1@Multifetal pregnancy as a consequence of reproductive treatment
| | Multifetal pregnancies as a consequence of reproductive treatment are divided into two categories. One results from ovulation induction (use of ovulation inducers) and the other from in-vitro fertilization. In ovulation induction, a hormone that stimulates follicle development and ovulation (e.g. gonadotrophin) is administered to treat infertility caused by ovulatory disorder. As a result, many follicles develop fully, ovulate simultaneously and more than one sperms fertilizes the eggs, thus causing multifetal pregnancy. In the case of in-vitro fertilization, several fertilized eggs are transplanted into the womb. If more than one of such eggs nidate, this leads to multifetal pregnancy. |
| | According to a study on mental and physical disorders conducted by the Health and Welfare Ministry in 1996, "Study on Infertility Treatment" (Takumi Yanaihara), 46.7% of triplet pregnancies were caused by in-vitro fertilization,43.2% were caused by ovulation induction and 8.5% were natural pregnancies. In the case of quadruplet pregnancies, 52.9% were caused by in-vitro fertilization, 41.2% by ovulation induction and 3.9% were natural pregnancies. Among quintuplet pregnancies, 66.7% were caused by ovulation induction, 33.3% by in-vitro fertilization and there were no natural pregnancies. |
| | Multiple pregnancies have been on the increase in recent years. The study on mental and physical disorders conducted by the Health and Welfare Ministry in 1996, "Epidemiology of Multiple Pregnancy" (Yoko Imaizumi) shows that the birth rates of twins, triplets and quadruplets in 1995 were 1.3 times, 4.7 times and 26.3 times higher than in 1968, respectively. These increases seem to be attributable to the increased use of medical technology for reproduction. |
1@Risks associated with multiple pregnancy
| | According to a report by the Perinatal Committee of the Japan Society of Obstetrics and Gynecology in 1995, the weight of newborns decreases as the number of fetuses per pregnancy increases. Twins weigh 2,153}703g, triplets weigh 1,673}485g, quadruplets weigh 1,203}359g, and quintuplets weigh 993} 249g (average}standard deviation). In addition, the miscarriage rate increases as the number of fetuses increases: twins 1.7%, triplets 2.4%, quadruplets 15.0% and quintuplets 15.0%. The miscarriage rate is particularly high in the case of quadruplets and quintuplets. |
| | The fetal death rate in the perinatal period after the 22nd week of pregnancy (against 1000 births) increases as the number of fetuses increases: twins 75.0, triplets 75.3, quadruplets 102.9 and quintuplets 125.0. The incidence of sequelae of one-year-old or older babies is 4.7% for twins, 3.6% for triplets, 10.2% for quadruplets and 30.8% for quintuplets. This rate is particularly high in the case of quadruplets and quintuplets. Cerebral palsy, retardation and retinopathy of prematurity are major sequelae. |
| | The chance of maternal complications increases as the number of fetuses increases: twins 78.1%, triplets 84.1%, quadruplets 95.0% and quintuplets 100.0%. |
| | As shown above, high-order multifetal pregnancies with four or more fetuses cause a high likelihood of maternal complications and have adverse effects on newborns. |
1@Fetal reduction
| | Fetal reduction is an operation that causes fetuses to die in the womb. It is used for the purpose of relieving mothers from the risks associated with pregnancy and childbirth of multifetal pregnancy and to ease the burden of raising many children. The generally practiced method is to inject potassium chloride into the heart of the fetus. |
| | According to a questionnaire survey in the above-mentioned "Study of Infertility Treatment", fetal reduction was performed in 87 cases among the 195 medical institutions that returned the questionnaire. The majority of the 15 institutions that performed fetal reduction are clinics. |
| | Fetal reduction is an operation that causes fetuses to die in the womb, whereas the Maternal Protection Law stipulates that "artificial abortion is an operation to artificially remove a fetus in the development stage from the mother's body that cannot sustain life outside the mother's body along with its appendage". Therefore, it has been pointed out that fetal reduction is not an operation that is stipulated under the Maternal Protection Law. |
| | As to the method of selecting the fetuses that will be subject to reduction, in some cases in foreign countries, fetuses were selected based on the presence of any defect or on the gender of the fetuses. These cases touched off an argument on the ethical aspects of this issue. |
