for DDH in preterm infants.
- To determine optimal screening timing for DDH in preterm infants.
Main Methods:
- Retrospective chart review of 155 preterm infants (gestational age <32 weeks) screened for DDH via ultrasonography.
- Analysis of gestational age, birth weight, sex, and presentation in relation to DDH diagnosis.
Main Results:
- The incidence of DDH was 6.45%.
- Screening before 38 weeks postmenstrual age (PMA) increased abnormal findings by 3.76 times.
- Breech presentation increased minor abnormal findings by 3.11 times, but these resolved spontaneously.
Conclusions:
- Ultrasonography screening before 38 weeks PMA can cause overtreatment.
- Breech presentation is not a risk factor for DDH in preterm infants, though it may cause transient abnormal findings.
- DDH etiology in preterm infants differs from term infants.
Background:
The delayed diagnosis of developmental dysplasia of the hip (DDH) requires complex treatment and sometimes progresses to hip osteoarthritis.
Purpose:
This study aimed to evaluate the risk factors and screening time for DDH in preterm infants.
Methods:
A total of 155 preterm infants with a gestational age <32 weeks screened for DDH with ultrasonography were enrolled in this retrospective chart review.
Results:
The incidence of DDH was 6.45% (10 of 155). Gestational age, birth weight, sex ratio, and breech presentation did not differ significantly between infants treated for DDH (n=10) and nontreated infants (n=145) (gestational age, 29.2±1.4 weeks vs. 29.6±2.0 weeks, P=0.583; birth weight, 1,240±237 g vs. 1,295±335 g, P=0.607; female sex, 7 of 10 (70.0%) vs. 77 of 145 (53.1%), P=0.346; and breech presentation, 5 of 10 (50.0%) vs. 43 of 145 (29.7%), P=0.286, respectively). Performing the first ultrasonography earlier than 38 weeks of postmenstrual age (PMA) increased the risk of an abnormal finding by 3.76 times compared to performing it at ≥38 weeks of PMA. These abnormal findings on ultrasonography resolved spontaneously. Breech presentation increased the risk of minor abnormal findings on the first ultrasonography by 3.11 times versus nonbreech presentation and resolved spontaneously. DDH in preterm infants did not occur predominantly on the left side or in infants born with breech presentation.
Conclusion:
Performing ultrasonography screening earlier than 38 weeks of PMA caused unnecessary subsequent ultrasonography and overtreatment. Breech presentation was not a risk factor for DDH in preterm infants. However, breech presentation could increase the risk of minor abnormal findings at the 1st ultrasonography compared to nonbreech presentation, which resolved spontaneously. The etiology and risk factors for DDH in preterm infants are somewhat different from those for DDH in term infants.
