PSAT271 The Impact of Maternal Autoimmune thyroid disease on neonatal thyroid conditions in Urban City Population

BACKGROUND: There is a wide spectrum of maternal autoimmune thyroid disorders (AITD) in pregnancy ranging from Graves’ hyperthyroidism (GD) to Hashimoto thyroiditis (HT), both of which share similar immunological properties. A variety of maternal thyroid autoantibodies can cross transplacentally which may potentially cause varying degrees of neonatal thyroid dysfunction. OBJECTIVE: To study the neonatal outcomes of thyroid function in mothers with AITD in urban setting. METHODS: Mothers with AITD and newborns were included for retrospective analysis over 12 months. AITD encompassed all mothers diagnosed prior/during pregnancy with either HT or GD. RESULTS: Maternal Data: A total of 147 mothers were included (HT 87%, GD 13.6%). Among mothers with HT, thyroid auto-Abs were tested in 51/127 (40%) mothers, of which 32/47(68%) were positive for TPO, 11/21(2%) positive for ATA, 2/6(33%) positive for TSI, 1/2 (50%) positive for TRAb. L-Thyroxine was administered to 90% HT mothers. Among mothers with GD, thyroid auto-Abs were tested in 17/20 (85%) mothers, of which 7/17(41%) were positive for TSI, 6/10(60%) positive for TRAb, 7/14(50%) were positive for TPO, 3/5 positive for ATA. Methimazole (MMI) was administered to 25% GD mothers. Neonatal outcome: A total of 150 neonates (115 FT, 35 PT) were born to AITD mothers. Newborn screen was abnormal in 2 infants. 7 neonates (4.6%) were tested for thyroid auto-Abs, of which 1/2 was positive for TPO, 1/2 positive for ATA, 3/3 negative for TSI, 5/5 negative for TRAb. Serum TFTs were performed in 62/150 neonates; majority 57/62(92%) were normal, 3 had mild compensated hyperthyrotropinemia (mean TSH 17.1 mIU/L, FT4 1.93 ng/dl) and were followed elsewhere. 2 neonates developed congenital hypothyroidism requiring L-Thyroxine. Infant 1: TSH 4.56mIU/L, FT4 1.1 ng/dl, TPO and ATA positive on DOL7 and had ectopic thyroid, infant born to TPO positive HT mother on Synthroid. Infant 2: TSH 149.5mIU/L, FT4 0.8 ng/dl, TSI negative on DOL7 and had hyperemic thyroid, born to TSI, TPO and TRAb positive GD mother on MMI. Overall, only 3.3% of neonates had evidence of thyroid function abnormality which may have either been transient or permanent. CONCLUSION: Although rare, mothers with AITD might potentially impair neonatal thyroid function. This may be due to various thyroid auto-Abs or anti- thyroid medication that cross transplacentally. Maternal history of AITD should therefore raise suspicion to screen neonates and thus warrants continued vigilance. Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.