The Journal of Maternal-Fetal and Neonatal Medicine, 2013; 26(6): 576–580 © 2013 Informa UK, Ltd. ISSN 1476-7058 print/ISSN 1476-4954 online DOI: 10.3109/14767058.2012.745497
Cord blood oxidative stress markers correlate with umbilical artery pulsatility in fetal growth restriction Emine Seda Guvendag Guven1, Deniz Karcaaltincaba2, Omer Kandemir2, Sadiman Kiykac2 & Ahmet Mentese3 1Recep Tayyip Erdogan University, School of Medicine, Department of Obstetrics and Gynecology, Rize, Turkey, 2Etlik Zubeyde
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Hanım Women’s Health and Teaching Hospital, Ankara, Turkey, and 3Karadeniz Technical University, School of Medicine, Department of Biochemistry, Trabzon Turkey
Objective: To compare cord blood oxidative stress markers (OSM) between intrauterine small fetuses with high umbilical artery (UA) Doppler indices and normal indices. Methods: Forty women who had oligohydramnios and intrauterine growth-restricted fetuses with abnormal (n = 20, group I) or normal Doppler indices (n = 20, group II) were included. All patients underwent fetal Doppler ultrasound studies. Cord blood was collected at birth and six OSMs (ischemia-modified albumin (IMA), hepatocyte growth factor (HGF), malondialdehyde (MDA)) levels, total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) were studied. Results: The mean cord blood IMA, MDA, TOS, and OSI values for group I were significantly increased when compared to the group II (p < 0.001 for IMA, MDA, TOS, and OSI). However the mean cord blood HGF and TAS values were statistically significantly decreased in group I, compared with group II (p < 0.001 for HGF, and TAS). A significant positive (for IMA, MDA,TOS levels, and OSI ratio) and negative (for HGF and TAS levels) correlations between UA pulsatility index (PI) and cord blood OSM were found. Conclusion: The correlation between cord blood OSM and Doppler blood flow changes shown in this study may contribute to understanding the underlying oxidative stress-related mechanisms. Keywords: Cord blood, intrauterine growth restriction, ischemiamodified albumin, oxidative stress markers, pulsatility index, umbilical artery
Introduction Fetuses with intrauterine growth restriction (IUGR) are at increased risk for hypoxemia, acidemia, and adverse perinatal outcomes. Monitoring various parameters can give reliable and valuable information for determining the optimal time for delivery. However, in clinical practice only noninvasive parameters are of clinical value while frequent fetal monitoring is required in IUGR. The reduction of umbilical artery (UA) blood flow is an early finding in IUGR, and the reduction in blood flow is due to reduced umbilical velocity [1]. These Doppler changes may be due to the significant decrease in the number of functional trophoblasts. Elevated UA blood flow resistance is followed by a decrease in middle cerebral artery (MCA) impedance, an increase in venous Doppler indices, and a decline in amniotic fluid index (AFI). All these events lead to chronic fetal hypoxemia and if the fetus
remains undelivered, stillbirth may be the final outcome [2–4]. The relationship between abnormal fetal Doppler indices and the novel fetal oxidative stress markers (OSM) has not been well described in growth-restricted fetuses. Several markers of oxidative stress have been studied in intrauterine small fetuses, including prolidase activity, malondialdehyde (MDA) levels, total oxidant status (TOS), total antioxidant status (TAS), total free sulfhydryl, and oxidative stress index (OSI) [5]. Recently, it has been reported that the cord blood levels of new OSM (reactive oxygen intermediates, reduced glutathione, interleukin-6, 8-hydroxy-deoxyguanosine, redox factor-1, and hypoxia-induced factor-1α) were altered in intrauterine small fetuses [6–8]. In addition to these more established markers we selected ischemia-modified albumin (IMA) and hepatocyte growth factor (HGF) as novel markers of interest [5]. The IMA measured by the albumin cobalt binding test was used originally as a new marker of myocardial ischemia in the absence of myocardial necrosis [9]. IMA is regarded as a marker of oxidative stress related to ischemia since reperfusion in any organ rises within minutes from the onset of the ischemic event and remains elevated for several hours after cessation of ischemia [10]. HGF is a multifunctional protein secreted by both placenta and amniotic membranes into maternal circulation. The major sites for HGF production are the liver, kidneys, and pancreas in the fetus. HGF also plays a role in fetal growth, including liver regeneration, and placental development [11,12]. It may used as a marker of placental insufficiency. In this study, we aimed to combine the information regarding oxidative stress marker levels and noninvasive Doppler findings by comparing the OSM levels’ (IMA, HGF, MDA, TOS, TAS, and OSI) between intrauterine small fetuses with high Doppler indices (IUGR) and normal indices (SGA). In this way clinicians may noninvasively gain information on fetal oxidative status.
