Prevalence of congenital microcephaly and its risk factors in an area at risk of Zika outbreaks

Table 2 Perinatal factors associated with microcephaly phenotypes

Perinatal factors	Disproportionate microcephaly		Proportionate microcephaly
Perinatal factors	n (%)	Adjusted OR (95% CI)^a	n (%)	Adjusted OR (95% CI)^a
Maternal age^b
< 35 years old	13 (0.03)	1.90 (0.23–15.42)	131 (0.34)	1.91 (0.95–3.85)
≥ 35 years old	1 (0.01)	Ref	9 (0.12)	Ref
Parity^b
Primiparity	8 (0.04)	1.64 (0.55–4.87)	97 (0.50)	2.83 (1.95–4.10)
Multiparity	6 (0.02)	Ref	43 (0.16)	Ref
HDP^b
Yes	0 (0.00)	–	9 (0.60)	2.06 (1.04–4.07)
No	14 (0.03)	–	131 (0.29)	Ref
GDM^b
Yes	1 (0.01)	0.52 (0.07–4.04)	21 (0.31)	1.18 (0.74–1.89)
No	13 (0.03)	Ref	119 (0.30)	Ref
Maternal carrier of HBV^{c, d}
Yes	2 (0.09)	2.51 (0.55–11.53)	13 (0.59)	1.73 (0.97–3.09)
No	10 (0.04)	Ref	104 (0.39)	Ref
Preterm birth^e
Yes	6 (0.23)	14.24 (4.91–41.30)	10 (0.39)	1.29 (0.68–2.47)
No	8 (0.02)	Ref	130 (0.30)	Ref
Small for gestational age^e
Yes	0 (0.00)	–	89 (2.73)	20.76 (14.61–29.51)
No	14 (0.03)	–	51 (0.12)	Ref

OR Odds ratio, CI Confidence interval, HDP Hypertensive disorders of pregnancy, GDM Gestational diabetes mellitus, HBV Hepatitis B Virus
^aNon-microcephaly (head circumference Z-score ≥ −3.0) as the reference group
^bIn models for the associations with maternal age, GDM, HDP, and parity, these characteristics entered the model simultaneously and were mutually adjusted for each other
^cAnalyzed only among all births born in two campuses of Guangzhou Women and Children’s Medical Center
^dAdjusted for maternal age, hypertensive disorders of pregnancy, and gestational diabetes mellitus and parity, year of birth, and place of birth
^eAdjusted for maternal age, hypertensive disorders of pregnancy, gestational diabetes mellitus, and parity, sex of newborn

ISSN: 1471-2393