ORIGINAL ARTICLE
Distinct temperament and character traits in patients with hyperemesis gravidarum
Erson Aksua, Yakup Albayrakb, Elmas Beyazy€uzb, Nihan Potasc, Ferit Durankus¸d, Burc¸ak Tenelb and Murat Beyazy€uzb
aDepartment of Gynecology and Obstetrics, Vatan Hospital, _Istanbul Rumeli University, _Istanbul, Turkey;bFaculty of Medicine, Department of Psychiatry, Tekirdag Namık Kemal University, Tekirdag, Turkey;cFaculty of Economics and Administrative Science, Department of Healthcare Managment, Ankara Hacıbayram Veli University, Ankara, Turkey;dDepartment of Pediatrics, G€oztepe Education and Research Hospital, _Istanbul Medeniyet University, _Istanbul, Turkey
ABSTRACT
Hyperemesis gravidarum (HG) is an extreme form of vomiting during pregnancy and is characterized with excessive vomiting and nausea and ketonuria, electrolyte imbalance, dehydration and severe nurtition deficiency. The etiology of HG is considered as multifactorial. Altough there is a great interest to HG in terms of psychiatric conditions, there have been limited numbers of studies that researched personality traits in patients with HG. In present study, we aimed to compare temperament and character traits between pregnant women with and without HG by Temperament and Character Inventory. 48 pregnant women with HG and 64 healthy pregnant women were included to study. The HG groups and control group were compared in terms of temperament and character traits and anxiety levels. The temperament scores of novelty seeking, harm avoidance and reward dependence were found to be similar between groups while the score of persistence was significantly lower in HG group compared with control group (p ¼ .021). All character scores in HG group as cooperativeness, self-directedness, and self-transcendence were significantly lower compared with control groups (respectively;p ¼ .002, p ¼ .018 and p ¼ .029). The scores of STAI-1 was higher in HG group compared with control group (p ¼ .027) whereas the score of STAI-2 was found to be similar between groups. Present study is the first to demonstrate different tem- perament and character traits in patients with HG. We argue that our results support the psychiatric back- ground of HG; however further studies are needed to confirm our results.
ARTICLE HISTORY Received 10 June 2019 Revised 26 August 2019 Accepted 20 October 2019 Published online 31 October 2019
KEYWORDS
Hyperemesis; personality;
character; temperament
Introduction
Hyperemesis gravidarum (HG) is an extreme form of vomiting during pregnancy and is characterized with excessive vomiting and nausea and ketonuria, electrolyte imbalance, dehydration and severe nurtition deficiency [1,2]. The prevalence of HG ranges between 0.03-3% based on diagnostic criteria and cultural and ethnic differences [3,4].The exact etiology of HG is not clear.
But the etiology of HG is considered as multifactorial.
Hormonal, genetic, enviromental and psychiatric factors were regarded as responsible factors in the etiology of HG [2–7].
Increased levels of human gonadotropic hormone, progesterone, estrogen and thyroid hormones were reported in patients who were suffering from HG [1,2]. Overactivation of sympathetic ner- vous system, altered lipid levels, hepatic abnormalities, infections and hepatic abnormalities were also considered as etiological fac- tors [2,8–12].
Beside the etiological factors that mentioned above, the psy- chological aspects of HG are not well established. Regarding anx- iety and depression, the studies reported conflicting results.
Several studies reported association between anxiety, depression and HG [13–15], however others resulted no connection [16,17].
The conflict of results that investigated psychiatric morbidity in HG can be associated with small sample sizes, retrospective design, lack of control groups of studies [3,12].
Although there is a great interest to HG in terms of psychi- atric conditions, there have been limited numbers of studies that researched personality traits in patients with HG. Uguz and his coworkers reported that prevalence of personality disorders were significantly higher in patients with HG compared with healthy pregnant women [5]. D’Orazio et al. reported no association between HG and personality characteristics which were obtained by Minnesota Multiphasic Personality Index [18]. However, there has been no current study that investigated personality traits in patients with HG such as Temperament and Character Inventory which was created by Cloninger [19].
