Study Outcomes
The criteria for the primary outcome were met by
305 women in the vitamin group (6.1%), as compared
with 285 in the placebo group (5.7%) (relative
risk, 1.07; 95% confidence interval [CI], 0.91
to 1.25). There was no significant between-group
difference in any component of the primary outcome
(Table 2). Rates of maternal secondary outcomes
are shown in Table 3. There was no significant
difference in the rate of preeclampsia
between the women in the vitamin group and those
in the placebo group (7.2% and 6.7%, respectively).
Among the women who met the criteria for the
primary outcome, 164 (27.8%) had severe hypertension
only and 321 (54.4%) had preeclampsia
(of whom 40 had mild preeclampsia; 257, severe
preeclampsia; 10, the HELLP syndrome; and 14,
eclampsia). No benefit of therapy was seen in women
with severe pregnancy-associated hypertension
or mild preeclampsia with one of the primary outcome
components (relative risk, 1.07; 95% CI, 0.89
to 1.27). Two women (one in each study group)
died from peripartum cardiomyopathy. Rates of
adverse neonatal outcomes also did not differ
significantly between the groups (Table 4).
We performed one post hoc subgroup analysis
on the basis of the week of pregnancy at randomization
(