Table 3. Neuroimaging Findings and Trimester of Maternal Zika Virus Infection in Pregnancya.
| Infant Neuroimaging Findings | Trimester, No. (%) | Odds Ratio (95% CI) | ||
|---|---|---|---|---|
| First (n = 52) | Second (n = 37) | Third (n = 5) | ||
| Any neuroimaging abnormality | 45 (63) | 9 (13) | 1 (1) | 7.9 (3.0-20.4) |
| Brainstem hypoplasia | 26 (63) | 6 (15) | 0 | 3.0 (1.3-6.7) |
| Cerebellar hypoplasia | 24 (67) | 4 (11) | 0 | 3.3 (1.4-7.6) |
| Corpus callosum abnormality | 13 (81) | 1 (6) | 0 | 6.4 (1.7-24.2) |
| Any cortex malformation | 40 (63) | 7 (11) | 1 (2) | 6.6 (2.7-16.1) |
| Simplified gyral pattern | 39 (63) | 7 (11) | 1 (2) | 4.6 (2.0-10.4) |
| Pachygyria | 33 (62) | 7 (13) | 0 | 3.5 (1.6-7.7) |
| Polymicrogyria | 8 (73) | 1 (9) | 1 (9) | 6.4 (1.5-27.5) |
| Any brain calcifications | 42 (64) | 7 (11) | 1 (2) | 6.4 (2.6-15.6) |
| Cortico-subcortical white matter junction | 39 (65) | 7 (12) | 1 (2) | 5.6 (2.4-12.9) |
| Basal ganglia | 30 (67) | 6 (13) | 0 | 4.4 (1.9-10.1) |
| Thalamus | 19 (61) | 4 (13) | 0 | 2.5 (1.0-5.8) |
| Periventricular | 24 (63) | 4 (11) | 1 (3) | 2.9 (1.3-6.7) |
| Brainstem | 10 (71) | 2 (14) | 0 | 3.3 (1.0-11.3) |
| Cerebellum | 1 (100) | 0 | 0 | NA |
| Any ventriculomegaly | 39 (63) | 7 (11) | 1 (2) | 4.9 (2.1-11.4) |
| Mild to moderate | 19 (61) | 3 (10) | 1 (3) | 2.3 (1.0-5.5) |
| Moderate to severe | 20 (65) | 4 (13) | 0 | 2.8 (1.2-6.5) |
| Enlarged extra-axial cerebrospinal fluid spaces | 23 (66) | 3 (9) | 1 (3) | 3.0 (1.3-7.0) |
| Enlarged cisterna magna | 31 (67) | 5 (11) | 0 | 4.2 (1.9-9.5) |
| Delayed myelination | 8 (80) | 2 (20) | 0 | 27.0 (4.2-175.5) |
| Symmetry of lesions | ||||
| Symmetric | 44 (66) | 9 (13) | 1 (1) | 5.7 (0.6-58.3) |
| Not symmetric | 1 (25) | 0 | 0 | |
Abbreviation: NA, not applicable.
Odds ratios were calculated using a univariable logistic regression model in which infant neuroimaging finding is the response variable and first trimester vs second and third trimesters combined (reference group) is the independent covariate. The percentages are column percentage and the denominator is the number of infants with Zika virus infection at each trimester. The trimester of infection is unknown for 16 infants. No significant differences in the findings were noted between groups when the analyses were repeated to investigate differences between neuroimaging abnormalities and trimester of maternal Zika virus infection for infants with and without Zika virus–positive polymerase chain reaction testing confirmed after birth. The direction of odds ratios and the statistical significance remained the same.