1@How multifetal pregnancy reduction has been dealt with to date
| | Looking back on how multifetal pregnancy reduction has been dealt with by the organizations concerned, the Japan Association of Obstetricians and Gynecologist announced its official view on fetal reduction in 1993, saying that fetal reduction does not fall under the category of artificial abortion as defined in the Eugenic Protection Law (the current Maternal Protection Law), and might be subject to punishment as a criminal abortion. |
| | The Japan Society of Obstetrics and Gynecology announced its view on "multifetal pregnancy" in February 1996. It stated that, in regard to multifetal pregnancy as a consequence of medical technology for reproduction, we should go back to the root of the problem and resolve it by preventing multifetal pregnancies from occurring. The society demands that the number of embryos implanted in in-vitro fertilization and embryo transplantation programs be limited to three in principle, and that the use of gonadotrophin preparations per ovulatory cycle for the purpose of ovulation reduction be reduced as far as possible. |
1@Basic idea on fetal reduction in multifetal pregnancy caused by medical technology for reproduction
| | Although a fetus is not a human being, it develops into a human being. Needless to say, its life must be respected. One of the purposes of the provision concerning criminal abortions of the Criminal Code and the Maternal Protection Law is the protection of the life of the fetus. |
| | To some extent it is possible to prevent medical technology for reproduction from causing multifetal pregnancy. In the case of in-vitro fertilization, the number of fetuses does not usually exceed the number of fertilized eggs transplanted into the womb. In the case of the transplantation of three or more embryos, it has been proven that the pregnancy rate does not increase in proportion to the number of fertilized eggs implanted. Some say that a high pregnancy rate can be achieved by implanting two fertilized eggs. |
| | As for ovulation induction, new methods have been developed that can achieve high rates of single ovulation by improving the method of administering gonadotrophin preparations or by reducing the use of gonatropin preparations per ovulatory cycle. |
| | Considering these factors, the problem of multifetal pregnancy as a consequence of medical technology for reproduction should be resolved by preventing its occurrence. Adjusting the number of fetuses by fetal reduction without making any efforts to prevent multifetal pregnancy does not respect the life of the fetus. Such practice should not be permitted. |
| | However, even if measures are been taken to prevent multifetal pregnancy as described below, it is impossible to completely prevent multifetal pregnancy using technology currently available. Taking into consideration the fact that high-order multifetal pregnancies with four or more fetuses cause a high rate of maternal complications and have adverse effects on newborns, fetal reduction may be permitted in some cases. |
1@Policies on multifetal pregnancy reduction
(1) Measures to be taken in in-vitro fertilization
| | The incidence of multifetal pregnancy caused by in-vitro fertilization can be substantially reduced by reducing the number of ferilized eggs to be transplanted into the womb. Based on the facts shown above; 1) that high-order multifetal pregnancies with four or more fetuses carry a high rate of maternal complications and have adverse effects on newborns, 2) that in the case of the transplantation of three or more embryos, the pregnancy rate does not increase in proportion to the number of eggs implanted, and 3) that a high pregnancy rate can be achieved by implanting two fertilized eggs, it is appropriate to limit the number of fertilized eggs to be transplanted into the womb in in-vitro fertilization to two in principle, or three depending on the respective conditions of the fertilized eggs and the womb. |
| | Prior to in-vitro fertilization, it is necessary to inform the patient of the risk of multifetal pregnancy caused by the transplantation of more than one fertilized egg. It is also necessary to identify the number of fetuses that the patient is willing to carry by providing sufficient information and counseling. If the patient does not want twins and strongly desires to have only one child, one fertilized egg should be implanted. If the patient is happy to give birth to triplets and the patient's health is considered good enough to give birth to triplets, three fertilized eggs should be implanted. These adjustments are necessary in the light of reproductive health/rights. |
