Association between gestational age at delivery and lymphocyte-monocyte ratio in the routine second trimester complete blood cell count

Original article eISSN 2384-0293 Yeungnam Univ J Med 2021;38(1):34-38 https://doi.org/10.12701/yujm.2020.00234 Association between gestational age at delivery and lymphocyte-monocyte ratio in the routine second trimester complete blood cell count Hyun-Hwa Cha, Jong Mi Kim, Hyun Mi Kim, Mi Ju Kim, Gun Oh Chong, Won Joon Seong Department of Obstetrics and Gynecology, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea Received: March 31, 2020 Revised: May 26, 2020 Accepted: May 29, 2020 Corresponding author: Won Joon Seong Department of Obstetrics and Gynecology, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, 807 Hoguk-ro, Buk-gu, Daegu 41404, Korea Tel: +82-53-200-2686 Fax: +82-53-200-2086 E mail: Background: We aimed to determine whether routine second trimester complete blood cell (CBC) count parameters, including neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR), and platelet-lymphocyte ratio (PLR), could predict obstetric outcomes. Methods: We included singleton pregnancies for which the 50-g oral glucose tolerance test and CBC were routinely performed between 24 and 28 weeks of gestation in our outpatient clinic from January 2015 to December 2017. The subjects were divided into three groups according to their pregnancy outcomes as follows: group 1, spontaneous preterm births, including preterm labor and preterm premature rupture of membranes; group 2, indicated preterm birth due to maternal, fetal, or placental causes (hypertensive disorder, fetal growth restriction, or placental abruption); and group 3, term deliveries, regardless of the indication of delivery. We compared the CBC parameters using a bivariate correlation test. Results: The study included 356 pregnancies. Twenty-eight subjects were in group 1, 20 in group 2, and 308 in group 3. There were no significant differences between the three groups in neutrophil, monocyte, lymphocyte, and platelet counts. Although there was no significant difference in NLR, LMR, and PLR between the three groups, LMR showed a negative correlation with gestational age at delivery (r =−0.126, p =0.016). Conclusion: We found that a higher LMR in the second trimester was associated with decreased gestational age at delivery. CBC parameters in the second trimester of pregnancy could be used to predict adverse obstetric outcomes. Keywords: Blood cell count; Lymphocyte-monocyte ratio; Neutrophil-lymphocyte ratio; Preterm Introduction Preterm birth is a major cause of long-term morbidity and mortality in infants. Therefore, there have been many studies about the etiology and pathophysiology of preterm birth and methods for its early prediction and prevention. Complete blood cell (CBC) count parameters including neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR), and platelet-lymphocyte ratio (PLR) have been used for the detection of malignant diseases [1,2] or the prediction of prognosis in various diseases [3-5]. Meanwhile, in pregnant women, CBC for verifying hematocrit or hemoglobin is usually checked between 24–28 weeks during gestational diabetes mellitus (GDM) screening. Although CBC is not a good screening tool for pregnancy-associated diseases, it can provide valuable physiological information regarding pregnant women [6]. Labor is also Copyright © 2021 Yeungnam University College of Medicine This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. 34 https://doi.org/10.12701/yujm.2020.00234 Yeungnam Univ J Med 2021;38(1):34-38 an inflammatory response; therefore, CBC parameters could be used to predict preterm birth [7]. Recently, several studies have reported the association between CBC parameters and adverse obstetric outcomes such as GDM, hypertensive disorder, and preterm birth [8-12]. However, they were retrospective [8], case-control studies [10], or included cases after threatened preterm labor had developed [12]. This study aimed to determine whether routine second trimester CBC parameters during GDM screening could predict obstetric outcomes in pregnancy. Materials and methods This prospective observational study was conducted at the Kyungpook National University Hospital, Daegu, Korea, between January 2015 and December 2017 and approved by the Institutional Review Board of the Kyungpook National University Chilgok Hospital (IRB No: 2019-12-009). We included singleton pregnancies for which the 50-g oral glucose tolerance test (OGTT) and CBC count with differential count were routinely performed in the outpatient clinic between 24 and 28 weeks of gestation. Pregnant women were divided into three groups according to the pregnancy outcomes as follows: group 1 included preterm births due to preterm labor, preterm premature rupture of membranes (PPROM), or incompetent internal os of the cervix (IIOC). Preterm births were defined as births between 200/7 and 370/7 weeks of gestation. Preterm labor was defined as regular uterine contractions with a cervical change occurring at least three times every 10 minutes before 370/7 weeks of gestation. PPROM was defined as membrane rupture occurring spontaneously without labor before 370/7 weeks of gestation. IIOC was defined as painless cervical dilatation in the second trimester. Group 2 included preterm births due to maternal, fetal, or placental causes (hypertensive disorders including gestational hypertension and preeclampsia (PE), fetal growth restriction which was defined as the estimated fetal weight being suspected in the bottom 10 percentile at the corresponding gestational age, or placental abruption). Group 3 included term deliveries regardless of the indication of delivery. The exclusion criteria were as follows: multifetal gestation, gravidas who had diseases that could influence maternal CBC count levels, including malignant diseases, rheumatoid disorders, chronic hypertension, renal diseases, pregestational diabetes mellitus, or hematologic diseases. We compared CBC parameters between the three groups and evaluated the association of gestational age at delivery with CBC parameters using a bivariate correlation test. Statistical analyses were performed using the IBM SPSS version 19.0 (IBM Corp., Armonk, NY, USA) software. The results were considered statistically sighttps://doi.org/10.12701/yujm.2020.00234 nificant when the p-value was below 0.05. Results During the study period, 50-g OGTT and CBC were performed on 577 singleton pregnant women in our outpatient clinic. Among them, 221 did not deliver their babies at our institution. Consequently, we were able to include 356 singleton pregnancies. Forty-eight (13.5%) women delivered their babies before 370/7 weeks of gestation, with (...truncated)