Maternal Serum Concentrations of Selenium, Copper, and Zinc during Pregnancy Are Associated with Risk of Spontaneous Preterm Birth: A Case-Control Study from Malawi
Table 1
Characteristics of study participants for term versus preterm births.
Variable
Characteristic
Total
Term births
Preterm births
value
Maternal age (years)
Mean (SD)
25.2 (6.1)
26.32 (5.92)
24.01 (6.19)
0.011
Gestation (weeks)
Mean (SD)
35.6 (1.8)
38.00 (1.04)
33.36 (2.55)
<0.0001
Birth weight (kg)
Mean (SD)
2.6 (0.4)
3.14 (0.38)
2.12 (0.48)
<0.0001
Married/cohabitating
(%)
173 (96)
87 (96.7)
86 (94.5)
0.766
Gravidity
(%)
0.048
(i) 1-2
108 (60)
46 (51.1)
62 (68.1)
(ii) 3-5
61 (34)
38 (42.2)
23 (25.3)
(iii) ≥6
12 (6.6)
6 (6.7)
6 (6.6)
Preterm baby before
(%)
16 (9)
4 (4.4)
12 (13.2)
0.38
Education level
(%)
0.31
(i) ≥college
11 (6.1)
5 (5.6)
6 (6.6)
(ii) secondary
70 (38.7)
41 (45.6)
29 (31.9)
(iii) primary
91 (50.3)
40 (44.4)
51 (56.0)
(iv) none
9 (5)
4 (4.4)
5 (5.5)
Herbal medication use
(%)
32 (17.7)
10 (11.1)
22 (24.2)
0.035
HIV positive
(%)
27 (15)
14 (15.6)
13 (14.3)
0.975
Syphilis positive
(%)
1 (0.6)
0 (0.0)
1 (1.1)
0.018
SD: standard deviation; : number; kg: kilograms. -test used for continuous variables, chi-square or Fisher’s exact test used for categorical variables.
