A survey of infertility, surgical sterility and associated reproductive disability in Perth, Western Australia Sandra Webb Health Services Statistics and Epidemiology Branch, Health Department of Western Australia, Perth

D’Arcy Holman Departmat of Public Health and Department of Management, The University of Western Australia, Perih Abstrack Infertility, surgical sterility and associated reproductive disability were studied in a stratified cluster sample of 1 51 1 couples with women aged 16 to 44 years resident in metropolitan Perth in 1988. Sixteen couples were omitted from analysis because of missing data. The proportion of couples affected by current infertility was 3.5 per cent (53 of 1 495), and 67.9 per cent of these (36 of 53) had a reproductive disability, meaning that they were unable to achieve their desired level of reproductive function. Those affected by surgical sterility accounted for 37.1 per cent (555 of 1 495), and of these couples 2.0 per cent (1 1 of 555) had a reproductive disability. Empirically, the prevalence of both infertility and reproductive disability peaked at ages 30 to 34 years in the female partner. Of the factors studied, infertility was associated with surgery for a ruptured appendix, a history of pelvic inflammatory disease and number of sexual partners. In 10 of the 47 couples with reproductive disability, contraceptive sterilisationhad been a cause of later regret. Most other cases were due to infertility. Almost one half of couples with reproductive disability had sought treatment. The affected couples had at least one child from the current union in 23 of the 47 cases of reproductive disability. The results support the need for development of a strategy to prevent infertility and other causes of reproductive disability. (Aust J Public Heulth 1992; 16: 376-81)

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ittle information exists on the occurrence of infertility and other reproductive problems in the Australian population. Information is available on childlessness’.’ and demographic trends in family size,”5 but the primary objectives of these studies are too far removed to shed much light on the subject of infertility. With the rapid development of in vitro fertilisation (IVF) and other reproductive technologies, there is an increasing need for public health professionals to become involved in planning for the appropriate and affordable use of this technology. There is an urgent need for ongoing assessment of new treatments for infertility as well as the potential demand for treatment services. Moreover, there is a need to inform health policy makers of a broader view of reproductive failure that takes into account its antecedent causes and social context. The aims of this study were to measure the extent of reproductive problems due to infertility and sterility in an Australian urban population and to explore their characteristics and associations with other factors. Our report also explores some of the methodological issues that we encountered.

Method The following definitions were observed: Infertility applies to a couple after one year of unsuccessful efforts to become pregnant, marked by a conCorrespondence to Dr Sandra Webb, Health Statistics and Epidemiology Branch, Health Department of Western Australia, 189 Royal Street, East Perth WA 6004

376

tinuous relationship with intercourse unprotected by contraception or surgical sterility.6 Surgical sterility applies to a person who has undergone a tubal ligation, hysterectomy, bilateral oophorectomy, vasectomy, bilateral orchidectomy or other surgical procedure that has stopped the reproductive function. Infertility, therefore, is a medical diagnosis which in its strictly defined form excludes couples in which at least one member has been surgically sterilised for contraceptiveor other reasons, because they have no chance of achieving a pregnancy through intercourse. It is important to clarify the definitionsbeing used, as some couples affected by sterilisation do attend IVF clinics and are treated as if they were cases of tubal infert ti lit^'.^ There is also a tendency to refer to the long-term infertile as ‘sterile’, and the expression ‘subfertility’ has been applied to the short-term infertile.n The study of infertility in populations is further complicated by problems in defining the correct denominator at risk; that is, whether couples have had regular unprotected intercourse. The standard medical definition implies that couples test their fertility in a way that may not match actual behaviour.n Moreover, infertility need not be a permanent state. It may be resolved by a pregnancy or a couple may cease to engage in unprotected intercourse. For these reasons, current infertility must be distinguished from ever having been ix~fertile.~.~ A useful alternative to the medical definition of infertility may be obtained from the perspective of

