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Case Report

A Flat Head in a Round World: Dispelling Common Myths About Plagiocephaly

Alex J. Polotsky, MD, MS; Natasha Shur, MD; Robert W. Marion, MD; Harry J. Lieman, MD

Congenital anomalies consist of either malformations or deformations. A congenital malformation is an abnormality identifiable in the neonatal period that is caused by defects in morphogenesis—a phenomenon that typically occurs in the first trimester. By contrast, congenital deformations are defined as abnormalities in form or function that are caused by environmental forces acting on normal tissue; as such, deformations typically result from problems that occur in the perinatal period, either in the third trimester or postpartum.

Plagiocephaly (ie, –oblique head”) is the most common deformation occurring in humans and refers to a misshapen, asymmetrical skull. The infant cranium—which is malleable to allow for passage through the birth canal and rapid head growth in the first year of life—is especially vulnerable to deformation. Rarely plagiocephaly results from a congenital malformation or early closure of the skull sutures, as in syndromic craniosynostosis. Historically, infant skull deformation was practiced deliberately as early as the Neolithic and Bronze ages, often as a mark of nobility. Two famous examples include the Italian Princess of the House of Este and Queen Nefertiti of Egypt. In modern times, accidental application of pressure to bones due to a variety of prenatal and postnatal factors has resulted in an increased incidence of plagiocephaly. In the medical literature this deformational form appears under various terms, including positional/nonsynostotic/occipital/posterior plagiocephaly, benign positional molding, functional lambdoid synostosis, flat-head syndrome, and plagiocephaly without synostosis (PWS).

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CASE REPORT

A 31-year-old woman (gravida 2, para 0) with unexplained infertility for 2 years conceived a single intrauterine pregnancy following standard intracytoplasmic sperm injection (ICSI). Her prenatal course was uncomplicated except for a breech presentation. A 3,800-g (8.4 lb) baby boy was born via scheduled cesarean delivery at 39 weeks’ gestation, with Apgar scores of 8/9.

No head-shape abnormalities were noticed at birth. However, on day 4 of life mild asymmetry of the face was noted during the first outpatient examination. At age 1 month head asymmetry was again noted and the parents were counseled to increase supervised –tummy time” in the prone position. At age 2 months flattening and asymmetry of the head persisted and the parents were advised to follow a repositioning protocol. At age 4 months the infantês head shape remained abnormal. The infant was otherwise meeting developmental milestones and appeared alert, active, and playful. He was referred for evaluation and nonsurgical treatment of plagiocephaly (Figures 1 and 2). At age 9 months treatment was initiated using a helmet-like cranial orthotic device.

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FIGURE 1. Facial asymmetry, including ear shift with the right ear anterior to the left. Courtesy of Cranial Technologies, Paramus, NJ.

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FIGURE 2. Plagiocephalic skull appearance: right occipital flattening; left frontal and temporal flattening. Courtesy of Cranial Technologies, Paramus, NJ.

The parents contacted their infertility physician with a concern that assisted reproduction technology (ART) had played a role in the deformation. Until their sonês diagnosis, they had never heard of plagiocephaly and feared that it indicated a birth defect and potential neurologic damage.

Key Points

Since the early 1990s the prevalence of plagiocephaly without synostosis (PWS) has increased significantly. The –Back to Sleep” position (which has dramatically reduced the incidence of sudden infant death syndrome) has been largely implicated in PWS, but there are many additional causative factors. This case report of a singleton infant conceived via assisted reproduction highlights potential misconceptions in the general public regarding deformations. This infantês abnormal head shape was diagnosed as plagiocephaly at age 4 months. The parents in this case mistakenly believed that plagiocephaly is a birth defect and feared that the cause was assisted conception. The authors suggest the incorporation of PWS into standard preconception counseling for at-risk pregnancies.

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DISCUSSION

Since the early 1990s the prevalence of PWS has increased dramatically.1 In one study of 342 infants, noticeable occipital flattening was documented in 15%.2 This excess prevalence coincided with the 1992 –Back to Sleep” campaign of the American Academy of Pediatrics, an effort to encourage parents to put their children to sleep on their backs to prevent sudden infant death syndrome (SIDS). These new guidelines—part of a successful educational campaign—have significantly reduced the incidence of SIDS. The resultant sequelae of plagiocephaly seem like minor problems by comparison, but to a parent asymmetry of a babyês head can raise significant concerns about physical appearance and neurologic development. Nonetheless, the majority of infants who sleep in the supine position never develop significant skull deformity.

