Table 1.
Clinical Characteristics and Motor Behavior at 3 to 5 Months’ Postterm Age
| Variable | Infants Without Microcephaly (n = 76)a | Infants With Microcephaly (n = 35)b | Neurotypical Controls (n = 333) | P Valuec |
|---|---|---|---|---|
| Male, No. (%) | 45 (59.2) | 19 (54.3) | 192 (57.7) | NAd |
| Preterm birth, No. (%) | ||||
| <34 wk gestation | 2 (2.6) | 0 | 6 (1.8) | NAd |
| 34-36 + 6 wk gestation | 8 (10.5) | 5 (14.3) | 39 (11.7) | |
| Weeks of gestation at the time of infection, wk, No. (%) | ||||
| ≤13 | 22 (28.9) | 29 (82.9) | NA | <.001c,e |
| 14-28 | 42 (55.3) | 6 (17.1) | NA | |
| ≥29 | 12 (15.8) | 0 | NA | |
| Age at GMA, wk, No. (%) | ||||
| 9-12 | 26 (34.2) | 17 (48.6) | 129 (38.7) | NAd |
| 13-16 | 44 (57.9) | 14 (40.0) | 174 (52.3) | |
| 17-20 | 6 (7.9) | 4 (11.4) | 30 (9.0) | |
| Fidgety movements, No. (%)f | ||||
| Normal | 64 (84.2) | 0 | 333 (100) | NA |
| Abnormal exaggerated | 3 (3.9) | 0 | 0 | |
| Absent | 9 (11.8) | 35 (100) | 0 | |
| Motor Optimality Score | ||||
| Median (IQR) [range] | 23 (19-26) [7-28] | 5 (5-6) [5-9] | 26 (24-28) [21-28] | <.001g |
| Optimal range of 25-28, No. (%) | 22 (28.9) | 0 | 231 (69.4) | <.001e |
| Reduced ≤24, No. (%) | 54 (71.1) | 35 (100) | 102 (30.6) | |
| Repertoire, No. (%) | ||||
| Age adequate | 35 (46.1) | 1 (2.9) | 246 (73.9) | <.001e |
| Not age adequate | 41 (53.9) | 34 (97.1) | 87 (26.1) | |
| Movement patterns, apart from fidgety movements, median (IQR) | ||||
| Normal | 3 (2-5) | 0 (0-1) | 5 (4-7) | <.001g |
| Abnormal | 1 (0-2) | 4 (3-6) | 0 (0-1) | <.001g |
| Postural patterns, median (IQR) | ||||
| Normal | 3 (2-3) | 1 (1-1) | 3 (3-4) | <.001g |
| Abnormal | 2 (1-3) | 6 (5-8) | 1 (0-2) | <.001g |
| Movement character, No. (%)h | ||||
| Smooth and fluent | 12 (15.8) | 0 | 149 (44.7) | <.001e |
| Stiff | 22 (28.9) | 33 (94.3) | 59 (17.7) | <.001e |
| Monotonous | 38 (50.0) | 34 (97.1) | 89 (26.7) | <.001e |
| Cramped-synchronizedi | 0 | 19 (54.3) | 0 | NA |
Abbreviations: GMA, general movement assessment; IQR, interquartile range; NA, not applicable.
Refers to 76 infants without microcephaly from the Rio de Janeiro cohort who were prenatally exposed to acute maternal illness with rash and whose mothers were referred to Fundação Oswaldo Cruz (Fiocruz) in Rio de Janeiro, Brazil. Prenatal and perinatal data are reported elsewhere.2
Refers to 33 infants from the Belo Horizonte cohort plus 2 infants with microcephaly from the Rio de Janeiro cohort.
The statistics compare infants without microcephaly vs infants with microcephaly.
Matching criteria.
Pearson χ2 test or Fisher exact test.
Normal fidgety movements are small movements of moderate speed with variable acceleration of the neck, trunk, and limbs in all directions; abnormal fidgety movements have a greater amplitude, speed, and jerkiness. Whenever fidgety movements are missing altogether from 9 to 20 weeks’ postterm age, this abnormality is called absent fidgety movements.9
Mann-Whitney test.
Because only the most frequently occurring movement characters are listed here, the percentages do not sum to 100%.
A cramped-synchronized movement characteristic denotes stiff movements; limb and trunk muscles contract almost simultaneously and then relax almost simultaneously.9