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the couple who may or may not perceive that a fertility or sterility problem exists, which restricts their ability to attain a desired level of reproductive function. Such an approach is especially germane to the planning of infertility services as these couples are the ones likely to seek assistance from the health system. To describe this concept we have coined the term reproductive disability which we define as follows: Reproductive disability applies to a couple who because of biomedical or psychosocial factors are unable to achieve their desired level of reproductive function. Reproductive disability may be caused by: pre-coital factors; for example, genetic disorders, sexual dysfunction, variations in sexual orientation; post-coital factors; for example, infertility or surgical sterility; or post-implantation factors; for example, recurrent miscarriage, pregnancy as a severe health risk to the mother. This report is restricted to the occurrence of reproductive disability among couples affected by infertility or surgical sterility, and therefore provides information on only the second of the above categories. We suggest that future investigators consider all three categories of reproductive disability, because couples affected by precoital and postimplantation problems may also turn to reproductive technology or other means to minimise their handicap. Sample The sample was drawn from women residing in the Perth metropolitan area, aged 16 to 44 years, whose conjugal status was mamed or defacto. The sample was drawn using a cluster, multistage method to select dwellings representative of the metropolitan area. A total of 150 census collectors’ districts was selected with a probability proportional to size. Starting from a random point in each district, interviewers were instructed to select dwellings in succession until interviews were obtained from ten women who met the survey criteria. After each interview a skipinterval of two dwellings was applied. Women only were interviewed, and they were asked for information about themselves and the relationship, and some information about the men. In designing the sampling method, we made a decision not to call back on dwellings, but rather to use sampling conditions to minimise any bias caused through omission of women who were not at home when the interviewer called. It was considered plausible that infertility could have a positive association with absence from the home during usual employment hours. For this reason interviewingwas carried out at evenings and on weekends, and, based on an initial question on employment status, the sample was stratified by completing equal numbers of interviews with women employed and not employed outside the home. This was done to represent the distribution observed in the 1986 census, in which 54 per cent of mamed women resident in the Perth metropolitan area were found to be employed out-

side the home. It is our view that any additional validity that could have been obtained through call-backs, over and above out-of-hours interviewing and sample stratification, did not justify the extra cost that would have been incurred. The sample was broadly representative of the heterogeneity of the Australian community. Among the women interviewed, 1.7 per cent described themselves as Aboriginal, 3.1 per cent were born in Southeast Asia or India, 2.3 per cent were partnered with unemployed men and 19.1 per cent described their partners as working in a professional occupation. Interuiews

Interviewing was performed in September to December 1988 by 12 experienced female interviewers who were trained in advance to deal with the complexities and sensitivities of the collected information. The response fraction, expressed as women who agreed to participate divided by women contacted, was 90.3 per cent. Among those interviewed, only eight women refused to answer one of the most sensitive questions, which concerned the number of their sexual partners. Average interview time was approximately 15 minutes. A total of 1511 interviews was performed. Despite testing the survey instrument on 20 preliminary interviews, one problem with the questionnaire was not uncovered until data analysis commenced. Forty-seven women reported not using contraception despite having no aspiration to become pregnant. We obtained further information from 31 of these women and found that in 28 instances they were users of the withdrawal, rhythm, barrier or surgical methods which they did not associate with the term ‘contraception’, believing it to apply only to oral contraceptives or intrauterine devices (IUDs). Their responses were amended accordingly. The 16 women who could not be contacted again were excluded from the analysis. Data analysis Measures of prevalence of infertility, surgical sterility and associated reproductive disability were constructed using all couples with an eligible female as the denominator and those reporting each of these conditions at the time of survey as the numerator. Confidence intervals for prevalence estimates were calculated by the method of Wilson.Io Prevalence ratios and cumulative incidence ratios were used to indicate the strength of association between infertility and possible causal factors. The confidence intervals for prevalence ratios and cumulative incidence ratios were obtained using a natural log transformation.Il Stratified analysis was performed using precision-based weighting; the statistical significance of a trend in effect measures was assessed using the Mantel extension test.”

