Document Type : Review Article
Authors
1 PhD Student in Reproductive Health, Department of Midwifery, School of Nursing and Midwifery, Mashhad University of Medical Sciences, Mashhad, Iran
2 a) Professor, Nursing and Midwifery, Mashhad University of Medical Sciences, Mashhad, Iran b) Department of Midwifery, Faculty of Nursing and Midwifery, Mashhad University Medical of Medical Sciences, Mashhad, Iran
Abstract
Keywords
Introduction
In many cultures, childbearing is considered as one of the functions of the family, and infertility is considered unpleasant (1). In a study conducted at the International Health Institute in Belgium, France and the Netherlands, infertile women were ranked fourth in terms of the severity of stress among life-stressful experiences after maternal death, father death and infidelity from the list of 12 influential vital events. Infertility rates in different countries vary from 5% in some developed countries to more than 35% in sub-Saharan Africa. In Iran, more than 1.5 million couples (2013) face infertility problems (1).
Along with the significant advancement of medical knowledge in the use of assisted reproductive techniques (ART) and the welcome of infertile couples from this new technology, numerous issues in various legal, religious and moral fields have emerged (2). One of these methods is to donate gametes and embryos to infertile couples under certain conditions (3). The use of donation in assisted reproduction techniques, as much as it can be responsible for the problems caused by not having children in families, if be not legal, it can cause many disorders in the society. The donation method requires the addition of a person outside the family (third person) to help the fertility of the family, and the entry of a person from outside the family, itself causes many problems in psychological, jurisprudential, moral and legal dimensions (4). In many parts of the world, embryo donation is an accepted method for infertile couples. For example, in the United States, Australia, European countries such as Belgium, Greece, Russia, Spain and the United Kingdom, this method is commonly used (4).
Embryo donation is a type of third reproduction in which the embryo resulted from in vitro fertilization (IVF) is donated to another couple. If other methods of assisted reproduction are unsuccessful, the doctor may recommend the donated embryo to the couple (5). Embryo donation has legal status in Iran under certain conditions (6). Iran is one of the few Islamic countries where donations including eggs, sperm and embryos along with payment to the donor are accepted based on the imitators' authorities; according to the law approved by the Islamic Consultative Assembly, embryo donation can be done (7).
Latifnejad Roudsari (2013) showed that couples' religious beliefs, especially women's beliefs, do not affect their negative attitude towards fertility donation methods. The importance of childbearing for women makes them less influenced by their beliefs. However, the positive view of most Islamic jurists in Iran is also helpful (8). In Iran, after the necessary studies, especially after the seminar on legal issues of embryo transfer in 1998, the law on how to donate embryos to infertile couples was approved by the Islamic Consultative Assembly on 2003 and a change was made in this regard. The executive regulations of this law were also approved and published in 2004 (9). According to this regulation, embryo donors must have a marriage-based relationship, be physically and mentally healthy, have an appropriate IQ, not be addicted to addictive substances and psychedelics, and don't have incurable diseases (AIDS and hepatitis) (10).
Embryo donation means the transfer of genetic, cultural and social heritage of the donor family to the offspring, and can have many consequences, so proper education and information on various aspects of the issue is essential for donor and recipient couples (11). Infertile couples face many challenges in choosing a donor that will put a lot of pressure on them. Latifnejad Roudsari (2013) in a qualitative study on couples using donation methods reported that the majority of couples agreed with the stranger donor and their most important criterion was moral character. However, due to the limited number of donors, the majority of couples chose the donor without considering it and without any research on the donor (12).
With the tendency to treat infertility with third-party fertility method, it has provided the basis for numerous religious questions and the need for planning in using these methods in legal dimensions. The careful attention of some donors and recipients to the sharia concerns in alternative fertility and the observance of its rules is one of the important issues in the donation process and the legal aspects of this process should be clear with the written instructions and laws (7). Infertility counseling is for discovering, understanding and solving the problems caused by infertility and treating infertility and clarifying the ways to deal with the problem. The purpose of counseling is to provide services to patients, emotional support in times of crisis and help them by choosing their treatment method and its impact on their life (13).
