Published in:
01-07-2019 | Thyroid Disease | Original Article
Stable consumption of swordfish favors, whereas stable consumption of oily fish protects from, development of postpartum thyroiditis
Published in: Endocrine | Issue 1/2019
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Purpose
In 236 pregnant women, we showed that selective or predominant consumption of swordfish (group A) was associated with high rates of positivity for serum thyroid autoantibodies (TPOAb and TgAb) throughout day 4 postpartum. In contrast, selective or predominant consumption of oily fish (group B) was associated with TPOAb and TgAb negativity. Rates were intermediate in group C (scanty consumption of swordfish) and group D (consumption of fish other than swordfish and oily fish). Gestational TPOAb positivity is a risk factor for postpartum thyroiditis (PPT), which evolves into permanent hypothyroidism (PH) in about 50% of cases. Purpose of this study was to verify that the different rates of thyroid autoantibodies in the four groups translated into different PPT rates.
Methods
We expanded our previous cohort (n = 412) and duration of follow-up (month 12 postpartum), and measured frequency of PPT and PH.
Results
At first timester of gestation, we confirmed the different Ab positivity rates in group A vs. group B (TPOAb = 21.7% vs. 4.7%, P < 0.0001; TgAb = 14.1% vs. 2.4%, P < 0.05). Overall, PPT prevalence was 63/412 (15.3%), but 22/92 in group A (23.9%), 4/85 in group B (4.7%; P < 0.0001 vs. group A), 17/108 (15.7%) in group C, and 16/117 (13.7%) in group D. Approximately half of the PPT women had PH, regardless of fish group.
Conclusions
In conclusion, stable consumption of oily fish (which is enriched in polyunsaturated omega-3 fatty acids) protects from PPT, while stable consumption of swordfish (which is enriched in pollutants) favors PPT. Thus, a dietary prophylaxis of PPT is possible.