Association of the IL-6 gene rs1800796 polymorphism with recurrent pregnancy loss in a population of women from northwestern China: a case-control study

Abstract

We aimed to identify whether IL-1β (rs1143627, rs1143634 and rs16944), IL-6 (rs1800796), IL-10(rs1800872 and rs1800896), and vascular endothelial growth factor (VEGF) (rs1570360) gene polymorphisms were risk factors for recurrent pregnancy loss (RPL) in a population of women in northwestern China. A total of 150 women with a history of two or more unexplained and consecutive spontaneous abortions before their 24th gestational week and 150 age-matched women with at least two normal pregnancies and no history of pregnancy loss were included in the present study as cases and controls, respectively. We extracted genomic DNA from peripheral blood, and executed genotyping with the SNaPshot technique. Logistic regression analysis was conducted to determine the odds ratios (ORs) of the associations between the polymorphisms and RPL. Of the seven polymorphisms we studied, only IL-6 rs1800796 showed a statistically significant association with RPL, as we noted an elevated risk of RPL with the G allele (OR = 1.57; 95% CI, 1.10–2.24; p = .01). The risk of RPL in women with the GG + CG genotype (OR = 1.96; 95% CI, 1.19–3.21; p = .01) was also higher than that in women with the CC genotype. The present study thus indicated that the IL-6 gene rs1800796 polymorphism may serve as an important risk factor for RPL in this group of women from northwestern China.

IMPACT STATEMENT

• What is already known on this subject? Cytokine and vascular endothelial growth factor (VEGF) gene polymorphisms may affect the risk of recurrent pregnancy loss (RPL) by modulating cytokine and VEGF expression.

• What do the results of this study add? The study results showed that the IL-6 rs1800796 single-nucleotide polymorphism constituted a risk factor for RPL in a population of women in northwestern China.

• What are the implications of these findings for clinical practice and/or further research? This study clearly reflects clinical significance as it provides a theoretical basis for the early screening of RPL by revealing that the IL-6 gene rs1800796 polymorphism increased the risk of RPL in women in northwestern China.

Keywords:

• Genetic polymorphism
• interleukin
• recurrent pregnancy loss
• vascular endothelial growth factor

Ethics approval

This study was approved by the institutional review board of Gansu Provincial Maternity and Child-care Hospital of Lanzhou City, Gansu Province.

Informed consent

Written informed consent was obtained from all participants before being included in the study.

Author contributions

Qian Liu and YaMei Li conducted, designed and wrote the paper. Jing Li and Yanxia Wang enrolled the participants and collected the data. Baohong Mao monitored the conduct of the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Research unit introduction

Gansu Provincial Maternity and Child-care Hospital is a non-profit public health and medical institution directly under the aegis of the Provincial Health Commission. Our unit is in the first batch of ‘baby-friendly hospitals’ awarded by the National Health Commission, and is located at no. 143, Qilihebei Street, Qilihe District, Lanzhou City.

The hospital was founded in 1942 and was formerly known as Gansu Province Lanzhou Advanced Midwifery Vocational School Affiliated Maternity Hospital, Gansu Province Maternity and Infant Health Hospital, Gansu Province Obstetrics and Gynaecology Hospital; and was officially renamed the Gansu Provincial Maternity and Child-care Hospital in 1978. The total construction area is 43,993 m², with 1150 beds. The number of outpatient visits to the hospital exceeds 1,600,000 person-times per year, the number of inpatients is 70,000–80,000 person-times/year, and the annual delivery volume is 20,000–30,000 person-times. The hospital has made considerable progress and has been awarded the title of ‘Advanced Group in the National Health System’ three times for its significant contribution to the province’s maternal and child health.

Data availability statement

The data used to support the findings of this study are included within the article.

Additional information

Funding

This study was funded and supported by Gansu Provincial Health Research Projects [No.GSWSKY2018-54 and No. GSWSKY2020-80].