However, providing specialized counseling, including providing information, understanding information and supporting people in the face of the consequences of the use of medical methods in order to achieve the principle of respect for the individual independence of applicants is necessary and this requires the presence of a trained and skilled counselor (14). In the study by Yahyaee (2016), it was reported that providers of embryo donation services in infertility treatment centers have provided only brief information about the medical aspects of the embryo donation process to applicants. Despite the requirement of many governments to provide accurate advice on donating embryos to donation parties, some physicians ignore the need for providing the specialized advice (15).
Also in the study of Yahyaee (2016), it was reported that the organization of specialized counseling sessions for infertile couples is limited to infertility treatment centers and even advice to consult with specialists has been given in a few cases, and at the same time a small number of people (11%) have acted on this recommendation. Also, most people (81%) stated that embryo donation service providers in infertility treatment centers didn’t emphasize on the need for legal and jurisprudential counselling in this area, and on the other hand, one of the infertility treatment centers has explicitly stated that medical centers are not responsible for providing specialized legal and jurisprudential counselling (15).
Since the laws, rights and religion of individuals in each country are unique in this regard, it is necessary for health care providers in the infertility team to provide the necessary knowledge about the legal aspects (lineage, inheritance, marriage, alimony, custody and citizenship), legal (donor and recipient-specific conditions), ethical and jurisprudential (legal permission) in consultation sessions before embryo donation to reduce potential problems, for example in French law, a relatively comprehensive regulation about donation or, in the words of French law, "third party donor intervention" is predicted (5). Therefore, the present review study was conducted to review the legal, jurisprudential, ethical and advisory aspects of embryo donation in Iran.
Materials and Methods
This review study is the result of reviewing the published evidence on the legal, jurisprudential and ethical aspects of embryo donation by Iranian authors without time limitation in SID, CINAHL, Google Scholar and Iran Medex, Scopus and PubMed databases. To collect information, at first the articles that in the title or text had one of the words of donated embryo, pregnancy with third party participation, infertility, law, jurisprudence, ethics and Iran alone or in combination as Persian and English equivalents were searched. A total of 50 articles were obtained from PubMed, 35 from Scopus, 58 from google Scholer, 30 from SID and 4 from Iran Medex databases.
Deleting 87 articles by reviewing the title and abstract of duplicate and overlapping articles.
Inclusion criteria were: publication of an article on legal, jurisprudence, ethics or consulting issues published by Iranian authors in Persian or English. Exclusion criteria were: the content out of the study and expressing the individuals' experience or views, letter to the editor and abstracts of conference, which by eliminating duplicates, finally 39 articles which met the inclusion criteria were reviewed. At first, the first author studied the study sections separately and recorded his impression in each section. The points extracted from all the articles in the field of law, jurisprudence and ethics of embryo donation were re-evaluated by the second researcher.
Results
Legal documents
In legal discussions, one of the first issues that has received a lot of attention is the specific conditions of embryo donors and recipients, which are as follows in the law of the Islamic Republic: Embryo donors are divided into 3 groups: The first group includes the couples who are fertile themselves and have normal reproduction but undergo IVF treatment to produce the fetus and donate it to others; the second group includes the couples who are infertile and are receiving IVF treatment and after pregnancy by others' embryos and the assurance of having child, the extra formed embryos which were donated to them returned to medical centers; the third group also includes those couples who are infertile and after treatment through their own sexual cells, additional embryos produced from their sexual cells are donated to medical centers.
According to Article 1 of the Law and Article 2 of the By-Laws, donors must have: Normal physical and mental health, an appropriate IQ, no addiction and no incurable transmitted diseases. The important thing is that the conditions of the donors are much more important than the recipients. In Iranian law, there are 4 conditions: a) Impossibility of fertility and the ability to receive the fetus, which according to paragraph 2 of the law, this condition must be approved by the court. b) Moral competence. c) Legal competence. d) Iranian citizenship (16).
Another important issue in the law on embryo donation is the issue of confidentiality in the disclosure of the identity of donors. In the discussion of anonymous donation of gametes or embryos, countries are divided into two categories: some countries, including Canada, USA, Belgium and France, have considered anonymous donation as legal, and some including Britain, Sweden and Netherlands have considered it illegal. Reasons for opposing confidentiality in gamete or embryo donation include: the right of child to know, the need to be aware of the child's background, prevention of incest, and the reasons for it's agreement are as follows: insignificance of genetic relationships for individuals, supporting the child and his parents, creating a unified educational system for the child (17).
