Table 1.
Number of medications by risk category and data source
| Number of Medications by Fetal Risk Category, N (%)a | |||||
|---|---|---|---|---|---|
| TERIS Fetal Risk Ratingb | Briggs & Freeman Pregnancy Recommendationb | FDA Pregnancy Categoryc | |||
| “High Risk” Category | |||||
| High | 17 (1%) | Contraindicated | 141 (12%) | X | 104 (5%) |
| Moderate | 45 (3%) | Human data suggest risk | 152 (13%) | D | 210 (10%) |
| Smalld | 20 (1%) | No or limited human data, animal data suggest high risk | 7 (1%) | ||
| No human or animal data but potential toxicity | 2 (< 1%) | ||||
| Subtotal | 82 (5%) | 302 (26%) | 314 (15%) | ||
| “Not High Risk” Category | |||||
| Minimal | 41 (2%) | Compatible or maternal benefit > fetal risk | 268 (23%) | A | 11 (1%) |
| None | 58 (3%) | Human data suggest low risk | 54 (5%) | B | 369 (17%) |
| Unlikely | 211 (12%) | No or limited human data, animal data suggest risk | 87 (8%) | ||
| No or limited human data, animal data suggest moderate risk | 73 (6%) | ||||
| No or limited human data, animal data suggest low risk | 174 (15%) | ||||
| No or limited human data, probably compatible | 120 (11%) | ||||
| Subtotal | 310 (18%) | 776 (68%) | 380 (18%) | ||
| “Undetermined” Category | |||||
| Undetermined | 1311 (77%) | No human data, no animal data | 63 (6%) | C | 1026 (49%) |
| N/Ac | 386 (18%) | ||||
| Subtotal | 1311 (77%) | 63 (6%) | 1412 (67%) | ||
| Total | 1703 | 1141 | 2106 | ||
The total number of medications in each data source presented in this table is before any de-duplication and matching across data sources
If an author provided multiple categories of fetal risk for a specific medication, the medication was assigned to the highest fetal risk category mentioned. For example, if the fetal risk was “minimal to small”, the medication was assigned to the “small” TERIS fetal risk category
In 2015, FDA implemented the Pregnancy and Lactation Labeling Rule (PLLR) requiring manufacturers to remove the pregnancy letter category and to revise the content and format of drug product labeling for drugs approved on or after June 30, 2001. In addition, for drugs approved before June 30, 2011, the PLLR requires manufacturers to remove the pregnancy letter category from labeling by June 30, 2018 (Dinatale et al. 2017; Miranda-Filho Dde et al. 2016)
According to Adam et al. (2011), even ‘small’ risks might impact decisions about exposed pregnancies (Adam et al., 2011)