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Where am I now? Lawlink > Law Reform Commission > Publications > 2. The Practice of IVF
Discussion Paper 15 (1987) - Artificial Conception: In Vitro Fertilization
2. The Practice of IVF
I. IVF IN “THE MOST COMMON SITUATION"
A. Introduction
2.1 This part of the Chapter describes the IVF procedures which are undertaken in “the most common situation”, that is, where a husband and wife supply their own reproductive tissues for the production of conceptuses to be transferred to the uterus of the wife in the expectation that she will become pregnant.1 Specific techniques will not be discussed in detail as they are subject to constant change and indeed methods may differ slightly from clinic to clinic. Even so, the IVF process can be broken down into distinct stages which reflect the collective experience of most IVF patients.
B. Selection of Patients and Counselling
2.2 In general, couples requesting IVF are referred to a clinic from an outside source; they do not simply contact the clinic themselves. They may be referred by a general practitioner, a medical specialist or a hospital clinic. Some “proof” of infertility is usually a pre-requisite for acceptance into a waiting list. Infertility may be established from prior medical history or by a specified period of unsuccessful attempts to become pregnant. There may be some upper age limit on applicants to a program, although not all clinics impose an arbitrary age restraint.2
2.3 Factors which a clinic might take into account when deciding whether to accept a couple into a program include some or all of the following:
- stability of couple or household;
- heterosexuality or homosexuality of applicant; type of household;
- income of household;
- other children in household;
- physical disability of one or both applicants; and
- mental disability of one or both applicants.
In New South Wales, some clinics have indicated that they will accept heterosexual couples living in de facto marriages into their programs, though this is not necessarily the case in other States whether through intended legislative prohibition (as in Victoria)3 or the clinic’s own perception of community disapproval. Current information suggests that the waiting list for IVF treatment in New South Wales may be anything from six months to 18 months long.4 Counselling is usually offered at an early stage.
C. Beginning a Treatment Cycle
2.4 When a woman’ s name has reached the top of a clinic’s IVF waiting list, she is advised that she will be accepted into the treatment program the following month. The woman telephones the clinic on the first day of tier menstrual cycle and monitoring of her cycle begins immediately. Although early IVF successes were achieved in the natural ovulatory cycle, in New South Wales all clinics perform stimulation of a woman’s ovaries to create a controlled cycle. This involves the administration of a stimulatory drug in the early weeks of a woman’s natural cycle which causes the ovaries to release more than one ovum.
2.5 The timing of the ova pick-up procedure is critical. if too late, the ova will already have been released, and if too early the ova will be insufficiently mature and the chance of normal fertilization greatly reduced. However, the ova need not be fully mature at recovery and may be allowed to “ripen” in culture fluid for several hours before fertilization is attempted.5
D. Ova Recovery
2.6 The “traditional” method of ova collection was by way of laparoscopy, a surgical operation commonly used for exploratory purposes. The operation, usually performed under a general anaesthetic, involves the introduction of a laparoscope (an instrument for viewing internal organs) into the abdominal cavity through a small incision in the navel. During laparoscopic pick-up the surgeon views the ovaries through the laparoscope and manipulates them until any “ripe” follicles are spotted. The surgeon then inserts an aspiration needle into a follicle and draws off fluid within which the egg is suspended.
2.7 The success of a laparoscopic pick-up depends upon the accessibility of a woman’s ovaries. A woman suffering severe pelvic adhesions which render her ovaries inaccessible to laparoscopy would in the past have had to rely on the use of donated ova if she wished to become pregnant. However, it is now common to recover ova by more advanced techniques using “ultrasound”. The advantages are said to be:
(i) that recovery can be performed under local anaesthesia, which reduces the overall risk to the woman undergoing treatment;
(ii) that a needle can be guided to the ovary using ultrasound pictures so that direct viewing of the ovary is not necessary and women whose ovaries are inaccessible for laparoscopy can be treated;6
(iii) that recovery is quicker and stress greatly reduced; and
(iv) that the procedure, being capable of use on an outpatient basis, may be far less costly to the IVF patient.
A number of Australian clinics now use ultrasound for all ova recoveries.7 Ultrasonic ovum recovery was originally attempted using an aspiration needle passed through the bladder and into the ovary. New techniques involve passage of the needle through the lateral wall of the vagina and into the ovary. This is perceived to involve less risk, although it can cause some discomfort to the patient.8
E. Assessment of Semen and IVF
2.8 The retrieved ovum is transferred to a dish containing a liquid culture medium and allowed to “ripen” there for a number of hours, depending on its maturity. Meanwhile, the woman’s partner provides a specimen of semen. The specimen is examined, and motility and sperm concentration is estimated. The semen is “centrifuged”, a process used to “harvest” the most highly motile (or vigorous) sperm and remove dead sperm and other debris in the semen.