Azimzadeh Ardabili (2011) in his article stated that about the confidentiality of embryo donation and the necessity of not disclosing the names of donors, the law is silent and this rule is stated in the executive regulations of the law (14). Hashemi (2007) in this regard states that the anonymity of donor couples will cause less legal and emotional interactions in the future for the donor and recipient couples. On the other hand, the human rights of children born in this way require that they be informed of how they were born. Also, the possibility of unintentional incest and genetic abnormalities following an increase in the number of deliveries by assisted reproduction, in general, lead to the idea of telling the truth to children, especially before puberty. It also seems that the information of the applicant couples regarding the medical and legal issues of embryo donation is not sufficient and it is necessary to provide facilities for information and specialized consultations before taking action (6).
In confirmation of this issue, Mohammadi (2010) and Alavi Qazvini (2018) also in their articles stated that in Iranian law, the feature of secrecy for legal institutions cannot be accepted and in fact to avoid any mixing of genealogy, inheritance corruption as well as the prevention of incestuous marriages and the severance of mercy, which are the rules of many Shari'a rulings, it is necessary to keep information about the genetic identity of the children born from the donation, like other children of one person, in the registry offices and access to them must be subject to the registration information (2,18).
Legal effects of embryo donation
Issues related to the legal aspects of embryo donation in the fields of lineage, inheritance, marriage, alimony, custody and citizenship are discussed, which are described below.
Lineage: Most jurists consider the paternal lineage of the child to be the owner of sperm and its jurisprudential study is given in jurisprudential documents. Jabbari (2010) also confirms this in his article (19). Mahdavi Kani (2015) in confirming this issue, stated that the legislators required to take measures to ensure that the child is not deprived of inheritance rights (due to the law stating that the donor remains anonymous) (20). However, according to the provisions of the Convention on the Rights of the Child, the best interests of the child must always be taken into account when making decisions about the child. It is in the best interests of the child to join those who want to give birth to him and consider him their child, and in view of the above, motherhood is closer to who is the owner of uterus (21).
In Saffar's study (2004), it is stated that in the regulation of Article 3 of the law, the lineage of the child should be explicitly attached to the applicant couples so that the legal status in terms of inheritance and other effects and results of lineage becomes exactly determined (22). In confirmation of this issue in the study of Mahdavi Kani (2010), jurists based on Islamic principles, in the field of lineage, it is desirable to attach the child to the recipients of the fetus with all its effects, including inheritance, compulsory province, will and citizenship (23). Inheritance: Those who consider the paternal lineage of the child to be the owner of sperm, believe that the child inherits from the same father.
Marriage: In fact, marriage with a relative or causal incest is not permitted. Therefore, permitting or not permitting marriage is based on establishing a relative and causal relationship.
Alimony: Those who attribute the child to the owner of the sperm, in the first way should consider alimony obligatory on him. Mahdavi Kani (2010) in this regard states that finally, according to the legal nature of alimony, it is better to consider the obligation to require alimony as two-sided (23).
Custody: What is said about alimony for a child born through donation is also true about custody.
Citizenship: Those who attribute the child to the owner of the sperm, if he is Iranian, must also consider the child Iranian (24).
There are ambiguities in the law of Iranian embryo donation, the most important of which are: not referring to permanent or temporary marriage of couples, not mentioning forced guardianship, one of the effects of which is permission in marriage, the issue of privacy is not clearly explained in this law. The number of donation is not limited in this law, the number of appeals for non-approval of the couple's eligibility is not stated, is there a right to terminate the contract of embryo donation or not? The share of inheritance of the born child is also not clearly stated (25). Other articles such as Mahdavi Kani (2010) and Riyazat (2012) also point to these ambiguities in the law (23,26). Other defects of the law on embryo donation in Iran include the lack of reference to how to provide their living cost and if one of the recipient spouses die or the occurrence of divorce (27).
Larijani (2007) also stated that due to the exclusion of people with AIDS and hepatitis from the embryo donation process, these patients should not be deprived of this right and this issue should be reconsidered by policy makers (28).
