Primary and secondary outcomes
A study carried out in the early 1950s examined the effectiveness of sub-cutaneous oxytocin, which was used daily until symptoms resolved (Ingelman-Sundberg 1953). Participants received either oxytocin or a placebo. The main outcome in this study was duration of treatment. Overall, seven of the 45 women included in the study still had symptoms three days after starting treatment; five of the 20 women in the oxytocin group and two of the 25 in the placebo group still required treatment after three days. Although more women in the oxytocin group had no resolution of symptoms compared with controls, the difference between groups was not statistically significant (RR 3.13, 95% CI 0.63 to 14.44), Analysis 4.1.