2.9 When the ovum has reached a sufficient level of maturity, the prepared semen is added to the dish containing the ovum. This is the “insemination” process. The composition of the culture medium in which the gametes are placed is of prime importance in ensuring the growth of viable embryos. The culture medium will usually contain more than 15 chemical ingredients and the proportions of those ingredients are critical. Apart from composition of media, other culture conditions must be consistent with survival of the gametes. Temperature, oxygen levels, humidity and pH balance are all factors of importance.
2.10 The dish containing sperm and ovum is placed in an incubator for approximately 12 hours. At the end of that time, the dish is examined to determine whether fertilization is taking place. Fertilization begins with contact between a single sperm and an ovum. The complete process will take from 22 to 30 hours and is described in more detail in Chapter 8.9
2.11 The fertilized ovum (also called “zygote,” “conceptus,” “IVF embryo” and “preimplantation embryo”, among other names) will begin to undergo a series of cell divisions so that between 50 and 78 hours after insemination, it has grown from one cell to eight cells.10 The quality or health of the preimplantation embryo is judged by the rate at which its cell divisions occur, as well as its appearance:
In a normal embryo, the cells are regular in outline and approximately equal in size. Irregularity of cells or distortion of shape indicates abnormality. Experience shows that an embryo with abnormal appearance or very slow growth no longer has the potential to form a human life.11
F. Embryo Transfer (ET)
2.12 Once the conceptus has reached a sufficient stage of development, it may be transferred to the uterus. The stage of development judged “sufficient” by the IVF practitioner may be anything from the one-cell to the 16-cell stage.12 The ET procedure itself is a reasonably simple one, although in order to reduce risks of infection, it is usually performed in an operating theatre. The conceptus is placed in a fine tube or catheter which is passed through the woman’s vagina and cervix, into the uterus. The conceptus is then released near the top of the uterus. After the transfer, the woman is advised to rest for a few hours, after which time she may leave the clinic.
2.13 Commonly, more than one conceptus will have developed from the ova retrieved in the earlier egg pick-up procedure. The probability of a pregnancy resulting from one ET is greatly increased if more than one conceptus is transferred, although this practice also increases the likelihood of multiple pregnancies.13 In general, two or three conceptuses are transferred in a single procedure of ET, if they are available.
G. Post ET Management
2.14 Following a procedure of ET, the hormone levels of the recipient woman are monitored to determine whether or not she has conceived. if a fertilized ovum has implanted in the woman’s uterus, levels of certain “pregnancy” hormones in her bloodstream will steadily rise. Measurement of these levels may be used as a criterion for diagnosis of pregnancy, called ‘chemical pregnancy” or “biochemical pregnancy”. Pregnancy is more normally confirmed around seven weeks from the beginning of the patient’s last menstrual period by means of ultrasonic scan of the uterus, which will also provide information regarding the number of fetuses in the uterus and the viability of any fetus present.
2.15 Spontaneous abortion after diagnosis of a clinical pregnancy (that is, after one menstrual period has been missed and the presence of a fetus confirmed on ultrasound examination) occurs in 12 to 30 per cent of pregnancies following IVF and ET.14 The spontaneous abortion rate in natural conception following diagnosis of a clinical pregnancy is considerably lower : in the order of 10 to 15 per cent.15 Studies indicate that the higher incidence of spontaneous abortion following IVF and ET may be related to the use of super-ovulatory drugs rather than the IVF procedure itself.16
2.16 As the IVF pregnancy continues, monitoring of fetal condition continues with monthly blood tests, regular ultrasound scans to assess fetal growth and daily fetal movement counts which are done by the patient herself. Although, in the absence of complications, “there is no reason why the spontaneous onset of labour and normal vaginal delivery should not occur”,17 the Caesarean section rate amongst IVF patients is more than three times that of other patients. A possible explanation for this substantial difference is that the IVF patient is usually older than the typical obstetric patient, and this fact, if combined with a history of pelvic surgery, may make obstetric complication more likely.18
H. IVF Success Rates
2.17 It is difficult to estimate the success rate of IVF generally because clinics do not interpret their results by uniform standards. Success is often measured by reference to pregnancies achieved. However, a clinic which calculates its success rate by reference to pregnancies following ET and eliminates from its calculations failures occurring before ET will appear to have a greater rate of “success” than a clinic which calculates its rate by reference to pregnancies following laparoscopy.19 A success rate related to pregnancies following ET really indicates success of the transfer procedure (and implantation) and not of the IVF procedure as a whole. One commentator has proposed pregnancies “per induced cycle” as perhaps the fairest indicator of success,20 since such a formulation would recognize the risk of failure involved in each step of the entire IVF procedure. The profile of a particular patient may indicate the likelihood of success in her case. For example, young women with unexplained infertility of short duration are more likely to become pregnant than older women whose infertility has not been cured after years of treatment.