Jurisprudential documents
Islam has a positive and balanced view regarding assisted reproductive technologies (ART) (29). As the legal effects of embryo donation stated in the section on legal documents, these effects should also be examined from a jurisprudential and religious point of view. Regarding surrogacy, Jahani Shoorab and Latifnejad (2016) stated that in Iranian law, different aspects of surrogacy are not clear. There is rejection of surrogacy by Sunni scholars and disagreement between Shia scholars. According to Nosrati (2019) regarding the gametes donation, the law of Iran has been silent and jurists also disagree on the legitimacy of this issue (30). Therefore, one of the most important jurisprudential issues regarding embryo donation in the first step is whether the obligatory ruling of these methods is permissible or haram and the rulings on the status of these methods, what is the lineage, confidentiality and inheritance?
The jurists have different opinions according to the type of inference from verses and narrations. Ayatollah Tabrizi, Behjat, Lankarani: The transfer of the fetus to the womb of a woman other than the husband's spouse is not considered permissible. Ayatollah Sistani, Makarem Shirazi, and Khamenei: If it does not require another mahram, such as haram looking and touching, there is no religious obstacle. In the case of the religious permission of the above practice, avoiding the forbidden precepts has been emphasized by all jurists (31). Bajestani (2018) also in this regard stated that each of the hypotheses of artificial insemination has a specific rules and status (3). Khalafi (2006) also about the principle of embryo donation stated that in the process of embryo donation, because there is no direct contact between the germ cells and the applicant's uterus and the transfer of the embryo to the uterus is not equal to the transfer of sperm and egg, there is no legal prohibition (32). Maghsoudi (2017) in emphasizing on Tabatabai's study (2020) on the differences of opinion of jurists on the principle of embryo donation emphasizes that among the jurists, in addition to Ayatollah Tabrizi and Lankarani, Ayatollah Nouri Hamedani also does not consider this practice legitimate (33).
Lineage of the child: Regarding the paternal lineage of the child, the prevailing theory among Shiah and Sunni jurists is that the child is attributed to the owner of the sperm (embryo donor couples), so the embryo recipient couples have no lineage to the child, because there is no evolutionary or biological relationship between them. The Guardian Council opinion is that the born child is attributed to the donor couples (2). Poor Ismaili (2017) also confirms this issue according to the verses and narrations, and many contemporary jurists, including Ayatollah Behjat, Khamenei and Makarem, Lankarani also quotes the aforementioned verses and narrations: the sperm owner is considered the legal father of the child (34,35). Tabatabai (2020) in his article also expressed the difference of Ayatollah Tabrizi's opinion that: the resulted child is the child of the woman who the child was grown in her uterus, and is the child of the man who was born from his sperm. Khalafi (2006) also argues and confirms this issue in his article (24).
Islamic jurists and scholars also have different opinions about the maternal lineage of the born child. Most jurists and jurists believe that the woman who is the egg owner is the mother of the child, and some believe that the recipient woman who raise the child in her womb and give birth is the mother of the child, and some have considered both to be the mother of the child. But according to the beliefs and reasons of Alavi Qazvini (2018) and Safiri (2009), the woman who is the uterus owner is the mother of the child (21). Samadi (2012) also believes that a child born from a donated fetus has two mothers. This theory is not far from Islamic law because in addition to the original mother, the breastfeeding mother is also considered a mother. There is no longer discussion by accepting these cases which are approved by many jurists. The owners of sperm and eggs have no place in terms of relative kinship and the child joins the recipient couple (35).
Inheritance: Another legal effect of the embryo donation is inheritance, which in the study of Tabatabai (2020), the opinion of the jurists is that Ayatollah Tabrizi: The resulted child is the child of the woman who grew up the child in her womb and is the child of man whose sperm was used and he inherits from them. Ayatollah Behjat, Lankarani, Makarem Shirazi and Khamenei: The child inherits from his parents (sperm owners) (31). Khalafi (2006) also stated that the jurists who attribute the fetus to the owners of sperm and eggs believe that the child inherits from them. The jurists who consider the owner of the womb to be the mother, the rules of inheritance prevail between them (Ayatollah Khoei) and those who have chosen the theory of two mothers believe that the child inherits from both mothers (24).
Marriage and intimacy: The jurists who attribute the fetus to the owners of sperm and eggs, usually apply all the rules related to lineage. Ayatollah Sistani and Montazeri: In the case of two mothers involved, caution should be considered in arranging of maternal and child sentences.
Ayatollah Makarem: Ommol-Baladiyeh is a breastfeeding mother and her fat and bones originated from her, so marriage between her offspring and this woman is forbidden (24). The jurists have same opinion regarding secrecy.
