Relationship between maternal thyroid hormones and the biochemical markers of the first trimester aneuploidy screening

The Levels of Pregnancy-Associated Plasma Protein (PAPP-A) and Chorionic Gonadotropin (β-hCG) in the Blood Serum of Women with Hypothyroidism in the 1st Trimester of Pregnancy

Introduction

Hypothyroidism occurs in pregnant women at a rate of 0.3% to 3%. The deficiency of thyroid hormones during pregnancy can lead to an increased risk of pregnancy complications and poor health of the child, particularly affecting its psychomotor development due to the intensive growth of the nervous system during gestation. The study attempted to establish the median concentrations of pregnancy-associated plasma protein PAPP-A and the free subunit of human chorionic gonadotropin β-hCG in women with hypothyroidism in the 1st trimester of pregnancy.

Objective

The study attempted to establish the median concentrations of pregnancy-associated plasma protein PAPP-A and the free subunit of human chorionic gonadotropin β-hCG in women with hypothyroidism in the 1st trimester of pregnancy.

Patients and methods

The study included 210 pregnant women between 11 and 13.6 weeks of pregnancy; 105 women were diagnosed with hypothyroidism before or during pregnancy, and 105 women of a similar body weight and gestational age had normal thyroid function.The measurements of the pregnancy parameters studied were performed using the DELFIA^® Xpress system.

Results

Differences in the multiples of the median of the PAPP-A and β-hCG levels between women with hypothyroidism and healthy women were observed.

Conclusion

Introducing correction for patients with hypothyroidism during non-invasive biochemical prenatal testing may allow obtaining more reliable results that would be the basis for referral to invasive procedures.

First-trimester placental function in levothyroxine-using pregnant women: a case-control study

We aimed to compare the pregnancy-associated plasma protein-A (PAPP-A) and the uterine artery pulsatility index (UtA PI) levels of euthyroid pregnant women using levothyroxine vs. a control group of uncomplicated pregnancies and to evaluate the effects of different levothyroxine dosages on pregnancy outcomes. We retrospectively evaluated 206 levothyroxine-using pregnant women by looking at their basic placental function markers and obstetric outcomes. A sample of 449 women whose pregnancies concluded with uncomplicated term deliveries composed of our control group. To examine the relationship between the levothyroxine dosages and the frequency of pregnancy complications, levothyroxine users were divided into different groups according to the 75, 100, and 150 mcg cutoffs. The median PAPP-A MoM levels of levothyroxine users were significantly lower at 0.94 vs. 1.11 (p < .001) and the median mean UtA PI was significantly higher than the control group at 2.08 vs. 1.74 (p < .0001). The median birth weight was significantly lower for the levothyroxine users' group at 3292 g vs. 3427 g (p < .0001). Using 75, 100, and 150 mcg dose cutoffs, PAPP-A MoM, mean UtA PI and obstetric complication frequencies were not significantly different among levothyroxine users. Significant changes in placental function markers have been observed in euthyroid levothyroxine-using pregnant women during the first trimester. However, the frequency of obstetric complications does not appear to be dose dependent.