(21.11) Association between Hypothyroidism and Fetal and Maternal Outcomes during and after Pregnancy- a nationwide study

Thyroid hormone is an anabolic hormone essential for fetal growth. Hypothyroidism can affect various maternal and fetal outcomes during and after pregnancy. The impact of hypothyroidism on pregnancy has not been extensively studied.  We aim to study the association between Hypothyroidism and Fetal and Maternal Outcomes during and after Pregnancy.

Methods:

This retrospective study used a Nationwide Inpatient Sample (NIS) using International Classification of Diseases (ICD-10) codes. STATA was used for the analysis of data. Fisher's exact test was used to compare proportions, and the student’s t-test was used to compare continuous variables. Multivariate regression analysis was utilized to calculate the adjusted odds ratio(aOR). The study’s primary outcome was mortality. The secondary outcomes were length of hospital stay (LOS), total charges for hospital stay, gestational hypertension, gestational diabetes, preeclampsia, preterm labor, prolonged labor, intrapartum hemorrhage, intrauterine fetal death, neonatal respiratory distress syndrome, stillbirth, abortion, eclampsia, placenta previa, abruptio placenta, postpartum anemia, and postpartum hemorrhage.

Results:

The total number of pregnant patients included in the study was 3,436,671, and 131,185 had hypothyroidism. Patients with hypothyroidism had longer hospital LOS than patients without hypothyroidism (adjusted mean difference=0.38, 2.82 days vs. 2.51 days, p < 0.001). Other significant outcomes included higher total charges for hospital stay (adjusted mean difference= $2948, $26211 vs. $23410, p < 0.001). Among multiple maternal and fetal outcomes analyzed, significant differences were observed in the incidence of preeclampsia (aOR=1.35, 2.61% vs. 2.05%, p = 0.002), gestational diabetes (aOR=1.33,8.59% vs. 5.07%, p< 0.001), and intrapartum hemorrhage (aOR=2.11,0.32% vs. 0.26%, p = 0.005). There were no differences between the two groups in the rates of gestational hypertension, preterm labor, prolonged labor, intrauterine fetal death, neonatal respiratory distress syndrome, stillbirth, abortion, eclampsia, placenta previa, abruptio placenta, postpartum anemia, and postpartum hemorrhage.

Discussion/Conclusion:

Hypothyroidism has a significant effect on LOS, hospital charges, pre-eclampsia, gestational diabetes, and intrapartum hemorrhage.