Custody: According to the best interests of the child, the jurists have given custody to the owners of the womb, and those who consider both mothers to be the mother of the child should determine which of the two mothers has priority in custody. While the law gives custody to the recipients (24). In general, considering the importance of family based on certain jurisprudential rules and moral foundations, the jurists establish meetings and clarify and publish the dark points of jurisprudence, in order to jurisprudential rules and opinions regain their position in this field and also families get rid of the confusion caused by conflicting opinions (26).
Ethical documents
The most important ethical issues related to embryo donation include informed consent, screening of donors and recipients, confidentiality, financial issues of donation and other issues related to embryo donation. The four principles of medical ethics include respect to individual independence, profitability, non-harm, and the principle of justice, which are widely used today as a guide in practical decisions regarding medical ethics.
According to the principle of respect to individual independence, recipients and donors should be aware of what they intend to do, as well as its conditions, so before starting treatment, counseling about the treatment process and its risks should be provided to couples. Also, according to this ethical principle, the confidentiality of information about embryo donors and recipients is essential.
Considering the two principles of profitability and non-harm, the embryo recipients and donors should be screened. Some people with necessary characteristics and competencies are recognized, and some other are excluded from the treatment process. In terms of disclosing or not disclosing the secret of donation to the child and others, it seems that according to the two principles of justice and respect to individual independence, the right of the resulting child to be aware of his biological origin is a moral necessity. Also, considering the principle of non-harm from a jurisprudential point of view and preventing incestuous marriage in the future and the possibility of the resulting child needing to use transplanted organs in special cases, it seems necessary that the identities of gametes and embryos donors be registered and how to access this information according to instructions and rules be determined.
According to the principle of justice, it is better to plan the process in such a way that it is possible to compensate the financial costs of donors, and according to the principle of non-harm, the intended amount should be chosen in such a way that minimize the possibility of excessive incitement to donate and abuse it (36). According to Yahyaee (2018), the rights of those born from donation based on the moral principles of respect for the individual independence, justice is rarely observed, and the ethical principles of profitability and non-harm are sometimes observed (37).
One of the most important issues in the field of ethics is the confidentiality and disclosure of the main identity of the child resulting from the donation. In this regard, the study of Aramesh (2007) stated that it is morally correct and necessary to record and maintain information about the identities of gamete and embryo donors and recipients in the relevant centers and to disclose them for children at appropriate time, and these people can inherit from their biological parents (38). Contrary to what has been said, Larijani (2007) stated that the confidentiality of the gamete donor should be maintained, and therefore records must be protected by the strictest confidentiality standards, and to facilitate this process, pre-treatment counseling courses should be provided for recipients to inform them of various aspects (28). It is necessary to formulate national ethical guidelines in this field according to the different aspects of the issue and the different consequences of these new technologies (28).
Conselling of recipient and donor couples
Studies regarding the counseling of embryo donation are limited and is mainly focused on the importance of ongoing information and counseling in resolving potential problems arising from this treatment. There is no doubt about the necessity of counseling in both medical and psychiatric wards and that one of the duties of infertility counseling centers is to counsel both recipient and donor couples (39). Infertility counseling organizations recommend that all infertile patients should have access to counseling services before, during and after infertility treatment, and these services should be provided to all those who use third-party reproduction to maintain family cohesion (40). Hadizadeh Talasaz et al. (2015) stated that the majority of couples seeking infertility treatment tended to hide the process and results of treatment from others, and the most important reason was concern about the society and the negative opinions of others. The society's non-preparation to accept various methods of assisted reproduction has led to the couple being deprived of emotional support and enduring a lot of psychological pressures. Therefore, evaluating the cultural and social beliefs of couples in specialized counseling is very important (41).
Also in the study by Latifnejad Roudsari et al. (2016), it is stated that collaborative counseling reduces perceived stress in infertility (42). In counseling infertile couples, considering the psychological characteristics of couples, religious and cultural beliefs is very important. One of the common ways to deal with the psychological stress caused by infertility and the resulting treatments is to resort to religious beliefs (43). Also in the study of Nilforoushan and colleagues who showed that counseling based on the approach of interactive cognitive subsystems, improves the attitude of infertile couples towards infertility (44). The legal issues such as inheritance and possible moral aspects such as endangering the life of the carrier mother will increase the need for continuous and comprehensive counseling (30). In the study of Baniaqeel, it is stated that comprehensive counseling on infertility and third-party fertility has significantly improved the attitude of research units (40).
