Kayo Tanaka
Mie University
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Featured researches published by Kayo Tanaka.
Journal of Obstetrics and Gynaecology Research | 2014
Hiroaki Tanaka; Kayo Tanaka; Chizuko Kamiya; Naoko Iwanaga; Jun Yoshimatsu
The incidence of Takayasu arteritis during child‐bearing years is relatively high. The management of pregnancies in patients with this disease is of great importance in clinical obstetrics. Here we analyzed pregnancies of women with Takayasu arteritis with and without complications.
Journal of Obstetrics and Gynaecology Research | 2015
Shinji Katsuragi; Kayo Tanaka; Takekazu Miyoshi; Chizuko Kamiya; Naoko Iwanaga; Reiko Neki; Jun C. Takahashi; Tomoaki Ikeda; Jun Yoshimatsu
Cesarean section is commonly selected in pregnancy with Moyamoya disease. We consider vaginal delivery with epidural anesthesia a viable alternative in such cases.
Circulation | 2016
Kayo Tanaka; Hiroaki Tanaka; Chizuko Kamiya; Shinji Katsuragi; Masami Sawada; Mitsuhiro Tsuritani; Masashi Yoshida; Naoko Iwanaga; Jun Yoshimatsu; Tomoaki Ikeda
BACKGROUND The effects of β-adrenergic blockers on the fetus are not well understood. We analyzed the maternal and neonatal outcomes of β-adrenergic blocker treatment during pregnancy to identify the risk of fetal growth restriction (FGR). METHODSANDRESULTS We retrospectively reviewed 158 pregnancies in women with cardiovascular disease at a single center. Maternal and neonatal outcomes were analyzed in 3 categories: the carvedilol (α/β-adrenergic blocker; α/β group, n=13); β-adrenergic blocker (β group, n=45), and control groups (n=100). Maternal outcome was not significantly different between the groups. FGR occurred in 1 patient (7%) in the α/β group, in 12 (26%) in the β group, and in 3 (3%) in the control group; there was a significant difference between the incidence of FGR between the β group and control group (P<0.05). The β group included propranolol (n=22), metoprolol (n=12), atenolol (n=6), and bisoprolol (n=5), and the individual incidence of FGR with these medications was 36%, 17%, 33%, and 0%, respectively. CONCLUSIONS As a group, β-adrenergic blockers were significantly associated with FGR, although the incidence of FGR varied with individual β-blocker. Carvedilol, an α/β-adrenergic blocker, had no association with FGR. More controlled studies are needed to fully establish such associations. (Circ J 2016; 80: 2221-2226).
Journal of Maternal-fetal & Neonatal Medicine | 2018
Shinji Katsuragi; Hiroaki Tanaka; Junichi Hasegawa; Masamitsu Nakamura; Naohiro Kanayama; Masahiko Nakata; Takeshi Murakoshi; Jun Yoshimatsu; Kazuhiro Osato; Kayo Tanaka; Akihiko Sekizawa; Isamu Ishiwata; Tomoaki Ikeda
Abstract Objective: The number of stroke-related maternal deaths is increasing in Japan. We investigated methods to reduce maternal death from stroke. Methods: We analyzed stroke-related maternal deaths in Japan reported to the Committee of the Ministry of Health, Labor, and Welfare from 2010 to 2014 inclusive. Results: A total of 35 cases were identified. The median maternal age was 35 years (range 22–45) and the incidence of stoke in women ≥40 was seven-fold higher than in <34. Etiologies were pregnancy induced hypertension in 16, subarachnoid hemorrhage in seven, cerebral infarction in three, arteriovenous malformation in two, Moyamoya disease in one, and origin unknown cerebral hemorrhage in six. These cases occurred in antepartum 43%, in postpartum 31%, and in intrapartum 26%. 23 cases were deemed non-preventable and 12 cases preventable. Possible preventable factors occurred antepartum in 23, postpartum in seven, and intrapartum in six. Preventable features included inadequate hypertension control (33%), presenting too late for termination of pregnancy (14%), delayed hospitalization (11%), and delayed maternal transfer (11%). Conclusions: A total of 90% of strokes were hemorrhagic, and older mothers (≥ 40) were most at risk. Most possible preventable factors occurred antepartum, and improved control of hypertension and earlier termination would help to reduce maternal death from stroke.
