Macroprolactin detection by precipitation with protein A-sepharose: a rapid screening method compared with polyethylene glycol precipitation.

within 21 days. The likelihood ratio for a negative result [(1 sensitivity)/specificity] was 0.59 for birth within 7 days, 0.68 for birth within 14 days, and 0.53 for birth within 21 days. The data in Table 1 are similar to those obtained in previous studies using the ELISA-based assay. Joffe et al. (1 ) reported a NPV of 99.6% and a PPV of 9.1% for 243 patients who delivered within 7 days with gestational ages between 24 and 35 weeks of gestation. Iams et al. (2 ) reported a NPV of 99.3% and a PPV of 38.9% for 192 patients who delivered within 7 days with gestational ages between 24 and 34 weeks of gestation. This group also calculated a NPV of 95% and a PPV of 40% for patients delivering within 14 days. Peaceman et al. (3 ) examined 763 patients with gestational ages of 24–34 weeks and reported a NPV of 99.5% and a PPV of 12.7% for patients who delivered in within 7 days and a NPV of 99.2% and a PPV of 16.7% for patients who delivered in within 14 days. In our study, the NPV of fFN using the TLi system compared well with data from previous reports using ELISA-based assays. For patients who delivered within 7, 14, and 21 days, the NPVs were 96.8%, 93.7%, and 93.7%, respectively.