Discussion
Nowadays, scientific advances and the discovery of various treatment methods for treating couples' infertility have made it possible for families to have children, thus preventing the breakdown of families. On the other hand, observing the religious, moral and legal aspects of the methods, especially the method of embryo donation, requires that more attention be paid to these dimensions of the methods (31). In fact, embryo donation is one of the methods that must be designed and implemented in accordance with the cultural and social conditions of any society (23). The various aspects surrounding this issue have created gaps in these dimensions for infertile couples involved in treatment. The method of embryo donation in Iran is legally and jurisprudentially accepted. But there are still defects and ambiguities in this regard.
However, in countries such as France, legal issues are clearly stated, for example, in French law, the child is considered to be joined to the recipient couples, and all the effects of legitimate lineage, including inheritance, are given to him (9). The law of embryo donation in Iran has defects that will undoubtedly face problems in the future with implementation and theorizing, and it is better to reform it. Among these defects are the following: not mentioning the permanent or temporary marriage of the couple, not mentioning the compulsory guardianship tht one of the effects of which is permission in marriage, the issue of privacy, the number of donations, which is not limited, the number of appeals, non-confirmation of the spouses' eligibility, the right to terminate the embryo donation contract, is there or not? The right of the recipient couples to the child, the share of inheritance of the born child is also not clearly stated (25). Review of those with AIDS and Hepatitis and not to deprive them of embryo donation (28), not to mention the effect of divorce or terminating marriage in the transfer of the fetus, the method of transfer after the husband's death (7), the preference for the use of frozen embryos (45) are some of the things that can be added as a supplement to the law of embryo donation.
In reviewing the published articles, another important issue in the legal aspect is that the rules of the contract of sell cannot be attributed to the embryo donation and the payment for it is invalid because human beings cannot be bought and sold (25-27). But in fact, the stages of donation should be separated so that in the first stage, people can sell their eggs and sperm, and in the laboratory stage, there is no case to sell, but in the stage that enters to the uterus, because the embryo has legal personality and human dignity, cannot find a financial position (3, 25, 28). Another issue in the law of embryo donation in Iran is the confidentiality of the main identity of the child that the anonymity of the donor spouses causes less legal and emotional conflicts in the future for the donor and recipient couples (5, 15). But this does not seem to be morally correct because, according to the two principles of justice and respect for individual independence, the resulting child's right to be aware of his or her biological lineage is a moral principle (40, 24).
Another important and debatable issue is determination of the lineage of the child, which most jurists attribute it to the owners of sperm and eggs (16, 17). However, regarding the best interests of the child, which are emphasized in the holy Shari'a of Islam and the international conventions that emphasize the rights of the child, the lineage must be clearly stated in the law and belong to the recipient couples (18-21). Regarding the Shari'ah permission for embryo donation, by reviewing the articles, most of the most frequent and contemporary jurists have allowed embryo donation and have emphasized only the avoidance of forbidden preliminaries (36-38), but nevertheless, it should be emphasized to couples that refer to their imitation reference. According to Islamic law, most jurists consider the lineage of the child to be the owner of sperm (2, 39, 36, 22). This issue should be clearly stated in the law and should be communicated to the recipient couples.
One of the positive points of this study was providing the necessary legal, jurisprudential and ethical information on embryo donation together for counseling services providers for couples as well as infertile couples applying to receive donated embryos and also for donor couples. One of the limitations of this study was the existence of few studies in Iran on how to conduct counseling, especially in the method of embryo donation, which requires counseling to both recipient and donor couples. It is recommended that in embryo donation counseling, the most important related issues such as the dimensions mentioned in the study be considered.
Conclusion
Embryo donation is one of the infertility treatments that require comprehensive and specialized counseling services. Counselors who provide counseling services in these areas should be fully aware of most areas related to treatment to be able to provide the necessary guidance to couples, including the legal, jurisprudential and ethical aspects of the method which helps a lot in the decision of infertile and donor couples. It is recommended to provide these tips in the infertility consultation process.
Acknowledgements
The faculty librarians for their cooperation in searching for articles is hereby thanked and appreciated.
Conflicts of interest
Authors declared no conflicts of interest.