In present study, we aimed to compare temperament and character traits between pregnant women with and without HG.
We hypothesized that patients with HG would differ in terms of temperament and character traits compared with pregnant women without HG.
Materials and methods
Present study was conducted at Tekirdag Namık Kemal University, Faculty of Medicine, Departments of Gynecology and Obstetrics and Psychiatry. The patients who were diagnosed with HG and hospitalized were screened for the study group. All patients were evaluated in terms of psychiatric diagnosis by a
CONTACT Yakup Albayrak dr.fuge@hotmail.com Faculty of Medicine, Department of Psychiatry, Namık Kemal €Universitesi Tıp Fak€ultesi, S€uleymanpas¸a, Tekirdag 59100, Turkey
ß 2019 Informa UK Limited, trading as Taylor & Francis Group https://doi.org/10.1080/09513590.2019.1683820
senior psychiatrist (YA). The inclusion criteria for HG group were as followings; diagnosed with HG, being willing to be par- ticipated into study, having enough education for understanding the aim of the study and the scales that would be used in study.
Having comorbid diseases, gestational problems such as immi- nent abortion, trophoblastic disease and ectopic pregnancy, hav- ing previous or past psychiatric diagnosis, tobacco and alcohol consumption and having multiple fetus were identified as exclu- sion criteria. According to inclusion and exclusion criteria 48 pregnant women with HG were participated into study.
Additionally age matched 64 healthy pregnant women were included to study as control group. All patients signed written informed consent after detailed explanation of study procedure.
The present study was approved by Tekirdag Namık Kemal University Noninvasive Clinic Research Ethical Committee.
Assessment tools
Sociodemographic and clinical form
This form was created by us in the light of literature. This form included the data of age, profession, education year, income, marriage duration, having a child and numbers of child.
Temperament and character inventory (TCI)
TCI is a 240-question self-evaluated questionnaire [19].
According to the Cloninger model, the temperament consisted of novelty seeking (NS) harm avoidance (HA), reward dependence (RD), and Persistence (P). The character includes the dimensions of self-directedness (SD), cooperativeness (CO) and self-tran- scendence (ST) [19]. The TCI was validated in Turkish in healthy and psychiatric Turkish populations [20].
State-Trait anxiety inventory (STAI-1 and STAI-2)
STAI includes 20 items measuring state-anxiety (STAI-1) and 20 items of trait anxiety (STAI-2). Trait anxiety was measured at baseline, and state anxiety was measured at follow-up. High con- current validity was found between the State-Trait Anxiety Inventory and other scales that measure anxiety, with correlation ranging from 0.73 to 0.85 [21].
Statistical analysis
Statistical analyses were performed with R 3.5.1, GPower 3.1, STATA 14.1 and SPSS 23.0. For the mean’s comparisons inde- pendent sample t-test was used. For its assumptions, the Kolmogorov-Smirnov test was used to test for normality accord- ing to the categories and for the variance homogeneity, Levene test was used. Otherwise, Mann–Whitney U test was used to determine the differences.
To determine the differences between groups when the response consists of two or more potentially interrelated varia- bles, multivariate analysis of variance can be used. If the assump- tions are provided (Normality, Variances Homogeneity etc.), the parametric test is the perfect way to determine the differences. If not provided; PERMANOVA can be used, that is distance-based multivariate analysis of variance, also known as nonparametric MANOVA. According to that, the multivariate normality was not provided so the non-parametric test was performed.
We would like to examine the differences between the patient and control groups, when the novelty seeking (NS) harm avoid- ance (HA), reward dependence (RD), Persistence (P) and the self-directedness (SD), cooperativeness (C), self-transcendence (ST). Also in the first model, STAI 2 effects and interactions with group also investigated. in the second model, having child, profession and STAI 2 effects and interactions (Group STAI-2, Have Child STAI-2, Group Have Child and Group Have Child STAI-2) also examined.