Results The prevalence of current infertility in couples with a female partner of reproductive age was 3.5 per cent (53 of 1 495). The prevalence of surgical sterility in

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Table 1 : Prevalence of current infertility, sur ical sterility and associated reproductive disabfity according to age of the female partner

Woman’s Number of age (years) couplesa

I6 to 19 20 to 24 25 to 29 30 to 34 35 to 39 40 to 44 All women

do not distinguish between voluntary and involuntary childlessness.

Current infertilitya

Surgical steriliv

Associated reproductive disability

25 1 46 315 382 342 285

-

-

-

2.1 3.8 4.2 3.5 3.5

2.1 12.4 31.7 53.5 72.2

1.4 3.5 4.1 3.7 1.7

1 495

3.5

37.1

3.1

95% CI Mean age

SE

2.6-4.4

34.7-39.5

2.2-4.4

33.3 5.8

37.2 4.7

32.9 5.1

Infertility There were 53 cases of current infertility, and a total of 285 women (19.1 per cent of 1 495) reported infertility at some time in their lives (lifetime infertility). The 53 cases of current infertility included 12 women with primary infertility, who therefore had never been pregnant. In women aged 40 to 44 years, and therefore at the end of their reproductive lives, the lifetime cumulative incidence of ever having been infertile was 22.8 per cent. A majority (67.9 per cent) of the 53 currently infertile couples had an associated reproductive disability. Twenty-eight women reported a cause of infertility. Causes were tubal pathology (8),male problems (7), female congenital anomalies (5), disorders of ovulation (5). early menopause (2), or endometriosis (1). We compared current infertility in the couple and lifetime infertility experience in the female partner with the woman’s number of sexual partners, history of pelvic inflammatory disease, ever-use of an IUD and history of appendicectomy with or without rupture of the appendix. Because these potential determinants varied with age, and lifetime infertility experience was also age-related, it was considered necessary to stratify the analysis by age, using six groups from 16 to 19 to 40 to 44 years. The results are shown in Table 2. It was found that the risk of infertility increased with the number of the woman’s sexual partners, and the risk was greater in women with a history of pelvic inflammatory disease or surgery for a ruptured

Note: la)For current infertility and surgical sterility there were 16 cases where information was missing.

couples was 37.1 per cent (555 of 1 495). and the prevalence of reproductive disability associated with either infertility or surgical sterility was 3.1 per cent (47 of 1 495)(see Table 1). Empirically, women aged 30 to 34 years had the highest proportions of infertility and reproductive disability, whereas the prevalence of surgical sterility increased progressivelywith age, reaching 72.2 per cent by 40 to 44 years in the female partner. The present marriage or defacto relationship was childless in 22.6 per cent of couples. For women aged 40 to 44 years the prevalence of lifetime childlessness was 6.9 per cent, and the current relationship was childless in 12.8 per cent. These data

Table 2: Relationship of current infertility ond infertility in the past in the female partner to different factors after adjustment for age Any history of infertility ( n = 285)

Current infertility ( n = 53)

Factor

Number in catego@

Prevalence ratio

95%

confidence interval

P

Number in Cumulative categorp incidence ratio

95%

confidence interval

P

Number of sexual partners One

2 to 5 >6

1 .o

623 632 239

1.5 1.7

1 .o

0.19

623 632 23 1

0.34

1299 186

1 .o

0.8 to 3.3

0.5 to 1.6

0.62

1070 423

0.8 to 2.7 0.7 to 4.1

1.2 1.3

1.0to 1.5 1.0 to 1.8

0.04

1.3 to 2.1

0.0001 .

0.8 to 1.3

0.98

History of pelvic inflammatory disease

No

1 306

1 .o

Yes

186

1.6

1.7

Ever-use of intrauterine device

No Yes

1070 423

1 .o

0.9

1 .o

1 .o

History of appendicectomy

No Yes Yes, ruptured

1155 260

1 .o

0.6to 2.5

0.61

1155 260

1 .o

1.3

1.3

0.9 to 1.6

0.11

57

2.3

0.8 to 6.6

0.16

57

2.1

1.5 to 3.6

0.0001

Note: la) In some instances the sum of respondents is less than 1 495 because information is missing.