(1) Measures to be taken in ovulation induction
| | Ovulation induction is not only associated with the risk of multifetal pregnancy but also with ovarial hyperstimulation syndrome. Therefore, this method should only be carried out by a highly-skilled doctor. |
| | Prior to ovulation induction, it is necessary to inform the patient of the risk of multifetal pregnancy caused by ovulation induction and to provide sufficient information and counseling to the patient. If the patient is unhappy with the rise of multifetal pregnancy, ovulation inducers should not be used in light of reproductive health/rights. |
| | Since there are no established measures to prevent multifetal pregnancy caused by ovulation induction, studies in this field should be promoted by the government and related academic societies. At the same time, use of the single ovulation induction method should be encouraged. |
(1) Fetal reduction
| | Fetal reduction does not fall into the category of artificial abortion as defined by the Maternal Protection Law. This committee consider this to be a correct view on the grounds that; 1) fetal reduction causes fetuses to die inside the womb, 2) although the dead fetuses are expelled at the time of delivery, it is different from artificial removal, and 3) the Maternal Protection Law does not contemplate such surgery to be fetal reduction. |
| | In principle, fetal reduction should not be practiced as stated above. Therefore, we consider there to be no need to modify the provisions concerning artificial abortion in the Maternal Protection Law. However, some are of the opinion that the issue of the interpretation or modification of such provisions should be discussed. |
| | However, in cases where multifetal pregnancy (involving four or more fetuses, or three in exceptional cases) occurs despite the fact that preventive measures have been taken, fetal reduction may be permitted if it is needed to protect the lives of the mother and child. |
| | Whether to perform fetal reduction and the details of the surgical procedure should be determined after careful consideration of each case in the light of the need to protect the lives of the mother and child. |
| | Fetuses subject to reduction should not be selected on the basis of genetic factors or gender. |
| | Fetal reduction carries the risk of unintentional infection of potassium chloride into the mother's body. Therefore, the operation should only be performed by a highly skilled doctor. |
| | Furthermore, it is necessary to inform the patient of the possibility of losing all the fetuses as result of fetal reduction and to obtain their consent to the procedure. |
1@Essential activities of government and related academic societies
| | In order to ensure that measures to prevent medical technology for reproduction from causing multifetal pregnancy are properly implemented and that the conditions for fetal reduction are completely satisfied, the government and related academic societies should establish regulations governing multifetal pregnancy reduction. |
| | In addition, the government and related academic societies should establish a system to ensure that these regulations are observed. Under such a system, for example, medical institutions that have the ability and facilities necessary to perform multifetal pregnancy reduction should be designated and registered. Fetal reduction should only be performed by these registered medical institutions, and such medical institutions should be required to report the cause of the multifetal pregnancy and the reason for the fetal reduction operation. |
| Name | Title |
| Michiko Ishii | Professor at Faculty of Law, Tokyo Metropolitan University |
| Toku Ishii | Professor at Faculty of Nursing Science, Iwate Prefectural University |
| Hisatake Kato | Professor at Faculty of Law, Kyoto University |
| Katsuyuki Takahashi | Honorary Director of Sendai National Hospital |
| Kenichi Tatsumi | Vice-Director of Umegaoka Women's Hospital |
| Atsushi Tanaka | Director of St. Mother Hospital |
| *Kinko Nakatani | Professor Emeritus at Keio University |
| Eiji Maruyama | Professor at Faculty of Law, Kobe University |
| Takumi Yanaihara | Professor Emeritus at Showa University |
| Yasunori Yoshimura | Professor at Faculty of Medicine, Keio University |
*Committee chair