[Dynamics of prevalence of functional thyroid dysfunctions among pregnant women in Moscow from 1999 to 2008].

The objective of this study was to study dynamics of prevalence of functional thyroid dysfunctions among pregnant women. The levels of TSH, free T4, and antithyroid peroxidase antibodies (ATP-AB) were measured in randomly selected women of different gestational age who applied to be registered in a maternity welfare centre in 1999-2003 (n = 215) and 2006-2008 (n = 325). The available data indicate that iodine consumption by the study populations increased during the above periods even if still remains subnormal. No statistically significant decrease in the occurrence of ATP-AB and hypothyroidism was recorded. Women carrying ATP-AB in the first and seconds trimesters of pregnancy had significantly higher TSH levels compared to those without ATP-AB. A change of diagnostic criteria for hypothyroidism (lowering the reference TSH threshold from 4.0 to 2.5 mU/l accounts for a several-fold rise (by a factor of 2-7) in the prevalence of hypothyroidism among pregnant women.