Resistance of uterine radial artery blood flow is positively correlated with peripheral blood NK cell fraction in patients with unexplained recurrent spontaneous abortion.

Koo, Hwa Seon; Yi, Hyun Jeong; Lee, Min Young; Ahn, Hyun Suk; Choi, Min Hye; Sung, Na Young; Hwang, Yu Im; Song, In Ok; Koong, Mi Kyoung; Kang, Inn Soo; Yang, Kwang Moon

doi:2012.55.7.485

Obstet Gynecol Sci > Volume 55(7); 2012 > Article

Original Article

Korean Journal of Obstetrics & Gynecology 2012;55(7):485-492.
DOI: https://doi.org/10.5468/KJOG.2012.55.7.485 Published online July 13, 2012.

Resistance of uterine radial artery blood flow is positively correlated with peripheral blood NK cell fraction in patients with unexplained recurrent spontaneous abortion.

Hwa Seon Koo, Hyun Jeong Yi, Min Young Lee, Hyun Suk Ahn, Min Hye Choi, Na Young Sung, Yu Im Hwang, In Ok Song, Mi Kyoung Koong, Inn Soo Kang, Kwang Moon Yang

Department of Obstetrics and Gynecology, Cheil General Hospital and Women's Healthcare Center, Kwandong University College of Medicine, Seoul, Korea. km1yang@naver.com

Abstract

OBJECTIVE
To evaluate whether increased peripheral blood inflammatory immune cell can induce decrease of uterine blood flow in patients with unexplained recurrent spontaneous abortion (RSA). METHODS: This study designed prospectively 33 pregnant women between 5 to 7 gestational weeks with a history of unexplained RSA included in this study. 47 normal pregnant women between 5 to 7 gestational weeks without history of infertility and/or RSA included as a control. Peripheral blood natural killer (pbNK) (CD3-/56+) fractions among peripheral blood monocyte (PBMC) were checked by flow cytometry. Uterine color-pulsed Doppler trans-vaginal ultrasound for evaluation of uterine radial artery RI was checked. Uterine radial artery resistance index (RI) compared between study and control group. After then, uterine radial artery RI was compared between high pbNK cell fraction above 12.1% among PBMC and normal pbNK cells fraction below 12.1%. Correlation between pbNK cell fraction to uterine radial artery RI was also evaluated. RESULTS: Uterine radial artery RI in early pregnancy was significantly higher in patients with RSA than that of normal control (0.60 +/- 0.14 vs. 0.54 +/- 0.12, P=0.039). Especially, the mean value of uterine radial artery RI in RSA patients with elevated pbNK cells was significantly increased than that of normal control (0.62 +/- 0.13 vs. 0.54 +/- 0.12, P=0.029). Otherwise, pbNK cell fractions among PBMC displayed strong positive correlation to uterine radial artery RI (Pearson's correlation coefficient P=0.001, r = 0.667). CONCLUSION: Increased pbNK cells can evoke decreased uterine blood flow by their pro-inflammatory action on micro vascular structure such as uterine radial artery. This can be a one causative mechanism of inducing spontaneous abortion by increased NK cells. But, larger scaled study is needed for clarify our results.

Key Words: Recurrent spontaneous abortion, Natural killer cell, Uterine radial artery resistance index