COMMENTARIES
Millidot M. (1977)The influence of pregnancy on the sensitivity of the cornea Br J Ophthalmol61,646-649. Park S. B., Lindahl K. J., Temnycky G. O., DePaolis M. D. & Aquavella J. V. (1992) Corneal curvature modifications during pregnancy. Paper presented at CLAO annual meeting Las Vegas, Nevada, USA. Schirmer 0. (1903) Studien zur physiologie und pathologie der tra-
867
nenabsondcrung und tranenabfuhr, Albrecht von Graefes. Arch Ophthalmol56,1997-1291.
SunnessJ. S. (1988)The pregnant woman’s eye. Surv Ophrhalmol32, 21 9-238.
Weinreb R. N., Lu. A. & Beeson C. (1988) Maternal corneal thickness during pregnancy. Am J Ophthalmol105,258-260.
British Journal of Obstetrics and Gynaecology November 1992, Vol. 99, pp. 867-868
Antenatal HIV testing The increase in heterosexually acquired HIV infection has led to a rise in the number of seropositive pregnant women and children at risk of perinatal HIV infection (Johnson & Webster 1990; Norman et a/. 1990). Neonatal serosurveys claim that HIV prevalence in inner London rose from 1 in 2000 in 1988 to 1 in 500 in the first three months of 1991 (Adies et al. 1991). Offering HIV testing to antenatal women provides an unique opportunity of targeting the young sexually active population and making them aware of H€Vinfection while they are responsive to health education in their concern for the welfare of their unborn child. Anonymous unlinked antenatal HIV testing has been adopted in the USA and many European countries to provide some estimation of the seroprevalence in the heterosexual community. This method of testing is invaluable in providing epidemiological data but it is not useful to the individual woman, her unborn child or to those providing antenatal care as infected women cannot be identified. The most widely adopted method of antenatal testing in the western world is to concentrate on high risk women and test those who consent. However, there are great limitations as many women d o not know that they are at risk and a short interview at antenatal booking may fail to reveal high risk activities. High risk testing has been shown in several studies to miss a significant proportion of women who are seropositive. Obstetricians were aware of only 20% of maternal HIV infections identified by anonymous neonatal screening in three Thames regions between 1988 and 1991 (Adies et a/. 1991). In an inner city area of Baltimore, H I V detection was raised to 87% from 57% when offered to all antenatal women and not to just those who were identified as high risk (Barbacci 1991). The uptake of the test increased in both the nonhigh risk and high risk groups in this study by offering HIV testing as a routine, so removing the stigma attached to singling out a specific group. In Scotland, where HIV testing is more accepted than in England, 80% of infected pregnancies identified by anonymous neonatal screening were already known to be so to their obstetricians (Tappin et al. 1991). One of the arguments for implementing widespread ante-
natal H I V screening is that intrauterine infection does occur and accounts for the majority of H I V infection in children globally. The vertical transmission of HIV infection has been estimated to be approximately 13% by the recently reported European collaborative study group (European Collaborative Study 1991), while others have reported higher transmission rates (Italian Multicentre Study 1988; Hira et ul. 1989; Ryder et al. 1989). Differences in reporting infected pregnancies and less rigorous o r prolonged follow-up of children born to seropositive mothers may in part explain these higher transmission rates reported, and vertical transmission rates reported in studies from Africa may not be a true representation of events in the developed world. There is no method by which intrauterine infection can be determined, but there are certain factors which may influence maternal-fetal transmission. Women with advanced HIV infection are more likely to infect their offspring (Hira et al. 1989; Ryder eta/. 1989), and breastfeeding plays a small but significant role in perinatal transmission. The pregnancy outcome, for both mother and baby, is not significantly different between H I V positive and matched HIV negative women (Selwyn 1989; Minkoff et a/. 1990a; European Collaborative Study 1991), although some groups have reported that babies born to seropositive women were more likely to be premature and of lower birth weight (Hira et al. 1989; Braddick eta/. 1990). The obstetric management of the HIV seropositive woman is little different to that of her seronegative counterpart but knowledge of her status allows close monitoring of the HIV infection and drug treatment to be instituted promptly if complications occur. It appears that pregnancy does not affect the course of H I V infection in the asymptomatic individual, but women with advanced HIV infection are at risk of severe opportunistic infections whilst pregnant (Minkoff et al. 1990b). These women benefit from antiretroviral therapy. Recent reports of the use of Zidovudine in pregnancy are reassuring as there have been n o fetal malformations, excess prematurity, or fetal toxicity attributed to the use of this drug in HIV infected women (Sperling et al. 1992). Knowing the
868
COMMENTARIES
