Association between levothyroxine supplementation for hypothyroidism in late pregnancy and risk of prematurity: a population-based cohort study

Table 5 Associations between time-varying daily levothyroxine exposure and risk of prematurity

	Crude HR		Adjusted HR
Exposure	HR^a	95% CI^a	HR^b,a	95% CI^a	p -value
Time-varying daily levothyroxine exposure	0.90	0.77, 1.04	0.95	0.81, 1.11	0.5

^aHR, hazard ratio; CI, confidence interval
^bAdjusted for: maternal age at LMP, welfare recipient, urban dweller, chronic hypertension, chronic diabetes, depression and anxiety, other psychiatric disorders, asthma, epilepsy, emergency visit and/or hospitalization, endocrinologist visits, general practitioner visits, other specialist visits, tobacco dependence, alcohol dependence, other drug dependence, obesity, preeclampsia or eclampsia, gestational hypertension, gestational diabetes, placenta previa, placental abruption, prenatal care by obstetrician/gynecologist, pregnancy 12 months before LMP, folic acid supplementation 6 months before LMP until end of first trimester

ISSN: 1741-7015