We would like to use multiple regression to understand whether STAI-2 score can be predicted based on some variables likewise the novelty seeking (NS), harm avoidance (HA), reward dependence (RD), Persistence (P) and the self-directedness (SD), cooperativeness (C), self-transcendence (ST). However, we only find that the cooperativeness (C) and the novelty seeking (NS) can predict STAI-2 score. After fitting the regression model, the residuals (errors) distribution examined for the normally. The homoscedasticity, multicollinearity and the independence of residuals was also investigated. Normal distribution of the resid- uals (errors), homoscedasticity, multicollinearity and the inde- pendence of residuals were examined. Independence of residuals was tested by Durbin–Watson statistics (D–W ¼ 2.302). The multicollinearity was evaluated by using Pearson correlations (.201 < q < .255) and collinearity statistics (Both of VIF¼ 1.042). The normality assumption can be tested by looking at the P-P plot and the assumption of homoscedasticity can be checked by scatter-plot for the model. So, some plots were used as 3 D- scatterplot and Normal Q-Q Plot for its assumptions. Power ana- lysis was also performed to calculate the power of the study.
Power analysis
Power analysis is a very important role in research. According to its role, we calculate our sample size with two different analysis.
Firstly, independent samplet-test statistic was used as test statis- tic for power analysis. The results of the power analysis showed that group sample sizes of 48 and 64 (total sample size ¼ 112) achieved 88.49% power to detect a difference of2.95. Secondly, multiple linear regression was used. The results of multiple regressions with effect size 0.12 showed that at n ¼ 100, the power of the test has already %94. From the two way calculation of the power showed that the sample size of the study can be determined as n ¼ 112 and there would not be loss of power (Figure 1).
Results
The mean ages in HG and control were 27.60 ± 5.95 years and 29.70 ± 5.18 years respectively. The groups were similar in terms of age. The groups were also similar in terms of education status, marriage year, having a child, numbers of child and job sta- tus (p > .05)
The scores of TCI were compared between groups. The tem- perament scores of NS, HA, RD were found to be similar between groups while the score of P was significantly lower in HG group compared with control group (p ¼ .021). Among char- acter scores, all scores in HG group as C, SD and ST were sig- nificantly lower compared with control groups (respectively;
p ¼ .002, p ¼ .018 and p ¼ .029). The scores of STAI-1 was higher in HG group compared with control group (p ¼ .027) whereas the score of STAI-2 was found to be similar between groups (Table 1).
We investigated the effects of other variables on TCI scores.
Several assumptions are required for the multivariate analysis of variance (MANOVA). PERMANOVA was applied because the assumption of the multivariate normality was not provided. In the first model, those spatial effects were the strongest in the two-way interaction (group and STAI-2). STAI- 2, although stat- istically significant (p < .05), was less important than any of the spatial factors. Statistically, model 1 was significant (F(3,108) ¼ 6.3103; p ¼ .001). In the second model, group and two- way interaction of group and STAI-2 and three-way interaction of having a child, group and STAI-2 were the strongest effect size.
Although there was no evidence for a two-way interaction (group have child; p > .05), effects of having a child varied across the group (have child and group; p < .05). Have child,
profession, STAI- 2, have child STAI- 2, although statistically significant (p < .05), was less important than any of the spatial factors (Table 2). Model 2 was statistically significant as well (F(8,103)¼ 4.7966; p ¼ .001).
Multiple regression, assumptions were also examined. Normal distribution of the residuals (errors), homoscedasticity, multicol- linearity and the independence of residuals were examined. A multiple linear regression was calculated to predict STAI-2 based on cooperativeness (C) and novelty seeking (NS). The model is significant at 5% significance level (F(2,109) ¼ 6.752; p ¼ .002).
Patients’ predicted STAI-2¼ 35.726 þ 0.456(C) þ 0.376(NS), where (C) is measured from the character, and (NS) is measured from the novelty seeking. Patients’ STAI-2 scores increased 0.46 for each score of (C) and 0.38 for each score of (NS). According to the Table 3 in the first model explains approximately 11% of the change in STAI-2. C and NS had statistically significant effect on STAI- 2 (Table 3).