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appendix. The power to detect a statistically significant association was greater for lifetime than current infertility, because the experience of infertility at some time of life was reported over five times more often. P-values for the relationships of lifetime infertility to multiple sexual partners, pelvic inflammatory disease and appendicitis with rupture were less than 0.05. There was no evidence of a relationship of current or lifetime infertility with use of an IUD.

Surgical sterility In 555 couples at least one partner was surgically sterile, and in 23 instances surgical sterility was present in both partners (see Table 3). Very few couples (2.0 per cent of 555) affected by surgical sterility had an associated reproductive disability. Couples with multiple causes of surgical sterility were classified into a hierarchy according to likely primary cause. For example, it was assumed that tubal ligation would have preceded hysterectomy. A similar assumption was made for cases of vasectomy and hysterectomy. Table 3 shows the distribution of primary causes of surgical sterility based on this approach. Tubal ligation and vasectomy (contraceptive sterilisation) accounted for 87.2 per cent of all primary causes. Hysterectomy in the absence of prior tubal ligation or vasectomy accounted for 12.8 per cent of primary causes. The prevalence of hysterectomy in all women surveyed was 7.2 per cent. Reproductive disability Table 4 shows characteristics of the 47 couples in whom reproductive disability was reported to be associated with infertility or surgical sterility. They comprised 36 infertile couples and 1 1 affected by surgical sterility. Of the latter group, contraceptive sterilisation had been a cause of later regret in 10 instances. Fifteen (32 per cent) of the women reporting reproductive disability were without children. Among couples with reproductive disability the current relationship was childless in about one half (24 of 47) of cases. In the remaining 48.9 per cent there was at least one child born of the current union, but the couple were unable to realise their desire for more children due to secondary infertility or surgical sterility. Table 3: Causes of surgical sterility in 555 couples Couples reporting cause n %

Cause Sterile partner Female only Male only Bath partners

329 203 23

59.3 36.6 4.1

Primary causeo Tubal ligationb Vasectomy Hysterectomy

263 22 1 71

47.4 39.8 12.8

Note: (a)

See text for explonotion of primory couse.

Ibl Includes one instonce of tubol ligationin the female, in which the mole was also surgicolly sterile due to vosectomy.

Table 4: Characteristics of reproductive disability in 47 infertile or surgically sterile couples Couples reporting characteristic n %

Characteristic Nature of impairment Infertility Surgical sterility

36 11

76.6 23.4

Issue from current union Childless At least one child

24 23

51.1 48.9

Medical treatment sought In-vitro fertilisation clinic Infertility specialist Gynaecologist General practitioner None

7 3 10 3 24

14.9 6.4 21.3 6.4 51.1

Nearly half of the 47 couples had sought medical treatment for their reproductive disability, and about half of those seeking treatment had been to an infertility specialist or IVF clinic. Among the total of 1 51 1 women surveyed, 182 had become pregnant within the last 12 months, and 14 (7.7 per cent) of these pregnancies were achieved following medical intervention, presumably for reproductive disability. The forms of assistance provided were IVF (l),tubal surgery (5), hormonal therapy (3), male treatment (2) and other measures such as cycle monitoring (3). Two-thirds (68.1 per cent) of the 182 pregnancies were planned pregnancies, and occurred after a median duration of trying to become pregnant of 3.5 months (range 1 to 96 months).

Discussion The prevalence of current infertility in Perth couples found in this survey (3.5 per cent) seems unusually low using international comparisons. In the US National Survey of Family Growth, 8.5 per cent of all married couples with women aged 15 to 44 years were infertile based on a definition similar to that used here." According to the World Health Organization, infertility affects five to eight per cent of couples in developed countries.I3 Other studies have provided information on lifetime infer ti lit^.^.^ A postal survey of 766 British women aged 46 to 50 years estimated the lifetime cumulative incidence of infertility to be 14 per cent.g This could be compared with the estimate of 22.8 per cent found in Perth women aged 40 to 44 years; however the definition of infertility used in the British study referred to 24 months rather than 12 months. In another report, combining the results from two different surveys, 24 per cent of British women aged 25 to 44 years indicated that an episode of infertility had occurred at some time in their reproductive lives8 This may be compared with 19.1 per cent in Perth women aged 16 to 44 years. None of these British studies was limited to defacto or married subjects as was the case in Perth. Explanations for differences in survey results between countries include artifact caused by variation in the definition of infertility, variation in