Materials and methods All consecutive patients admitted for further evaluation and management of small fetuses to our Women’s Health Teaching and Research Hospital in 1-year period were evaluated for study inclusion criteria. The ethics committee of our teaching hospital approved the study protocol. We carried out a standard initial approach (a detailed history of systemic diseases, obstetric complications–diabetes, hypertension, thyroid dysfunction, and so on etc.), smoking habits, medications,
Correspondence: Emine Seda Guvendag Guven, Recep Tayyip Erdogan University, School of Medicine, Department of Obstetrics and Gynecology, Rize, Turkey. Tel.: 090 (533) 233 98 54; Fax: 090 (312) 432 24 15. E-mail:
[email protected]
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Cord blood oxidative stress markers and IUGR a detailed fetal anatomical survey with ultrasonography, revisited fetal aneuploidy screening (combined first trimester test, triple test, fetal karyotype results), and a maternal serum evaluation for evidence of seroconversion if there were maternal or fetal signs suggestive of viral infection. We administered two intramuscular doses of betamethasone disodium phosphate 12 mg (Celestone chronodose 1 ml, 6 mg betamethasone; Schering-Plough, Istanbul, Turkey) within a 24-h interval for fetal lung maturation were administered for preterm gestations (to 12 women in group I, and 11 women in group II). All ultrasonographic examinations were performed by two of the authors (E.S.G.G. and D.K.) to confirm the gestational age using a GE Voluson 730 Pro (Indianapolis, IN, USA) ultrasound machine equipped with a 5-MHz abdominal probe. Free software for calculating customized fetal weight centiles based on fetal gender, maternal parity, ethnicity, height, weight, and age was used for this study (www.gestation.net). Serial ultrasonographic examinations at 2 weeks interval were performed for diagnosis of small fetus size. All small fetuses had birth weight less than the third percentile. The AFI was used for diagnosing oligohydramnios. The diagnosis of oligohydramnios was made when an AFI 2 SD below the mean for gestational age was considered as evidence of ‘brain sparing. UA and DV Doppler index elevation >2 SD above the mean for gestational age was considered elevated [3]. All patients in group II (n = 20, SGA) had small fetuses for gestational age and oligohydramnios and normal Doppler indices of UA, MCA, and DV. During patient selection procedure for group II, age and gestational age-matched consecutive controls were also selected for group I. After selection of 20 patients for each groups, patient selection procedure was commenced. Twenty of the women having intrauterine growth restricted fetuses with oligohydramnios (group I, IUGR) had elevated PI (above gestational age-related mean PI + 2 SD and/or A/REDV (UA absence (n = 4) or reversal of end diastolic velocities (n = 2)) on UA Doppler studies, and evidence of the “brain sparing effect” on MCA Doppler study (n = 4). However, all patients in group I had normal DV Doppler index studies. All pregnancy outcomes were obtained from the labor room database and checked by review of individual patient records. All neonates had no symptoms of intrauterine infection or stigmata of genetic syndromes. One- and five-minute Apgar scores were ≥8 and umbilical cord pH values were ≥7.25 in all cases. In all cases Doppler measurements and cord blood sampling were done on the same day. The time periods from Doppler measurements to cord blood sampling were 6.5 ± 2.2 h in group I and 6.3 ± 2.4 h in group II (p = 0.787). Exclusion criteria for the study were: (a) twin pregnancy; (b) a history of recurrent miscarriage; (c) any major or minor fetal anomaly; (d) current smoker; (e) having systemic disease; (f) having abnormal aneuploidy screening test results; (g) using © Informa UK, Ltd.
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medications other than multivitamin and antianemic drugs; and (h) refusal to participate. Blood was collected at birth from the doubly-clamped umbilical cord, reflecting the fetal state. In all case blood was collected from the UA: 5 ml of fetal blood into a nonheparinized tube, allowed to clot, centrifuged at 900g for 10 min, serum aspirated and stored at −80°C until analysis. The storage time for blood samples was below 8 months in all cases. The person performing the biochemical analysis was blinded to the groups and outcomes. Reduced cobalt to albumin-binding capacity (IMA level) was analyzed using the rapid and colorimetric method developed by Bar-Or et al. [14]. In our laboratory, the albumin-binding capacity assay within-run percent coefficient of variation (CV%) of patient samples averaged 2.1% [15]. IMA has a short half-life, returning to baseline values in 6–12 h [16]. Measurement of HGF concentration was performed using a commercially available Human HGF enzyme linked immunoassay kit (Catalog number # ELH-HGF-001; RayBiotech, Inc, Norcross GA, USA, Intra-Assay: CV