Discussion
In present study, the major findings were as followings; all char- acter scores including cooperativeness, self-directedness and self- transcendence and persistence which is one of temperament score were significantly lower in HG group compared with con- trol group. Additionally, we found that scores of cooperativeness and novelty seeking had statistically significant effects on STA-2
10 20 30 40 50 60 70 80 90 100 110 120
0 0,2 0,4 0,6 0,8
Power (1-β err prob)
0,162 0,317
0,459 0,581
0,683 0,763
0,826 0,874 0,910 0,936 0,955 0,969
= 0,05 α err prob t tests - Linear multiple regression: Fixed model, single regression coefficient
Tail(s) = Two, Number of predictors = 2, Ef fect size f ² = 0,123595, α err prob = 0,05
Total sample size Figure 1. Power analysis of study.
Table 1. Comparison of TCI and STAI-1 and STAI-2 scores between groups.
Group n x±s p-value
NS
Patient (HG) 48 20.90 ± 4.759 .107
Control 64 19.58 ± 3.808
HA
Patient (HG) 48 57.72 .059
Control 64 55.59
RD
Patient (HG) 48 10.56 ± 2.782 .076
Control 64 11.39 ± 2.113
P Patient (HG) 48 48.45 .021
Control 64 62.54
SD
Patient (HG) 48 20.63 ± 6.380 .018
Control 64 23.16 ± 3.937
C
Patient (HG) 48 16.69 ± 5.555 .002
Control 64 19.64 ± 3.835
ST
Patient (HG) 48 12.04 ± 4.356 .029
Control 64 13.80 ± 4.005
STAI-1
Patient (HG) 48 64.33 .027
Control 64 50.63
STAI-2
Patient (HG) 48 50.64 ± 6.278 .197
Control 64 52.47 ± 8.120
C: cooperativeness; HA: harm avoidance; MADRS: Montgomery-Åsberg Depression Rating Scale NS: novelty seeking, RD: reward dependence; P: persist- ence, SD: self-directedness; ST: self-transcendence, STAI: State-Trait Anxiety Inventory TCI: Temperament and Character Inventory.
Significantp values were indicated as bold characters.
Mann–Whitney U test.
Student T test.
Table 2. Permutational analysis of variance (PERMANOVA) results.
Factors df SS R2 Pseudo-F p-value
Group 1 0.0261 0.0469 5.954 .001
STAI 2 1 0.0238 0.0428 5.439 .005
Group STAI 2 1 0.0331 0.0593 7.529 .003
Residual 108 0.4736 0.8508
Total 111 0.5567 1.00
Group 1 0.0261 0.0469 6.631 .001
Have Child 1 0.0109 0.0197 2.787 .034
Profession 1 0.0143 0.0258 3.643 .005
STAI-2 1 0.0185 0.0332 4.689 .009
Group STAI-2 1 0.0297 0.0534 7.556 .003
Have Child STAI-2 1 0.0159 0.0286 4.051 .019
Group Have Child 1 0.0059 0.0106 1.507 .207
Group Have Child STAI-2 1 0.0296 0.0531 7.509 .006
Residual 103 0.4055 0.7286
Total 111 0.5567 1.00
STAI: State-Trait Anxiety Inventory.
Significantp values were indicated as bold characters. SS: Sums-of- squares.
in multiple regression analysis. Having a child, score of STAI-2 having a job had statistical effects on TCI scores in PERMENOVA analysis.
The Cloninger’s personality model has been considered as psychobiological approach to the personality model divides per- sonality into two parts as temperament and character. According to this model, temperament is considered as a hereditary and stable; while character is regarded as some traits that are created under the impact of environment and the choices of individual.
