ETA2024 Oral Presentations Oral Session 8: Pregnancy (5 abstracts)
1Aalborg University Hospital, Department of Clinical Biochemistry, Denmark; 2Aalborg University Hospital, Department of Obstetrics, Denmark; 3Aalborg University Hospital, Department of Geriatrics, Denmark
Objective: A link between levels of maternal thyroid hormones in pregnancy and the biochemical markers of placental dysfunction, soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF), has been brought forward. Sparse evidence is available on the dynamics of sFlt-1 and PlGF in early pregnancy and the association with maternal thyroid function in early pregnant women specifically.
Methods: A retrospective cohort study within the North Denmark Region Pregnancy Cohort, 2011-2015, that contained maternal blood samples (n = 17,647) drawn in early pregnancy as part of prenatal screening for chromosomal anomalies. The samples were later used for assessment of thyroid-stimulating hormone (TSH) (ADVIA Centaur XPT, Siemens Healthineers). For the present study, a random sub-group of pregnant women (n = 858) were selected for measurement of sFlt-1 and PlGF as well as β-human chorionic gonadotropin (β-hCG) (Kryptor Compact, ThermoFisher Scientific). Regression analysis was used to evaluate the association between maternal TSH and β-hCG and pregnancy week-specific percentile levels of sFlt-1 and PlGF. Results were reported as geometric mean and adjusted beta coefficient (aβ) including potential confounders.
Results: Blood samples were drawn in median pregnancy week 10 (range 4-16). When evaluating the association between maternal TSH and categories of the placental biomarkers, higher percentile levels of sFlt-1 and PlGF associated with lower TSH in crude and adjusted analyses (Table). An opposite association between the placental biomarkers and β-hCG was found, with higher levels of β-hCG for increasing levels of sFlt-1 and PlGF (Table). Finally, high levels of β-hCG (> 75 percentile) associated with lower TSH (aβ 0.60 (95% CI: 0.48-0.75)).
n | Mean TSH (mIU/l) | aβ | 95% CI | Mean β-hCG (IU/l) | aβ | 95% CI | |
sFlt-1 | |||||||
< 25 percentile | 235 | 1.18 | Ref. | 35.8 | Ref. | ||
25-75 percentile | 415 | 0.86 | 0.76 | 0.65-0.88 | 55.1 | 1.56 | 1.38-1.76 |
> 75 percentile | 208 | 0.75 | 0.66 | 0.55-0.81 | 82.6 | 2.34 | 2.05-2.67 |
PlGF | |||||||
< 25 percentile | 210 | 1.03 | Ref. | 46.4 | Ref. | ||
25-75 percentile | 407 | 0.95 | 0.97 | 0.83-1.12 | 54.9 | 1.19 | 1.05-1.35 |
> 75 percentile | 241 | 0.75 | 0.78 | 0.64-0.96 | 59.9 | 1.27 | 1.10-1.47 |
Conclusions: In a large cohort of Danish pregnant women, higher levels of sFlt-1 and PlGF associated with lower levels of TSH. In contrast, higher levels of the placental biomarkers associated with higher levels of β-hCG. Considering the physiological link between TSH and β-hCG in early pregnancy, an intermediate role of β-hCG in the association between maternal thyroid function and biochemical markers of placental function may be proposed in this early window of pregnancy.