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sample selection criteria, and possibly by differences in perception, recall or access to medical care. Real differences may also occur because of variation in reproductive behaviour such as preferred age of childbearing, and in other determinants of infertility such as pelvic inflammatory disease and the surgical management of appendicitis. For example, pelvic inflammatory disease was reported by 12.5 per cent of women in this survey, compared with 17.2per cent of all currently married women aged 15 to 44 years in the United States in 1982.14 The prevalence of surgical sterility among Western Australian couples (37.1 per cent) was slightly lower than that reported from the United States in 1982, where 38.9 per cent of couples with women aged 15 to 44 years were affected.I4The high rate of hysterectomy in the United States compared with Australia could partly explain this very small difference. l5.I6 The study highlighted the potential for misinterpretation by survey subjects of what is meant by the term cunfruception. Similar observations have been made by other investigators who found that sterilisation and withdrawal were often not understood by women to be included.17.'8 Our results on contraception and unplanned pregnancy are described in detail in separate article in this issue (pages 382-6). However, accurate information on contraceptive use is crucial to the definition of infertility based on duration of exposure to unprotected sexual intercourse, and future survey instruments should be designed with care to prevent any misunderstanding by subjects. Of interest is the extensive questionnaire used in the US National Survey, which introduced the concept of contraception through a detailed series of questions.I4 Other authors have commented on the technical difficulties encountered in applying a definition of infertility that includes facets of human behaviour such as effective use of contraception and coital frequency in addition to the biological ability to conceive.8.19.20 Despite the highly personal nature of the survey questions needed to perform research on human reproductive issues, our experience, and that of other workers,J suggests that members of the public will participate in these studies provided that a professional and sensitive approach is adopted. In fact, our impression is that people are very interested in the topic of human reproduction, which may help explain the response fraction of 90.3 per cent, an unusually high fraction for a voluntary household survey. The results of this survey have important implications for the prevention of reproductive problems and the provision of health services to those who are affected. The concept of reproductive disability provides a practical indicator for the planning and evaluation of preventive and treatment services, firstly because it is specific to those cases in which functional impairments are a cause of ill-health, and secondly because it is potentially sensitive to all causes of reproductive problems and not just infertility. In the US National Survey of Family Growth, estimates of the level of need for services were obtained from a comparison of women's fertility aspirations with the 380

fertility status of the couple.21The definition of reproductive disability embodies a similar combination of desired level of reproductive function and the restrictions imposed by a functional impairment. There is a need to develop and to promote the concept of prevention of reproductive disability, especially because public perceptions of the problem are dominated by the high-profile and at times sensational treatment regimes. These results and other research point to a number of risk factors that should be addressed in a preventive strategy. For example, our observation that contraceptive sterilisation accounted for one fifth of all cases of reproductive disability has obvious implications for prevention, highlighting the importance that medical advice and counselling accompanying surgical sterilisation should cover psychosocial complications of the procedure, such as later reproductive disability, as well as the biomedical ones. A second risk factor is the age of the couple. Although this study was not designed to assess the biological relationship between age and infertility independent of contraceptiveand coital behaviour, it has been well documented by other researchers that female fertility declines with age, accelerating after the age of 30 years.":23 The proportion of women having their first baby at age 35 or over in Western Australia rose from 2.0 per cent in 1981 to 4.1 per Career and socioeconomic aspirations cent in 1988.24 on the part of both men and women are thought to underlie this trend. Community education programs about parenthood should provide more information on the relationship of infertility to age, as well as other biological and social issues related to matureage parenting. The objective of community education in these matters should be to empower women and men to make informed and balanced decisions about their career and life plans. History of surgery for ruptured appendix in the female partner is a risk factor. The proportion of all women surveyed who reported a ruptured appendix was 3.9 per cent. Combined with a relative risk of approximately 2.3, this suggests that the aetiologic fraction of current infertility caused by ruptured appendix may be in the order of 5 per cent. The results are consistent with those of Mueller et al in Seattle, who found that women with a history of r u p tured appendix had a threefold to fivefold increased risk of subsequent tubal infer ti lit^.'^ N o excess risk of tubal infertility was observed for simple appendicectomy, and Mueller et al argued that early diagnosis and treatment of suspected appendicitis in girls and women of reproductive age might reduce the occurrence of infertility in the community.25In fact, it is unlikely that much scope exists for reduction of this cause of infertility in Australia. The Australian rate of appendicectomy is already the highest among nine OECD countries, and is more than double the appendicectomy rates in the United States and Canada.I5J6 A fourth set of risk factors, also supported by evidence from elsewhere, is that of pelvic inflammatory disease and sexually transmitted diseases.2629It would be reasonable to assume that an effect of the

