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INFECTIOUS
DISEASES

continued from page 19

America. Congenital ZIKV syndrome is characterized by micro- The incidence of cranial molding in full-term and preterm neonates
cephaly, cerebral ventriculomegaly, cerebellar hypoplasia, central is unknown. Such molding is considered a physiologic, transient, self-
nervous system (CNS) calcifications, arthrogryposis, or other CNS, limiting deformation of the skull and is related to prolonged labor
ocular, and musculoskeletal abnormalities. On the most recent re- forces applied to the fetal head, regardless of mode of delivery. An
port from the US Zika Pregnancy Registry (USZPR), among 442 older study described 38 newborns with molding at birth and increas-
pregnancies with possible ZIKV infection, 26 fetuses or infants ing diameters of their heads in the first 3 days of life. Although we
were found to have birth defects potentially related to ZIKV, 18 of know that cranial molding improves in the first days of life, the natural
whom (4 percent of possibly infected pregnancies) had micro- course of molding is unknown. Detailed day-by-day head measure-
cephaly. Microcephaly, thus, was markedly more prevalent in the ments of molded neonatal heads are lacking from the medical litera-
USZPR than in the general population. Practicing in Texas with ture. Resolution of cranial molding was evident at 1 month of life on
documented ZIKV travel-associated disease and with gravid trav- our first patient and at 1 week on the other.
elers from Central and South America, we often take care of preg- Neonatal microcephaly deserves comprehensive workup for un-
nant women and newborns with potential exposure to ZIKV during derlying brain abnormalities or neurotropic infectious pathogens,
pregnancy, namely a travel history to endemic areas, clinical disease, including ZIKV, according to published algorithms. Craniofacial
asymptomatic exposure of the mother, or exposure of her sexual asymmetries and molding can mislead medical practitioners to un-
partner(s). Prenatal care providers now routinely screen pregnant derestimate the newborn head size and to overestimate the risk for
women for such history to identify fetuses and infants at risk for congenital infection-induced microcephaly. Pediatricians are advised
ZIKV embryopathy, per the Centers for Disease Control and Pre- to perform standardized measurements of the fetal head with non-
vention guidelines. Current algorithms for the diagnostic workup stretching measuring tape. When available, fetal ultrasonography
of newborns born to mothers with potential ZIKV exposure are can provide information on the prenatal head growth pattern. This
based on newborn findings consistent with congenital ZIKV syn- information combined with the pregnancy history, the results of
drome, including microcephaly. prenatal testing, a thorough physical examination of the newborn,
Transient neonatal craniofacial asymmetries can lead to self-re- and serial HC measurements in the first week of life may be critical
solving microcephaly. Craniofacial asymmetries are common at to confirming or ruling out microcephaly or head growth restriction.
birth. Most are the result of in utero or intrapartum molding, sub- Newborns with abnormal prenatal screens or fetal head growth
cutaneous or subperiosteal cranial hematomas, torticollis, and de- patterns or with physical characteristics of Zika-associated or other
formational asymmetries. They are diagnosed by a careful embryopathy will be candidates for early advanced testing. New-
examination of the neonatal head. Some can be suspected prenatally borns with normal prenatal screens, normal prenatal growth and
by ultrasound or can be expected due to the presence of prenatal ultrasound findings, benign postnatal examination, and steadily im-
factors such as extremes of fetal position, uterine crowding, uterine proving HC may be candidates for targeted screening and longer
leiomyomata, or oligohydramnios. observation. Neonatal blood and urine specimens as well as placen-

20 San Antonio Medicine • May 2018