Table 3.
Comparison between our study and the other two Italian studies on postpartum thyroiditis that were conducted in the new millennium and that concern cohorts of women followed-up from pregnancy through month 12 postpartum.*,§
| Descriptor | This study | Filippi et al. (2) | Stagnaro-Green et al. (5) |
|---|---|---|---|
| Location (city/cities [and region]) | Straits of Messina [Sicily, Calabria] | Genova [Liguria] | Lecce & Brindisi [Puglia] |
| No. of women | 412 | 258 | 4384 |
| Ab status at pregnancy | |||
| TPOAb +ve, regardless of TgAb | 56 (13.6%) | 39 (15.1%) | 261 (6.0%) χ2 = 35.6, P = 2.4 × 10−9 OR = 2.48 (1.83–3.38) |
| TPOAb −ve, regardless of TgAb | 356 (86.4%) | 219 (84.9%) | 4123 (94.0%) |
| TgAb +ve, regardless of TPOAb | 29 (7.0%) | 21 (8.1%) | N/A |
| TgAb −ve, regardless of TPOAb | 383 (93.0%) | 237 (91.9%) | N/A |
| TPOAb +ve & TgAb +ve | 9 (2.2%) | 17 (6.6%) χ2 = 8.61, P = 0.003 OR = 0.31 (0.13–0.71) |
N/A |
| TPOAb +ve & TgAb −ve | 47 (11.4%) | 22 (8.5%) | N/A |
| TPOAb −ve & TgAb +ve | 20 (7.8%) | 4 (1.6%) χ2 = 5.0, P = 0.025 OR = 3.24 (1.1–9.6) |
N/A |
| TPOAb −ve & TgAb −ve | 336 (81.6%) | 215 (83.3%) | N/A |
| Postpartum | |||
| Thyroid dysfunction (PPT) | 63 (15.3%) | 57 (22.1%) χ2 = 5.0, P = 0.025 OR = 0.64 (0.43–0.95) |
169 (3.9%) χ2 = 107, P = 4.4 × 10−25 OR = 4.50 (3.30–6.13) |
| Permanent hypothyroidism in PPT | 34/63 (54.0%) | 28/57 (49.1%) | 92/169 (54.4%) |
| Permanent hypo in the cohort | 34/412 (8.3%) | 28/258 (10.9%) | 92/4384 (2.1%) |
| Ab status (pregnancy) in PPT | |||
| TPOAb +ve, regardless of TgAb | 39/63 (61.9%) | 27/57 (47.4%) | 97/169 (57.4%) |
| TPOAb −ve, regardless of TgAb | 24/63 (38.1%) | 30/57 (52.6%) | 72/169 (42.6%) |
| TgAb +ve, regardless of TPOAb | 17/63 (27.0%) | 12/57 (21.1%) | N/A |
| TgAb −ve, regardless of TPOAb | 46/63 (73.0%) | 45/57 (78.9%) | N/A |
| TPOAb +ve & TgAb +ve | 8/63 (12.7%) | 11/57 (19.3%) | N/A |
| TPOAb +ve & TgAb −ve | 31/63 (49.2%) | 16/57 (28.1%) χ2 = 5.61, P = 0.018 OR = 2.48 (1.16–5.31) |
N/A |
| TPOAb −ve & TgAb +ve | 9/63 (14.3%) | 1/57 (1.7%) P = 0.003 OR = 17.50 (2.2–137) |
N/A |
| TPOAb −ve & TgAb −ve | 15/63 (23.8%) | 29/57 (50.9%) χ2 = 9.44, P = 0.002 OR = 0.30 (0.14–0.66) |
N/A |
| Women with this Ab status (pregnancy) who developed PPT | |||
| TPOAb +ve, regardless of TgAb | 39/56 (69.6%) | 27/39 (69.2%) | 97/261 (37.2%) χ2 = 19.8, P = 8.4 × 10−6 OR = 3.88 (2.08–7.23) |
| TPOAb −ve, regardless of TgAb | 24/356 (6.7%) | 30/219 (13.7%) χ2 = 7.71, P = 0.0055 OR = 0.45 (0.26–0.80) |
72/4123 (1.8%) χ2 = 39.0, P = 4.3 × 10−10 OR = 4.07 (2.53–6.54) |
| TgAb +ve, regardless of TPOAb | 17/29 (58.6%) | 12/21 (57.1%) | N/A |
| TgAb −ve, regardless of TPOAb | 46/383 (12.0%) | 45/237 (20.0%) χ2 = 5.69, P = 0.017 OR = 0.58 (0.37–0.91) |
N/A |
| TPOAb +ve & TgAb +ve | 8/9 (88.9%) | 11/17 (64.7%) | N/A |
| TPOAb +ve & TgAb −ve | 31/47 (66.0%) | 16/22 (72.7%) | N/A |
| TPOAb −ve & TgAb +ve | 9/20 (45.0%) | 1/4 (25.0%) | N/A |
| TPOAb −ve & TgAb −ve | 15/336 (4.5%) | 27/215 (12.6%) χ2 = 14.20, P = 0.0005 OR = 0.32 (0.17–0.63) |
N/A |
Not listed here is a relatively old Italian study [4] on 219 women (rate of PPT = 8.7%) in whom thyroid autoantibodies started to be measured at delivery. Similar to us, the Liguria study [2] found that “No differences between women with and without PPT were observed as regards age, parity, smoking habits, gestational age, history of previous miscarriages”, and the Puglia study [5] found that “previous pregnancy, age, smoking status, were not significantly associated with PPT. “
Not to overload the table, only for significant differences statistical details are shown, with P values highlighted by the bold print. Lack of a χ2 value in the last column indicates that statistical analysis was by the Fisher’s exact test. N/A = Not applicable.