HUAM would only have an impact on those women who actually did develop preterm labor, which is difficult to predict.
Even in those women who did develop preterm labor, some believe that HUAM can be judged to be a total success only if the treatment is successful, i.
Finally, what component of the HUAM system was responsible for an effect, if any--was it the daily nursing contact, or was it the objective evidence provided by the recorded uterine contractions?
There have been trials that have analyzed only those women who developed preterm labor, trials that looked at the rate of preterm birth, some that looked at the intermediate outcome of cervical dilation, others that looked at the total HUAM package (both the recording device and the nurse contact).
At her group practice in Houston, HUAM costs about $300/week.
In her study, 57 patients with twin gestations underwent fetal fibronectin testing every 2 weeks from 24 to 34 weeks' estimated gestational age and twice daily HUAM from 24 to 36 weeks.
A positive HUAM had a sensitivity of 92% but a specificity of only 9%, a positive predictive value of 53%, and a negative predictive value of 50%.