American Journal of Hypertension | 2018
Kento Yoshikawa; Takashi Umekawa; Shintaro Maki; Michiko Kubo; Masafumi Nii; Kayo Tanaka; Hiroaki Tanaka; Kazuhiro Osato; Yuki Kamimoto; Eiji Kondo; Kenji Ikemura; Masahiro Okuda; Kan Katayama; Takekazu Miyoshi; Hiroshi Hosoda; Ning Ma; Toshimichi Yoshida; Tomoaki Ikeda
BACKGROUND We investigated the efficacy and mechanisms of tadalafil, a selective phosphodiesterase 5 inhibitor, in treating preeclampsia (PE) with fetal growth restriction (FGR) using L-NG-nitroarginine methyl ester (L-NAME)-induced PE with FGR in pregnant mice as our experimental model. METHODS C57BL/6 mice were divided into 2 groups 11 days postcoitum (d.p.c.). A control group of dams (C dam) received 0.5% carboxymethylcellulose (CMC). A L-NAME-treated group received 1 mg/ml L-NAME dissolved in CMC. The L-NAME-treated dams were divided into 2 subgroups 13 d.p.c. One subgroup continued to receive L-NAME (L dams). The other subgroup received L-NAME with 0.08 mg/ml tadalafil suspended in CMC (TL dams). Maternal systolic blood pressure (SBP) and proteinuria were assessed 16 d.p.c. Fetal weight was recorded, and placentas and maternal kidneys were collected 17 d.p.c. RESULTS Maternal SBP, proteinuria, and fetal weight were improved for TL dams compared to L dams. The placental concentration of placental growth factor (PlGF) was higher for TL dams than for the C and L dams. The placental maternal blood sinuses of L dams were narrower than those of C dams, but those of TL dams improved to a similar width as C dams. Glomerular oxidative stress was ameliorated in TL dams compared to L dams. CONCLUSIONS Tadalafil dilates the placental maternal blood sinuses, which leads to increase PlGF production, and contributes to facilitate fetal growth and improve maternal SBP. Moreover, tadalafil ameliorates glomerular damage by reducing oxidative stress. These results suggest that tadalafil is a candidate for treatment of PE with FGR.
Journal of Maternal-fetal & Neonatal Medicine | 2016
Hiroaki Tanaka; Shinji Katsuragi; Kayo Tanaka; Masami Sawada; Naoko Iwanaga; Jun Yoshimatsu; Tomoaki Ikeda
Abstract Objective: Women during labor may be susceptible to torsades de pointes (TdP), which may cause the fetal condition to deteriorate. The aim of the present investigation was to analyze maternal and fetal outcomes during labor when long QT syndrome (LQTS) was present. Methods: We examined the maternal and neonatal outcomes of 25 pregnancies (18 women) with LQT between 1995 and 2012 at the Department of Perinatology, National Cardiovascular Center, Japan. Maternal and neonatal outcomes including cardiovascular events, cardiovascular events within a week after delivery, caesarean delivery rate, still births, preterm births, and non-reassuring fetal heart rate pattern (NRFHR) during labor were investigated. Results: All the mothers survived, and no cardiovascular events occurred in labor or postpartum due to LQTS in either vaginal delivery or caesarean delivery. A total of 23 women (92%) had used beta blockers in this study. Caesarean delivery was performed due to NRFHR during labor in 5 pregnancies (20%). Conclusion: Delivery when LQTS is present has a low likelihood of cardiovascular events, but pregnancy with LQTS had a higher caesarean delivery rate due to NRFHR in labor. Most women used beta blockers in this study, and it is possible that beta blocker use prevents cardiovascular events during labor. NRFHR during labor may be related with inherited LQT through the mother.
Journal of Obstetrics and Gynaecology Research | 2018
Shinji Katsuragi; Jun Yoshimatsu; Kayo Tanaka; Masafumi Nii; Takekazu Miyoshi; Reiko Neki; Kazunori Toyoda; Kazuyuki Nagatsuka; Jun Takahashi; Kenji Fukuda; Eika Hamano; Tetsu Satow; Susumu Miyamoto; Koji Iihara; Tomoaki Ikeda
We appreciate the interest and comments of Dr. Kumari and Dr. Bhatia on our article regarding the management of pregnancies complicated by intracranial arteriovenous malformation (iAVM). In the 36 cases we reported, 15 cases had no residual iAVM at conception, so these cases were not at risk for rebleeding. Regarding the angioarchitecture for the iAVM in the other 21 cases, the location of the iAVM was superficial in 13 and deep in 8 cases. The size of the iAVMs was small (<3 cm) in 15, medium (3~6 cm) in 4 and large (>6 cm) in 2 cases. One case had an associated arteriovenous fistula, and no cases had venous stenosis. In our case series, we did not perform endovascular embolism for the treatment of ruptured iAVM. If the nidus was in an operable position, and hemorrhage occurred in the first or second trimester, the nidus was removed, and the pregnancy continued. We decided on this mode of management after multidisciplinary team review because our surgical results for iAVMs are good. Our hospital is a specialized center for cerebrovascular diseases, and we operate a 24/7 service for cerebrovascular surgery. Surgical treatment made vaginal delivery possible in the index pregnancy in nearly all cases without fear of a rebleed. In one case, the nidus was located in the brain stem and was initially inoperable, and the patient had a hemorrhage in the second trimester. To reduce the risk of further bleeding during pregnancy, which could have been fatal for the mother, delivery was induced at 17 weeks, and subsequently, gamma knife radiosurgery was performed. We agree with Dr. Kumari et al. that endovascular embolism has a promising role in palliative as well as primary treatment in the management of iAVMs, including those diagnosed in association with pregnancy. We do use this technique if there are specific indications. As mentioned before, there are no consensus guidelines for the management of iAVMs in pregnancy, and therefore, the best management is likely to be that with which the center has the most expertise. As a result, such management will vary from center to center.