2.18 The definition of “pregnancy” for the purposes of the estimation of success is a contentious matter. A survey of 1510 IVF pregnancies occurring in Australia and New Zealand during the period 1979 to 1985 showed that only 869 or 57.5 per cent of those pregnancies resulted in a live birth.21 So-called “chemical” pregnancies which as mentioned above are diagnosed from slight elevations in the level of a certain hormone and ectopic pregnancies, where pregnancy occurs outside the uterus, are classified as successful pregnancies on this approach.
2.19 Another proposal is to ignore the various means of estimating the success of IVF by reference to achieving “pregnancy”, and to gauge “success” by reference only to live births, having regard to:
(i) the total number of women receiving a complete course of treatment in a program over a given period (for example, one year); and
(ii) the proportion of those women who bear a child.
2.20 The figures generally cited as IVF pregnancy success rates range between 8 and 30 per cent depending upon the basis of diagnosis.22 Of these pregnancies, 25 to 30 per cent will not proceed to live birth given current conditions of Australian IVF practice. IVF experts believe that continuous increases in these success rates are “certain”.23
2.21 A criticism often levelled against IVF is that the success rate of the procedure is low. Implicit in this criticism is the assumption that the pregnancy success rate following an IVF procedure should be compared with the pregnancy success rate of natural conception. In fact, such a comparison is not valid; women being treated on IVF programs cannot, in general, conceive naturally. For those women, the pregnancy success rate of natural conception is close to zero. A more meaningful comparison would involve juxtaposing pregnancy success rates following an IVF procedure or course of IVF procedures, with pregnancy success rates following other forms of treatment for infertility. A real analysis of IVF success rates should involve not only consideration of pregnancy rates but also of the costs of IVF, both financial and otherwise. What would be necessary, in other words, would be an evaluation of the social cost of IVF.
I. Costs
2.22 The average cost to the IVF patient of a single treatment cycle is between $3000 and $4000 when treatment is given on an “in-patient” basis by a hospital.24 Currently, Medicare refunds 85 per cent of all scheduled medical fees, and most patients have private health insurance which will refund the 15 per cent “gap”. Amongst the costs not included as scheduled medical fees, and therefore borne by the patient or perhaps to some extent her private health insurer, are:
- the cost of drugs used to stimulate the ovaries;
- the laboratory costs of handling the collected eggs, effecting fertilization and culturing of fertilized eggs until transfer; and
- the costs of gynaecologist and scientist attending for embryo transfer.
The net cost to the patient may be expected to be between $700 and $800. One hospital clinic in Sydney performs IVF with ultrasound-guided ovum pickup on an outpatient basis, so that the total cost of a single treatment cycle is approximately $650. After Medicare rebates, the patient’s out-of-pocket expenses may be as low as $100 to $150 per treatment cycle.25
2.23 The patient will also incur indirect costs in the nature of loss of wages and travelling expenses. The Commission is conscious that these costs may put IVF treatment beyond the financial capacity of some people. However, we are aware of federal government initiatives to abolish the present system of Medicare rebates for IVF procedures and replace it with a system of health program grants. Under this arrangement, the federal government would allocate funds to “approved” IVF centres to cover medical, pathology and drug costs on the understanding that IVF services could be provided to patients at a greatly reduced cost.
II. CRYOPRESERVATION OF REPRODUCTIVE TISSUES
A. Fertilized Ova
1. Why Preservation is Practised
2.24 A single IVF treatment cycle need not involve preservation of genetic material. In the typical case, an ovum is taken from a woman, fertilized with the (fresh) sperm of her partner and replaced in the woman’s uterus in the same treatment cycle. However, in one IVF treatment cycle, a number of factors may operate to render undesirable or impossible the transfer to the patient of all the ova retrieved or fertilized in that cycle. Medical opinion is that a fertilized ovum, if allowed to develop in vitro past the eight- to sixteen-cell stage is unlikely to implant after ET.26 If ET must be delayed, freezing or “cryopreservation” will arrest growth and preserve them until such time as transfer is desirable.
