Problem: Effectiveness of early administered low-dose aspirin in prevention of pregnancy-induced hypertension (PIH) and fetal growth retardation in twin pregnancies was investigated in a randomized placebo controlled, double-blind trial in 47 twin pregnancies.
Method: Twenty-four women received 100 mg of aspirin daily from mean gestational age of 17.7 wk, and 23 women ingested placebo from a mean gestational age of 18 wk until delivery. The placebo and aspirin group were similar in age, weight gain, zygosity, gravidity, parity, and obstetrical antecedents. Treatment lasted for a mean period of 16.8 wk and 18.3 wk in the placebo and aspirin groups, respectively. The mean gestational age at birth was 35.0 wk and 36.4 wk in the placebo and aspirin groups, respectively.
Results: PIH was noted in six women (26%) in the placebo group, but in only one woman (4%) in the aspirin treated patients (P < .05). The mean combined fetal weights of both twins, and the mean weight of the second twin at delivery were significantly higher in the aspirin treated mothers than in the placebo treated gravidas (mean difference of 781 g, P < .02 and mean difference of 488 g, P < .005, respectively). Intrauterine growth retardation (< 10th percentile) concerned 11 (24%) and six (13%) fetuses in the placebo and aspirin groups, respectively. No adverse effects of treatment to either the mothers or the infants were noted.
Conclusion: Low-dose aspirin reduces the incidence of PIH and has a beneficial effect on fetal growth in twin pregnancies. Additional clinical trials are needed in order to define and select subgroups of twins where aspirin treatment is recommended.