Thus, personality is summary of temperament and character [22–24]. Temperament and character are not absolute rigid structures and can differ with some medical and psychosocial conditions. TCI was not only used in psychiatric conditions; it has been widely used in various psychosomatic conditions [25,26]. However, there has been not any study which investi- gated temperament and character traits in patients with HG.
Our results indicated that patients with HG had different character traits compared with healthy pregnant women. Firstly, HG patients scored significantly lower in cooperativeness score than controls. People who have higher cooperativeness scores are defined as empathetic, tolerant, compassionate, supportive, fair, and principled individuals. They tend to be a good partner in teamwork as well as other areas of life. In contrast, lower scores of cooperativeness score indicate that decreased empathy and also can have communication problems with other [22,23]. HG patients also scored significantly lower on SD dimension com- pared with controls. People who are high on SD are certain of their purposes. They tend to accept responsibility for their atti- tudes and behavior. In contrast clinicians commonly define peo- ple who have lower scores on SD as having a personality disorder. HG patients had also lower scores on self-transcend- ence dimension. Self-transcendent people are defined as satisfied, patient, creative and spiritual. These individuals seem to tolerate ambiguity and uncertainty. High Self-Transcendence has adaptive advantages when a person is confronted with suffering and death, which is inevitable with advancing age. In contrast lower scores on ST attributes that tend to intolerate uncertainty and ambiguity [22–24]. We can say that HG patients globally differ- ent character traits compared with healthy pregnant women. Our
result is the first to demonstrate different character traits in patients with HG.
Regarding temperament dimension, patients with HG had sig- nificantly lower score of persistence compared with healthy preg- nant women. People who are high in persistence tend to be industrious, persistent, and stable despite frustration and fatigue.
People who had lower persistence score are described as unchal- lenged, fatigue and unstable [22–24]. Pregnant women with and without HG were found to have similar scores on other tempera- ment scores as novelty seeking, harm avoidence and reward dependence. This finding is also first to describe different tem- perament trait in literature.
The psychiatric background of HG can be considered to be conflicted. Current studies that investigated this issue regarded development of depression, anxiety or other psychiatric disorders or symptoms during HG as results of HG rather than a cause [3,17,18]. However, a relatively recent meta-analysis which inves- tigated psychological status in patients with HG reported that anxiety scores had a large effect in women with HG and signifi- cant heterogeneity was detected in terms of depression and anx- iety [27]. Although our results indicated there have been some factors such as having a child, anxiety status effected the TCI scores, we argue that our results are challenging for demonstrat- ing the psychiatric background of HG based on the knowledge of more stability of personality traits compared with other psy- chiatric symptoms. Furthermore, we found that some TCI dimensions such as novelty seeking and cooperativeness effected the trait anxiety level in patients with HG.
There have been several studies which investigated tempera- ment and character traits and their associations with some psy- chiatric symptoms during pregnancy. Takegata et al. reported that low self-directedness and low co-operativeness were related to self-harm, anxiety and depression in pregnant women [28].
Morisaki et al. found that some parental personality traits could affect birth outcomes [29]. Another study showed that smokers with higher self-directedness and lower harm avoidance were more likely to abstain during pregnancy [30]. Moreover, there have been studies which investigated affective temperaments in pregnant women. Yazıcı et al. reported that cyclothymic, irritable and anxious temperament scores of the pregnant women were
Table 3. The results of multiple linear regression between STAI-2 scores and scores of C and NS and the scatter plot between scores STAI-2, C and NS.
Model
STAI-2
B t p
Constant 35.726 7.819 .000
C 0.456 3.239 .002
NS 0.376 2.351 .021
R2 0.110
F 6.753
p-value .002
C: Cooperativeness; NS: Novelty Seeking; STAI: State-Trait Anxiety Inventory.
significantly lower compared with non-pregnant ones [31].
Again, Yazıcı et al. investigated affective temperament during pregnancy and they concluded that pregnancy and postpartum periods correlated with hyperthymic temperament characteristics in women without active psychiatric diagnosis. [32]. In our study, we took into account that pregnancy would change per- sonality traits and we did not include a non-pregnant group for overwhelming the possible confounding results.