2.25 The practice of administering fertility drugs to IVF patients increases the likely need for preservation. The reason is that fertility drugs stimulate ovulation, causing large numbers of ova to be released in a single cycle and hence the Likelihood of larger numbers being recovered in a single laparoscopy or retrieval. It is well documented that the practice of replacing more than two conceptuses by ET during the treatment cycle increases the pregnancy rate in IVF patients.27 However, current medical opinion is that such replacement increases the likelihood of multiple births and that for medical and social reasons multiple births should be carefully controlled. Accordingly, no more than two or three fertilized ova are normally transferred on any one occasion. As not all ova will be successfully fertilized when exposed to semen, and not all fertilized ova will develop into normal embryos, clinicians follow the practice of attempting to inseminate all recovered ova. The clinician will normally choose ET for those that are adjudged to be most suitable. Supernumerary or “excess” conceptuses are then likely to be preserved for the couple.28
2.26 Fertility drugs may also upset a woman’s hormonal balance and alter the uterine environment, making it more difficult for a fertilized ovum to implant.29 Hence, it may be preferable in some cases to delay ET and preserve the conceptus until a subsequent spontaneous ovulatory cycle is experienced by the recipient woman.
2.27 Embryo preservation technology may increase the efficiency of IVF treatment by:
(i) reducing costs and risks of repeated laparoscopies - ova recovered at a single laparoscopy can be fertilized and replaced in the uterus on different occasions; and
(ii) giving a greater prospect of a successful pregnancy, because the fertilized ova can be implanted in such numbers and at such times as will be considered most favourable for pregnancy.
2. How it is Done
2.28 Once it is apparent that a particular ovum has been fertilized, it is cultured in vitro and allowed to develop, usually to the four- to eight-cell stage. A “cryoprotectant”, which protects the cells during freezing, is added before the cooling process begins. The fertilized ova, packaged in special glass vials are placed in a biological freezer and cooled to -6șC.30 Once ice begins to form, they are cooled further and transferred to liquid nitrogen for storage. When the conceptus is needed, it is thawed and cultured for a further time to allow recovery of cell function and assessment of any damage. If 50 per cent or more of the original cells appear normal, the conceptus may be transferred to the recipient woman. Research has shown that a fertilized ovum which has sustained damage to some of its cells may still develop normally to term,31 and there is no indication of an increased rate of abnormalities in children born following embryo preservation, although as yet the test sample is very small.32 The first “frozen embryo” baby was born in March 1984 in Melbourne.33 Since then, a number of other babies have been born following successful application of the technique including, in February 1985, the world’s first frozen embryo twins.34
2.29 Theoretically, a preserved fertilized ovum can be stored indefinitely. There is no evidence to suggest that it will deteriorate with time. It is during the actual freezing and thawing processes that it may suffer damage. Studies indicate that “a majority” of such conceptuses will successfully survive the freeze-thaw process. 35
B. Semen
2.30 IVF may be performed using frozen rather than fresh semen. This is advantageous if the concentration of sperm in the ejaculate of the woman’s partner tends to vary from normal to subnormal levels, or if the partner is anxious about producing a semen sample at the time of ovum recovery.
Alternatively, if donor sperm is necessary, it will usually be frozen. One disadvantage of using frozen sperm is that sperm motility and fertilizing ability may be reduced.36 However, this aspect is not particularly important in the context of IVF, since relatively few motile sperm are needed to achieve fertilization in the laboratory, and studies indicate that in such context there is “no significant difference in the fertilization rates between frozen-thawed and fresh spermatozoa”.37 The advantages of using frozen donor semen, rather than fresh semen, are:
(1) the ready availability of donor semen for IVF
(2) the possibility of screening for sexually transmittable disease and bacterial contamination
(3) the convenience of drawing semen from the large donor pool... [and]
(4) the possibility of using frozen-stored semen from the same donor for a subsequent pregnancy following IVF - ET.38
The method of freezing and storing semen is similar to that described for fertilized ova. Briefly, semen is diluted with a cryoprotectant, cooled slowly to a critical temperature then cooled rapidly and transferred to liquid nitrogen for storage.39 Like the embryo it appears that sperm can be stored indefinitely; any damage is caused during the freezing and thawing processes rather than during storage.