Journal of Obstetrics and Gynaecology Research | 2018
Shinji Katsuragi; Jun Yoshimatsu; Kayo Tanaka; Masafumi Nii; Takekazu Miyoshi; Reiko Neki; Kazunori Toyoda; Kazuyuki Nagatsuka; Jun Takahashi; Kenji Fukuda; Eika Hamano; Tetsu Satow; Susumu Miyamoto; Koji Iihara; Tomoaki Ikeda
To clarify the perinatal outcomes in pregnancy complicated with intracranial arteriovenous malformation (i‐AVM).
Journal of Maternal-fetal & Neonatal Medicine | 2018
Hiroaki Tanaka; Fumi H. Furuhashi; Kuniaki Toriyabe; Takeshi Matsumoto; Shoich Magawa; Masafumi Nii; Junko Watanabe; Kayo Tanaka; Takashi Umekawa; Yuki Kamimoto; Tomoaki Ikeda
Abstract Purpose: Fetal growth restriction (FGR) is a concerning health issue. However, studies on FGR management are limited due to its rarity. We aimed to evaluate the efficacy of the contraction stress test (CST) for FGR management. Materials and methods: A case-control retrospective study design. Our institute innovated CST in FGR management in 2017. We included women in their 33rd–40th week of pregnancy with a diagnosis of FGR and retrospectively divided them into groups: the CST group (FGR management with CST) and no CST group (FGR management without CST) before and after CST development. Neonatal outcome, pH, and pO2 of umbilical artery (UA) were compared between the two groups. Results: No significant differences in the rate of birth weight, Apgar score <7 (5 minutes), neonatal death, hospitalization to newborn childhood intensive care unit (NICU), and UA pH were found between groups. Average UA pH was 7.29 ± 0.05 and 7.29 ± 0.04 in the CST and no CST groups, respectively (p = .864). Average UA pO2 values were 21.1 ± 8.6 and 15.7 ± 5.0 mmHg in the CST and no CST groups, respectively (p = .016), showing significant differences. Conclusions: Neonatal outcomes and UA pH were slightly different between the groups managed with and without CST. However, UA pO2 values significantly differed between the groups. For FGR management, the use of a CST may allow for early intervention before fetal acidemia and acidosis. For establishing the effects of a CST for FGR management, analysis including several cases and investigation of long-term outcomes of newborn infants is necessary.
Journal of Maternal-fetal & Neonatal Medicine | 2018
Shinji Katsuragi; Hiroaki Tanaka; Junichi Hasegawa; Masamitsu Nakamura; Naohiro Kanayama; Masahiko Nakata; Takeshi Murakoshi; Jun Yoshimatsu; Kazuhiro Osato; Kayo Tanaka; Akihiko Sekizawa; Isamu Ishiwata; Tomoaki Ikeda; Gynecologists
Abstract Objective: Hypertensive disorder of pregnancy (HDP) is a major cause of maternal death. The goal of this study was to investigate factors associated with maternal death due to HDP. Study design: HDP-related maternal deaths in Japan reported to the Committee of the Ministry of Health, Labor and Welfare from 2010 to 2015 were examined. Results: Out of 47 cases of HDP, 30 were identified as the major cause of maternal death. The median maternal age was 34 years (range 24–45) and the mortality in women aged ≥40 years was seven times higher that than in women aged <34 years. The etiologies were intracerebral hemorrhage (n = 22), subarachnoid hemorrhage (n = 3), subcapsular hematoma of the liver (n = 2), peripartum cardiomyopathy (n = 2), and eclampsia (n = 1), and 19 cases were deemed preventable. The most frequent antepartum problems were delays in hospitalization, maternal transfer, and termination of pregnancy. In four cases, diagnosis of HELLP syndrome was too late because laboratory data were not checked, despite the patient reporting epigastric pain or showing elevation of blood pressure (BP). Treatment for lowering of BP was improper in 2/3 intrapartum cases, even though BP was elevated during pregnancy (144 versus 188 mmHg, p < .001). There was inadequate lowering of BP and lack of use of magnesium sulfate in 7/11 postpartum cases (64%), despite aspartate aminotransferase (AST) (p < .005), alanine aminotransferase (ALT) (p < .01), lactate dehydrogenase (LDH) (p < .005), and platelet count (PLT) (p < .01) all significantly worsening after delivery. Conclusion: HDP accounts for 11% of maternal deaths in Japan. Mothers aged ≥40 years are most at risk for HDP-related maternal death. Major concerns for preventabilities were late hospitalization, maternal transportation, and termination of pregnancy for term or near-term HDP. Regular vital checks and prompt lowering of BP were lacked during labor in most cases. HELLP syndrome should be managed at a general hospital with sufficient medical resources.