Table 1

Subject characteristics at time of enrolment

Prenatal multivitamin groups, differing in iron content


60 mg iron group n = 75
35 mg iron group n = 92
Total N = 167

Study inclusion:




a) Had not started multivitamin in current pregnancy
27 (36%)
28 (30%)
55 (33%)
b) Had discontinued multivitamin in current pregnancy
48 (64%)
64 (70%)
112 (67%)

Reasons for (a) or (b):




Nausea and/or vomiting (NVP)
62 (83%)
68 (74%)
130 (78%)
Tablet sizeψ, swallowing difficulties, other tablet properties (i.e. taste, smell)
33 (44%)
20 (22%)
53 (32%)
Constipationβ
4 (5%)
14 (15%)
18 (11%)
Abdominal pain, GI irritability, diarrhea, heartburn, reflux
10 (13%)
13 (14%)
23 (14%)
GI medical condition (i.e. IBS, Crohn's disease)
2 (3%)
2 (2%)
4 (2%)
Doctor's advice, not supplement taker, or lacked information
5 (7%)
6 (7%)
11 (7%)

Maternal age (years)
Mean ± standard deviation
30 ± 5
31 ± 5
31 ± 5

Gravidity:




First pregnancy
23 (31%)
20 (22%)
43 (26%)
Second or higher pregnancy
52 (69%)
72 (78%)
124 (74%)
Multivitamin intake in a previous pregnancy*
45/52 (87%)
59/72 (82%)
104/124 (84%)
Discontinued multivitamin in a previous pregnancy*
26/45 (58%)
28/59 (47%)
54/104 (52%)

*Data missing for 1 subject.

ψ For the subjects who reported issues with tablet size as the reason for non-adherence with previous multivitamins, 22/33 (66%) in the '60 mg' group and 13/20 (65%) in the '35 mg' group still commenced supplementation with the assigned multivitamins.

β For the subjects who reported constipation as the reason for non-adherence with previous multivitamins, 2/4 (50%) in the '60 mg' group and 12/14 (86%) in the '35 mg' group still commenced supplementation with the assigned multivitamins.

Nguyen et al. BMC Pregnancy and Childbirth 2008 8:17   doi:10.1186/1471-2393-8-17