C. Ova
2.31 While it has been possible to freeze and thaw human sperm and embryos for some time, successful freezing and thawing of human ova proved difficult. The difficulty arises because the ovum is only a single cell, and unlike the many-celled conceptus which in its early stages has the capacity to recover completely after losing some cells, any damage to the ovum or its surrounding membrane will result in its total destruction. In late 1985, the Flinders Medical Centre in Adelaide announced the world’s first pregnancy from frozen and thawed human ova.40 The pregnancy culminated in the birth of healthy twins in July 1986.41
2.32 The successful ovum freezing procedure involved culturing the eggs to maturity, then “trimming” them to enable the cell to absorb the cryoprotectants which help to prevent damage during the freezing process.42 An advantage of the procedure is that a number of ova can be recovered in a single laparoscopy and those not needed immediately can be stored for later use. Also, there are fewer ethical objections to freezing ova than to freezing fertilized ova. However, serious reservations about the safety of ovum freezing in the light of present technology have been exposed by scientific experts, including Dr Alan Trounson.43
III. DONATION OF REPRODUCTIVE TISSUES
A. The Fertilized Ovum
2.33 It is appropriate to speak of freezing and donation in sequence because the use of cryopreservation techniques makes donation of fertilized ova a more viable proposition. In order to use “fresh” fertilized ova for donation, it is necessary to synchronise the menstrual cycles of donor and recipient women, so that the recipient’s uterus will be ready to accept the fertilized ova at the time they become available. The donor may be a woman undergoing IVF herself ,44 and it will not be known until after her ovum recovery how many of her (recovered and fertilized) ova will be fit to be replaced in the uterus, nor whether the “donor” has any ova to spare. Unless the “spare” fertilized ova can be frozen, there will be no time to synchronize the cycle of donor and the recipient. It will be a matter of chance as to which recipient woman is at the critical point in her cycle to sustain a pregnancy.45 Cryopreservation of a fertilized ovum eliminates the need to synchronize the cycles of donor and recipient. The donated conceptus can be stored until such time as the recipient is ready to receive it. On the other hand, when cryopreservation technology is available IVF patients also have the option of freezing their “excess” fertilized ova for their own use at a later date and may choose to do so, rather than to donate them.
B. Semen
2.34 IVF might be attempted using donor sperm when the partner of the recipient woman is infertile, for example, due to “azoospermia”, the total absence of sperm in the semen. Given the difficulty of obtaining fresh donor semen at short notice, the semen used is likely to have been frozen.46 As has already been said (para 2.23), in the context of IVF, fertilization rates for frozen-thawed and fresh spermatozoa are substantially the same. Successful pregnancies have been achieved following use of frozen-thawed donor semen in IVF programs.47
2.35 Our inquiries of IVF clinics in New South Wales and Victoria indicate that donors whose semen is used in IVF programs are recruited and screened in the same way as donors whose semen is used in an AID program. The sperm donor’s expenses are reimbursed, but he is not paid a fee for his “donation”.48
C. Ova
2.36 A woman may be a potential candidate for IVF treatment using donated ova if her infertility stems from:
- congenital absence of ovaries;
- loss of ovaries due to disease or surgical intervention;
- premature menopause;
- severe pelvic adhesions preventing access to ovaries; or
- inherited genetic disease likely to result in fetal abnormalities.49
In the recent past, use of donated ova required synchronization of ovulation of donor and recipient, since ova could not be successfully stored. Once ovum freezing techniques are established, this synchronization will no longer be necessary.
Footnotes
1. Victorian Report (1982), para 5.5.
2. Information obtained from answers obtained from a confidential survey conducted by the New South Wales Law Reform Commission entitled Questionnaire for IVF Clinics (issued in 198S).
3. See Infertility (Medical Procedures) Act 1984 (Vic) ss10, 11, 12 and 13.
4. Information supplied by New South Wales IVF clinics (11 June 1987): Royal North Shore Hospital, Sister Beadle; Westmead Hospital, Ms Linda Robinson; St George Hospital, Ms Gail Porter; Royal Prince Alfred Hospital, Sister Durst; Lingard Hospital, Sister Oliver.