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number of sexual partners on infertility occurs because the risk of a woman acquiring a pelvic infection increases with the number of her sexual contacts.y9 Safe sex practices, including use of condoms and fidelity, should reduce the risk of reproductive disability. It is well known that some sexually transmitted diseases are major risk factors for tubal pregnancy, and other research has demonstrated a protective effect of condoms, particularly if a woman has more than one partner within a five-year period.Y0 Other causes of pelvic inflammatory disease include gynaecological procedures such as dilatation and curettage, abortion, insertion of an IUD and childbirth. We found no evidence to suggest an adverse effect on reproduction by the IUD, despite its association with pelvic inflammatoly disease. Other research has suggested that the IUD may have little appreciable effect on the risk of pelvic inflammatory disease among women with only one sex partner.Y'Based on our results the aetiologic fraction of current infertility caused by pelvic inflammatory disease is estimated to be seven per cent. Given the difficulty in ascertaining the occurrence of pelvic inflammatory disease in the past, we consider this figure is likely to underestimate the true fraction. Other preventable factors such as cigarette smoking and body mass index may be associated with infertility, but generally the evidence for these is weak and we could find no support for such associations in our results. A final factor concerns the expectations of the affected couples themselves and follows from the observation that about half the couples with reproductive disability had at least one child from the current union. This raises the questions of how to assess the severity of reproductive disability, and whether all cases should be eligible for the use of public resources to alleviate the condition. For example, we could ask the question, 'Should public funds be spent in providing an infertile or surgically sterile couple with their fourth, fifth or sixth child?' We do not presume to know the answer.

Acknowledgments The research was funded by a grant from the TVW Telethon Foundation. We thank Ms Jane Doyle for her assistance in development and coding of the questionnaire, and Dr Judy Straton and Dr Vivienne Waddell for their helpful comments in preparation of the manuscript. The Health Promotion Develop ment and Evaluation Program is an independent academic program supported by the Western Australian Health Promotion Foundation. References 1. Parliament of Australia. First report ofthe nufional population inquiry, Vol 1. Parliamentary paper 6. Canberra: Australian Government Publishing Service, 1975. 2. Economic and Social Commission for Asia and the Pacific. Population of Australia Country monograph series 9, N o 1. Geneva: United Nations, 1981. 3. McDonald P. The boom g m m t i o n as repmducers. Fertility inAurlmliainthcLatc 1970fandthc 19805. AustralianFamily Research Conference Proceedings. Melbourne: Institute of Family Studies, 1983.

4. Bracher MD. Are Australian families getting smaller? Australian Family Formation Project monograph 8. Canberra: Australian National University, 1981. 5. Young CM. The role of medical factors in the failure to achieve desired family size. J Biatoc Sci 1979; 11: 159-71. 6. Population Reports. lnfktility and sexually transmitted disease. A public health challenge. Series L, No 4. Maryland Population Information Program, 1983. 7. Webb S. In uitro fktilisation and related procedures in Western Australia 1983-87. A demographic, clinical and econmnic evaluation of participants and procedures. Occasional paper 26. Perth: Health Department of Western Australia, 1988. 8. Greenhall E, Vessey M. The prevalence of subfertility. A 9. 10. 11. 12. 13. 14:

15.

