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

Abstract

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.