The most dramatic cases stem from intrauterine mechanical forces that act on the head, particularly in the third trimester. Although the supine position is an aggravating positional factor, prenatal factors are the primary determinants of susceptibility. These include crowding of the fetus in the uterus due to multiple gestation, fibroids, bicornuate uterus and other Môllerian anomalies, and oligohydramnios. Additional risk factors for PWS include primiparity, male gender, prematurity, torticollis (abnormally twisted or bent neck), and breech presentation.3,4 Multiple-birth infants, who are more vulnerable to intrauterine crowding, have a significantly increased risk compared with singletons.3

Extensive research has focused on ART with regard to congenital anomalies in liveborn offspring. In a highly publicized report from Australia the prevalence of at least one major birth defect was 9% for in-vitro fertilization, 8.6% for ICSI, and 4.2% for naturally conceived infants.5 By contrast, a recent study of 36,062 pregnancies found no increase in the incidence of fetal chromosomal or structural abnormalities in patients receiving any type of ART.6 With the exception of multiples, there is no known increase in congenital deformations associated with ART. It is doubtful that ICSI is the cause of PWS in the singleton pregnancy presented here, whereas breech presentation is a more likely culprit.

In most cases the diagnosis of PWS is fairly straightforward. Affected infants present with a classic –parallelogram” appearance of the skull. In general, early recognition of PWS should lead to the implementation of conservative measures such as repositioning, supervised –tummy time,” physical therapy, and (in some cases) specially fitted helmets. The parents should be reassured regarding the favorable prognosis: the majority of cases resolve with time, and few require surgery (Table).

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TABLE 1. Counseling for Plagiocephaly Without Synostosis Atypical or severe cases should be referred to a craniofacial center.

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CONCLUSION

tions is an integral part of preconception counseling, the risk of deformations is seldom mentioned. The increased prevalence of PWS may deserve special discussion particularly in women at risk for multiple gestation, uterine crowding, and preterm birth. Given the elevated rates of multiple gestation associated with ART, fertility clinics in particular may consider incorporating PWS into preconception counseling. Information on the lack of association of PWS with neurologic damage and its overall favorable prognosis may help to prepare parents and ease anxiety in the neonatal period.

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Alex J. Polotsky, MD, MS, is instructor, Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology and Womenês Health, Albert Einstein College of Medicine, Bronx, NY. Natasha Shur, MD, is assistant professor, Department of Pediatrics, Brown Medical School, Providence, RI. Robert W. Marion, MD, is chief, Division of Genetics, the Childrenês Hospital at Montefiore, Bronx, NY. Harry J. Lieman, MD, is assistant professor and medical director, Montefiore Institute for Reproductive Medicine and Health, Albert Einstein College of Medicine, Bronx, NY.

References

1. Kane AA, Mitchell LE, Craven KP, Marsh JL. Observations on a recent increase in plagiocephaly without synostosis. Pediatrics. 1996;97(6 pt 1):877-885.
2. Littlefield TR, Saba NM, Kelly KM. On the current incidence of deformational plagiocephaly: an estimation based on prospective registration at a single center. Semin Pediatr Neurol. 2004;11(4):301-304.
3. Hutchinson BL, Thompson JMD, Mitchell EA. Determinants of nonsynostotic plagiocephaly: a case-control study. Pediatrics. 2003;112(4): e316-e322.
4. de Chalain TM, Park S. Torticollis associated with positional plagiocephaly: a growing epidemic. J Craniofac Surg. 2005;16(3):411-418.
5. Hansen M, Kurinczuk JJ, Bower C, Webb S. The risk of major birth defects after intracytoplasmic sperm injection and in vitro fertilization. N Engl J Med. 2002;346(10):725-730.
6. Shevell T, Malone F, Vidaver J, et al. Assisted reproductive technology and pregnancy outcome. Obstet Gynecol. 2005;106(5 pt 1):1039-1045.

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Acknowledgements

The authors thank Cranial Technologies, Paramus, NJ, for providing pictures; and Dr Jacek Sakowski for providing neonatal history.

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