16. 17. 18. 19. 20. 21. 22. 23.

24.

25. 26. 27. 28. 29. 30.

31.

review of the current confusion and a report of two new studies. Fktil Stm'l 1990; 54: 978-83. Templeton A, Fraser C, Thompson B. The epidemiology of infertility in Aberdeen. Br Med J 1990; 301: 148-52. Wilson EB. Probable inference. The law of succession and statistical inference. J Am Staf Assoc 1927; 22: 209-1 2. Kleinbaum DG, Kupper LL, Morgenstein H. Epidemiologic research. Principles and quantitative methods. Belmont, California: Wadsworth. 1982. Hirsch MB, Mosher WD. Characteristics of infertile women in the United States and their use of infertility services. Fertil Skn'l 1987; 47: 618-24. World Health Organization. Infertility study cites major role of sexually transmitted diseases. Progress 1988; 5: 2-4. US Department of Health and Human Services. Fecundity, infqtility and reproduaive health in the US, 1982. Data from the National Survey of Family Growth, Series 23, No 14. Maryland DHHS, 1987. Holman CDJ. Brooks BH. Surgical procedures in Westem Ausin 1985 and tralia. An analysis of distdmtion of surgmy trends in surgical procedure rates 1972 to 1985. Penh: Health Department of Western Australia, 1987. Harvey R. Making it better. Strategicsfor improving the effectiuencss and quality of health smices in Australia. Background paper 8. Canbe&: National Health Strategy, 1991.Page H. Estimation of the prevalence and incidence of infertilGy in a population. A $lot study. Fcrtil Sfmil 1989; 51: 571-77. Lucas D. Australian family planning surveys. Some problems of comparability.J Biatoc Sci 1983; 15: 357-66. Grady WR, Hayward MD, Yagi J. Contraceptive failure in the United States. Estimates from the National Survey of Family Growth. Fam Plann Pmpcct 1986; 18: 200-9. Noller K. Close enough for highway work. Fcrtil S l m l 1990; 54: 976-7. Henshaw SK, Orr MT. The need and unmet need for infertility services in the US. Fam Plann Pmspcct 1987; 19: 180-6. Francis H. Age and human fecundity. IPPF Med Bull 1989; 23: 4. Novak D, Bergh PA, Williams M, Gamsi GJ, et al. Poor oocyte quality rather than implantation failure as a cause of age-related decline in female fertility. Lantct 1991; 337: 1375-7. Health Department of Western Australia. PniMtal statistics in W e s h Australia. Annual report of the W e s h Australian Midwives' Notification Systemfor 1988. Perth: Health Department of Western Australia. 1989. Mueller BA. Daling Jh, Moore DE. Weiss NS, et al. Appendectomy and the risk of tubal infertility. N Engl J Med 1986; 315: 1506-8. Westrom L. Incidence, prevalence and trends of acute PID and its consequences in industrialized countries. AmJ obstcr +ccol 1980; 138: 880-92. Weisberg E. Pelvic inflammatory disease. An overview. Healthright 1986; 5: 17-2 1. Anestad G, Lunde 0,Moen M, Dalaker K. Infertility and chlamydia infection. Fcrtil S k n l 1987; 48: 787-90. Sherman KJ, Daling JR, Weiss NS. Sexually transmitted diseases and tubal infertility. STD 1987; 14: 12-6. De-Kun L, DalingJR, Stergachis AS, Chu J, Weiss NS. Prior condom use and the risk of tubal pregnancy. A m ] Public Health 1990; 80: 964-6. Lee NC, Rubin GI. Borucki R. The intrauterine device and pelvic inflammatory disease revisited. New results from the Women's Health Study. Obstct CjMCcol 1988; 72: 1-6.

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A survey of infertility, surgical sterility and associated reproductive disability in Perth, Western Australia.

Infertility, surgical sterility and associated reproductive disability were studied in a stratified cluster sample of 1,511 couples with women aged 16...
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