A dramatic increase in plagiocephaly may be due to a number of factors
MedWire News: Changes in available therapies and reimbursement policy dramatically increased the incidence of skull deformity in infants in the US, investigators have shown.
"In Texas between 1999 and 2007, the prevalence of plagiocephaly increased more than nine-fold from 3.0 cases per 10,000 live births to 28.8," write Peter Langlois (Texas Department of State Health Services) and colleagues.
Plagiocephaly manifests as a flattening of the front or rear of the skull on one side only and can be caused by a constricted intra-uterine environment, prolonged labor with the fetal head in a low position in the pelvis, oligohydramnios, or poor infant ability to rotate the neck, leading to prolonged periods spent with the head resting on one side.
It has also been suggested that the recommendation to place babies on their backs to sleep, which was made by the American Academy of Pediatrics in 1992 to try to reduce the incidence of cot death, has increased the prevalence of plagiocephaly.
To better understand trends in plagiocephaly incidence, Langlois and team studied data from the Texas Birth Defects Registry on all cases of plagiocephaly recorded in Texas between 1999 and 2007.
As reported in the Archives of Pediatric and Adolescent Medicine, 6295 cases were definitively diagnosed over the period; equivalent to an average annual increase in incidence of 21.2%.
Analysis of potential factors explaining this change suggested that a small part of the increase was due to the recommendation that babies sleep in a supine position. A slight increase in the number of pre-term births also accounted for a small part of the increase as pre-term babies are more likely to be put in a supine sleeping position and, therefore, to develop secondary deformations.
The authors were able to rule out incorrect diagnosis coding as a potential cause for the trend, as well as ruling out any effect of increased multiple births, poor neck rotation, or oligohydramnios.
However, noting that increases in plagiocephaly incidence were much more dramatic in specific health facilities, the authors speculate that the overall increase in incidence was most likely due to decreases in the number of plagiocephaly treatments authorized for reimbursement.
Concluding, the authors concede that the limitations of the data collected by the Birth Defects Registry meant they were not able to definitively "pin down an explanation for the temporal increase in plagiocephaly incidence."
If a further study is conducted, the authors note that definite linking of increased plagiocephaly incidence to change in reimbursement policy would require "an analysis of referral patterns and of use of active therapies and interventions."
By Philip Ford