While we regard the global meaning of results of present study, it can be said that patients with HG apparently had differ- ent personality traits compared with healthy pregnant women.
Even psychiatric symptoms were considered as result of the clin- ical symptoms of HG by several studies [1,3,18], our study dem- onstrated that HG patients had several personality traits which can be associated with tendency to psychiatric symptoms. Thus, we suggest that patients with HG should be consulted with psychiatry in terms of supporting the treatment.
Strengths of our study are followings; first to describe tem- perament and character traits in patients with HG, excluding patients who had psychiatric disorders and evaluation of patients by senior psychiatrist (YA). Although we made power analysis for present study, the sample sizes may be regarded as small for making a general conclusion. The anxiety status, being pregnant, age and educational status may effect reliability of TCI nega- tively. These issues may be regarded as limitation. However, the groups were similar in terms of these confounding effects. Other issue is bias; this study was not a randomized research; during analysis all participants were numbered and the statistician was blind to participants; however it can be also considered as a limi- tation. We did not include non-pregnant women in present study for avoiding confounding effects of pregnancy on TCI; this issue can be accepted as both strength and limitation.
Conclusion
In conclusion, present study is the first to demonstrate different temperament and character traits in patients with HG. We argue that our results support the psychiatric background of HG. In clinical practice, we think that patients with HG should be eval- uated by psychiatry for supporting the treatment management.
Further studies are needed to confirm our results.
Disclosure statement
The authors have no conflicts of interest.
References
[1] Ismail SK, Kenny L. Review on hyperemesis gravidarum. Best Pract Res Clin Gastroenterol. 2007;21(5):755–769.
[2] Verberg MF, Gillott DJ, Al-Fardan N, et al. Hyperemesis gravidarum, a literature review. Hum Reprod Update. 2005;11(5):527–539.
[3] London V, Grube S, Sherer DM, et al. Hyperemesis gravidarum: a review of recent literature. Pharmacology. 2017;100(3-4):161–171.
[4] American College of Obstetricians and Gynecologists. Practice Bulletin No. 153: nausea and vomiting of pregnancy. Obstet Gynecol.
2015;126:e12–e24.
[5] Uguz F, Gezginc K, Kayhan F, et al. Is hyperemesis gravidarum asso- ciated with mood, anxiety and personality disorders: a case–control study. Gen Hosp Psychiatry. 2012;34(4):398–402.
[6] Tan PC, Vani S, Lim BK, et al. Anxiety and depression in hypereme- sis gravidarum: prevalence, risk factors and correlation with clinical severity. Eur J Obstet Gynecol Reprod Biol. 2010;149(2):153–158.
[7] Hendler I, Blackwell SC, Treadwell MC, et al. Does advanced ultra- sound equipment improve the adequacy of ultrasound visualization
of fetal cardiac structures in the obese gravid woman? Am J Obstet Gynecol. 2004;190(6):1616–1619.
[8] Niemeijer MN, Grooten IJ, Vos N, et al. Diagnostic markers for hyperemesis gravidarum: a systematic review and metaanalysis. Am J Obstet Gynecol. 2014;211:150.e1–150.e15.
[9] Ust€un Y, Engin-Ust€un Y, D€okmeci F, et al. Serum concentrations of lipids and apolipoproteins in normal and hyperemetic pregnancies. J Matern Fetal Neonatal Med. 2004;15:287–290.
[10] Koch KL. Gastrointestinal factors in nausea and vomiting of preg- nancy. Am J Obstet Gynecol. 2002;186:198–203.
[11] Lee RH, Pan VL, Wing DA. The prevalence ofHelicobacter pylori in the Hispanic population affected by hyperemesis gravidarum. Am J Obstet Gynecol. 2005;193(3):1024–1027.
[12] Aksoy H, Aksoy €U, Karadag €O_I, et al. Depression levels in patients with hyperemesis gravidarum: a prospective case-control study.
Springerplus. 2015;24(4):34.
