Effect of prolonged hospitalization for threatened preterm labor on maternal and fetal vitamin D levels

Aim: We aimed to evaluate the effect of prolonged hospitalization for threatened preterm labor on maternal and fetal vitamin D status.
Methods: This was a retrospective cohort study, spanning 4 years, including 18 women with threatened preterm labor and 36 women with normal pregnancy, who received prenatal care for a singleton pregnancy at our center. Threatened preterm labor cases were women who were admitted to our hospital after the second trimester test, for at least 28 days, during which, the third trimester test was also performed. Controls were randomly sampled from women matched for age as well as the season during which the third trimester test was performed. Serum 25-hydroxyvitamin D concentration in maternal blood was compared between the two groups at second trimester, third trimester and in the umbilical cord blood at delivery.
Results: The mean±SD of maternal serum 25-hydroxyvitamin D concentration in the threatened preterm labor group (14.0±3.0 ng/mL) was significantly lower than that in the control group (17.8±5.9 ng/mL) (p<0.01) in the third trimester, although there was no significant difference in the second trimester (p=0.30). There was a significant reduction (p<0.01) in the maternal serum 25-hydroxyvitamin D from the second to third trimester,in the threatened preterm labor group, compared to the control group (p=0.60). There was no significant difference between the two groups in umbilical cord blood 25-hydroxyvitamin D concentrations at delivery (p=0.41).
Conclusions: Prolonged hospitalization for threatened preterm labor reduced the maternal vitamin D status, but did not influence the neonatal status at delivery.

内容要旨・審査要旨・論文本文の公開
本論文は, 著者Naoto Yonetaniの学位論文として提出され, 学位審査・授与の対象となっている。
This is the peer reviewed version of the following article: Yonetani, N. , Kaji, T. , Hichijo, A. , Nakayama, S. , Maeda, K. and Irahara, M. (2018), Effect of prolonged hospitalization for threatened preterm labor on maternal and fetal vitamin D levels. J. Obstet. Gynaecol. Res., 44: 1042-1048, which has been published in final form at https://doi.org/10.1111/jog.13620. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.