5. Wood and A Trounson (eds) Clinical In Vitro Fertilization (1984) at 102, 103.
6. C Wood and A Westmore Test-Tube Conception (1984) at 72.
7. Information supplied by Dr A Trounson in June 1987.
8. A survey of the response of patients to the transvaginal pickup procedure, conducted by nursing staff at one clinic, disclosed that 50 per cent of patients were satisfied with the procedure, 30 per cent experienced some discomfiture and 20 per cent would have preferred a general anaesthetic. See R P S Jansen “Acceptance by Patients of Outpatient Transvaginal Follicle Aspiration with Local Anaesthesia” (1986) 4(6) Clinical Reproduction and Fertility 410.
9. See paras 8.4 to 8.9; see also note 5 at 108, 109.
10. Note 6 at 74; note S at 109.
11. Note 6 at 74. It has recently been discovered that the viable embryo produces a substance called “platelet activating f actor” (PAF) shortly after fertilization and throughout the preimplantation stage of development. Production of this factor showed a positive correlation with the “pregnancy potential” of the embryo. At some future time, it might be possible to judge the health of the preimplantation embryo by measuring its output of this factor: M Collier et al “The purification and quantification of human embryo - derived platelet activating factor (PAF) using a sensitive bioassay” (1986) 4(6) Clinical Reproduction and Fertility 435; C O’Neil “The activity of embryo-derived platelet activating factor is necessary for the establishment of pregnancy in mice” (1986) 4(6) Clinical Reproduction and Fertility 423; L M Adamson et al “Studies on platelet activating factors in mouse and human pregnancy”(1986) 4(6) Clinical Reproduction and Fertility 433.
12. Note 6 at 74 and 75; A Trounson and C Wood (eds) In Vitro Fertilization and Embryo Transfer (1984) at 199.
13. A Trounson and C Wood (eds), note 12, at 199.
14. Id at 206. See also National Perinatal Statistics Unit Report (1987) at 26, table 23.
15. A Trounson and Co Wood (eds), note 12 at 207; also S Fishel and E M Symonds (eds) In Vitro Fertilisation Past Present Future (1986) at 141.
16. S Fishel and E M Symonds (eds), note 15, at 142.
17. A Trounson and C Wood (eds), note 12, at 210.
18. Id at 20.
19. So-called “failures” of IVF procedures occurring before transfer really only refer to failures to fertilize. There is no basis for comparison of such figures with those for natural conception for obvious reasons.
20. Comment of Dr Sander Shapiro, University of Wisconsin IVF Clinic, Madison reported by G Corea “Priorities”, paper delivered at New South Wales Law Reform Commission (6 May 1986) at 17.
21. National Perinatal Statistics Unit Report (1987) at 22, table 11.
22. See eg D Brahams “The Legal and Social Problems of In Vitro Fertilization: Why Parliament Must Legislate - 1” (1983) 133 New Law Journal 859 at 859; Family Law Council Report at para 5.5. 2. Dr A Trounson has advised orally that some United States clinics are currently claiming success rates of 30% (June 1987).
23. A Trounson and C Wood (eds), note 12, at 227. Information supplied by Dr A Trounson at Artificial Conception Division Meeting of New South Wales Law Reform Commission (11 November 1986).
24. Information supplied by Dr Burton, President of Infertility Federation of Australasia, 10 June 1987.
25. Ibid.
26. Note 5 at 119-120.
27. A Trounson and L Mohr “Human pregnancy following cryopreservation, thawing and transfer of an eight-cell embryo” (1983) 305 Nature 707; note 5 at 120.
28. Note 5 at 63.
29. A Trounson and C Wood (eds), note 12 at 123.
30. Id at 125.
31. See note 27 at 707.
32. Ibid.
33. The Australian, 11 April 1984 at 1; The Sun, 11 April 1984
34. Sydney Morning Herald, 26 February 1985 at 6.
35. See note 27 at 709.
36. Ciba Foundation Law and Ethics of AID and Embryo Transfer (1973) at 5.
37. M Mahadevan et al “Successful use of human semen cryobanking for In Vitro fertilization” (1983) 40(3) Fertility and Sterility 340 at 340.
38. Id at 342.
39. Id at 341.
40. The Age, 18 December 1985 at 5; The Australian, 18 December 1985 at 1.
41. The Australian, 5 July 1986 at 1.
42. The Age, 18 December 1985 at 5.
43. Information supplied by Dr Alan Trounson, June 1987.
44. Note 2.
45. Note 12 at 123.
46. Note 37 at 340.
47. Id at 342 ; see also National Perinatal Statistics Unit Report (1987) at 24, tables 17, 18.
48. Note 2.
49. Note 5 at 22.
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