[13] Swallow BL, Lindow SW, Masson EA, et al. Psychological health in early pregnancy: relationship with nausea and vomiting. J Obstet Gynaecol. 2004;24(1):28–32.
[14] Bozzo P, Einarson TR, Koren G, et al. Nausea and vomiting of preg- nancy (NVP) and depression: cause or effect? Clin Invest Med. 2011;
34(4):245.
[15] Yıldırım E, Demir E. The relationship of hyperemesis gravidarum with sleep disorders, anxiety and depression. J Obstet Gynaecol. 2019;
15:1–6.
[16] Kjeldgaard HK, Eberhard-Gran M, Benth JS, et al. History of depres- sion and risk of hyperemesis gravidarum: a population-based cohort study. Arch Womens Ment Health. 2017;20(3):397–404.
[17] Christodoulou-Smith J, Gold JI, Romero R, et al. Posttraumatic stress symptoms following pregnancy complicated by hyperemesis gravida- rum. J Matern Fetal Neonatal Med. 2011;24(11):1307–1311.
[18] D’Orazio LM1, Meyerowitz BE, Korst LM, et al. Evidence against a link between hyperemesis gravidarum and personality characteristics from an ethnically diverse sample of pregnant women: a pilot study. J Womens Health (Larchmt). 2011;20:137–144.
[19] Cloninger CR. A systematic method for clinical description and clas- sification of personality variants. Arch Gen Psychiatry. 1987;44(6):
573.
[20] Kose S, Sayar K, Kalelioglu U, et al. Normative data and factorial structure of the Turkish version of the temperament and character inventory. Compr Psychiatry. 2009;50(4):361–368.
[21] Spielberger CD. State–trait anxiety inventory for adults. Sampler set, manual set, scoring key. Palo Alto CA: Consulting Psychologists Press; 1983.
[22] Cloninger RC, Svrakic DM, Przybeck T. A psychobiological model of temperament and character. Arch Gen Psychiatry. 1993;50(12):
975–990.
[23] Cloninger CR, Przybeck TR, Svrakic DM, et al. Applications to mood disorders. In: The temperament and character inventory (TCI): a guide to its development and use, Cloninger CR (Ed), St. Louis, MO:
Center for Psychobiology of Personality, Washington University;
1994.
[24] Kose S. A psychobiological model of temperament and character:
TCI. Yeni Symposium. 2003;41:86–97.
[25] Fava GA, Cosci F, Sonino N. Current psychosomatic practice.
Psychother Psychosom. 2017;86(1):13–30.
[26] Cosci F. Assessment of personality in psychosomatic medicine: cur- rent concepts. Adv Psychosom Med. 2012;32:133–159.
[27] Mitchell-Jones N, Gallos I, Farren J, et al. Psychological morbidity associated with hyperemesis gravidarum: a systematic review and meta-analysis. BJOG. 2017;124(1):20–30.
[28] Takegata M, Takeda S, Sakanashi K, et al. Perinatal self-report of thoughts of self-harm, depressive symptoms, and personality traits: a prospective study of Japanese community women. Psychiatry Clin Neurosci. 2019. [Epub ahead of print].
[29] Morisaki N, Fujiwara T, Horikawa R. The impact of parental person- ality on birth outcomes: a prospective cohort study. PLoS One. 2016;
22(11):e0157080.
[30] Massey SH, Reiss D, Neiderhiser JM, et al. Maternal personality traits associated with patterns of prenatal smoking and exposure: implica- tions for etiologic and prevention research. Neurotoxicol Teratol.
2016;53:48–54.
[31] Yazici E, Terzi H, Bosgelmez S, et al. Effective temperaments in preg- nancy. Gynecol Endocrinol. 2014;30(12):894–898.
[32] Yazici E, Uslu Yuvaci H, Yazici AB, et al. Affective temperaments during pregnancy and postpartum period: a click to hyperthymic temperament. Gynecol Endocrinol. 2018;34(3):265–269.
