Determination of vitamin D status in singleton and twin gestations using CLIA and LC-MS/MS

Magdalena Zgliczyńska; Magdalena Ostrowska; Kinga Żebrowska; Iwona Szymusik; Konrad Kowalski; Dorota Leszczyńska; Katarzyna Kosińska-Kaczyńska

doi:10.1530/EC-23-0201

Determination of vitamin D status in singleton and twin gestations using CLIA and LC-MS/MS

Endocr Connect. 2023 Sep 27;12(11):e230201. doi: 10.1530/EC-23-0201. Print 2023 Nov 1.

Authors

Magdalena Zgliczyńska¹, Magdalena Ostrowska², Kinga Żebrowska¹, Iwona Szymusik¹, Konrad Kowalski³, Dorota Leszczyńska², Katarzyna Kosińska-Kaczyńska¹

Affiliations

¹ Department of Obstetrics, Perinatology and Neonatology, Centre of Postgraduate Medical Education, Cegłowska, Warsaw, Poland.
² Department of Endocrinology, Centre of Postgraduate Medical Education, Cegłowska, Warsaw, Poland.
³ Masdiag Sp. z o.o., Stefana Żeromskiego, Warsaw, Poland.

Abstract

Objective: Vitamin D plays an important role during pregnancy. The aim was to compare vitamin D status in a group of singleton (SP) and twin pregnancies (TP) using two diagnostic methods: chemiluminescence immunoassay (CLIA) and liquid chromatography with tandem mass spectrometry (LC-MS/MS).

Design: This is a cross-sectional study.

Methods: The study was conducted in the population of SP and TP at the gestational age above 20 + 0 at the Bielanski Hospital in Warsaw, Poland, between October 2020 and January 2023. All patients had their venous blood samples collected and were given an original survey containing questions on demography and vitamin D supplementation.

Results: The study group included 53 Caucasian women with SP and 78 with TP aged from 21 to 47. Considering LC-MS/MS, patients with TP had lower concentrations of 25-hydroxyvitamin D (25(OH)D) than patients with SP. However, no significant difference was observed in the frequency of the occurrence of vitamin D deficiency (25(OH)D < 30 ng/mL). In both groups, the levels obtained with CLIA were significantly lower than in case of LC-MS/MS, however, strongly correlated. The intermethod agreement accounted for 52.4% and the Cohen's kappa coefficient was 0.142.

Conclusions: The concentration of 25(OH)D in pregnant women depends on the type of gestation (SP/TP) and on the diagnostic methods used (CLIA/LC-MS/MS). Based on LC-MS/MS, the incidence of vitamin D deficiency was low in our group and no differences occurred in its frequency between SP and TP. The intermethod agreement between CLIA and LC-MS/MS on the detection of vitamin D deficiency was low.

Significance statement: This is the first study to compare the concentration of 25(OH)D levels between SP and TP using two methods: CLIA and the gold standard - LC-MS/MS. Based on LC-MS/MS, a low incidence of vitamin D deficiency was observed in our group, in which the vast majority of patients took cholecalciferol supplements. Moreover, there were no differences in its frequency between SP and TP. However, the 25(OH)D level was significantly lower in TP. The intermethod agreement between CLIA and LC-MS/MS on the detection of vitamin D deficiency was low, which is associated with substantial clinical implications.

Keywords: chemiluminescence immunoassay; liquid chromatography with mass spectrometry; single pregnancy; twin pregnancy; vitamin D.