status of the pregnant woman also allows the infant born to a seropositive mother to be monitored postnatally and followed-up appropriately by the paediatrician for evidence of acquired infection. With these advantages why is HIV screening controversial? The test cannot predict the transmission of HIV to the fetus. It can take 12 weeks for seroconversion to occur during which time the woman may be most infectious. A negative test at the beginning of pregnancy may not be indicative of HIV status at delivery and efforts must be made to emphasize methods of reducing new exposure to HIV infection. There is concern as there is no cure for HIV. Offering HIV testing may cause severe emotional distrcss but there is evidence that once a woman is found to have a negative test there is no further anxiety related to HIV status during the rest of the pregnancy (Larsson el al. 1990). It has been suggested that a negative test result gives permission for adopting risky behaviour. Worries regarding discrimination by life insurance companies on disclosure of an HIV test can now be allayed since their clear statement not to penalise those tcsted as part of an antenatal screening programme, providing the test is negative. Finally, there is the objection that implementing voluntary HIV screening to all pregnant women would result in an enormous increase in workload in antenatal clinics, require specialist HIV counsellors, and would not be cost effective in terms of the prevalence of HIV infection. The antenatal booking clinic provides the ideal opportunity to raise the issue of HIV testing at the same time as the other prenatal screening programmes which are routinely being performed. Counselling is not a new o r difficult skill for midwives and doctors responsible for the care of pregnant women. This pre-test HIV counselling should normally be short and unambiguous with the possibility of specialist HIVi AIDS counsellors available for specific cases in much the same way as referrals to specialist genetic counsellors are necessary. The use of written leaflets about HIV infection and AIDS are helpful but do not substitute for pre-test counselling (Sherr & Hedge 1990). The time between the test and result should be short. This should not create extra visits as the HIV result can be given at the same time as the results of the other investigations performed at the booking visit. A positive test result can be given with support from the HIVi AIDS counselling services. Any screening programme must be cost effective, acceptable to the public and ultimately reduce the disease prevalence. The cost of implementing routine antenatal testing must be weighed up against the prevalence of HIV infection both in the UK as a whole and in individual areas. With the seroprevalence of HIV infection outside London remaining stable at 1 in 16 000, there is no case for instituting HIV testing as a routine investigation. We would suggest that in these areas of low seroprevalence it should be discussed with women during their antenatal booking visit and only offered t o those who have an identified risk factor. However, in areas with higher seroprevalence, such as inner London, we believe it should now be offered routinely. Pre-test counselling
should be brief, given by a midwife who has undergone training and testing undertaken of those giving consent. By making HIV testing more routine and thus less stigmatising, more people will be aware of possible HIV infection and accept the case for routine screening. K. H. McCarthy Research Registrar in Obstetrics and Gynaecology". M. A. Johnson Consulant Physician in HIV/AIDS" J. W. W. Studd Consultant Obstetrician & Gynaecologisfi
Royal Free Hospital, Pond Street, London NW3 2QG Kings College Hospital, Denmark Hill, London SE5
References Adies A. E. et al. (1991). Prevalence of maternal HIV-1 infection in Thames regions: results from anonymous unlinked neonatal testing. Lancet 337, 1563-1565. Barbacci M., Rcpke J. T. & Chaisson R . E. (1991) Routine prenatal screening for HIV infection. Lancer 337,709-71 1 . Braddiek M. R. (199jl) Impact of maternal HIV infection on obstetrical and early neonatal outcome. A I D S 4, 1001-1005. European Collaborative Study (1991) Children born to women with HIV-1 infection: natural history and risk of transmission. Lance1 337,253-260.
Hira S. K. et al. (1989) Perinatal transmission of HIV-1 in Zambia. B M J 299, 1250-1252. Italian Multicentre Study (1988) Epidemiology, clinical features and prognostic factors of paediatric HIV infection. Lancet ii, 1043-1 045. Johnson M. A. & Webster A. (1990) Human immunodeficiency virus infection in women. In Progress in Obstetrics & Gynuecology, Vol. 8. (Studd J. ed.) Churchill Livingstone, Edinburgh, pp. 175-1 90. Larsson G., Spangberg L., Lindgren S. & Bohlin A. B. (1990) Screening for HIV in pregnant women: a study of maternal opinion. AIDS Care 2 ( 3 ) 223-225. Minkoff H. L. (1990a) Pregnancy outcomes among mothers infected with human immunodeficiency virus and uninfected control subjects. Am J Obstet Gynecol163, 1598-1604. Minkoff H . L. (1990b) Serious infections during pregnancy among women with advanced human immunodeficiency virus infection. A m J Obstet Gynecol162,3040. Norman S.. Studd J. W. W. &Johnson M. A. (1990) HIV infection in women. BMJ 301, 1231-1232. Ryder R. W., Nsa W., Hassig S. E. etal. (1989) Perinatal transmission of the human immunodeficiency virus type 1 to infants of seropositive mothers in Zaire. N Eng J Med 320,1637-1642. Selwyn P. A. (1989) Prospective study of human immunodeficiency virus infection and pregnancy outcomes in intravenous drug users. JAMA 261,1289-1294. Sherr L. & Hedge B. (1990) The impact and usc of written leaflets as a counselling alternative in mass antenatal HIV screening. A I D S Cure 2, ( 3 ) 235-244. Sperling R . S. (1992) A survey of Zidovudine use in pregnant women with human immunodeficiency virus infection. N EngI J Med 326, 857-861. Tappin D. M. (1991) Prcvalenee of maternal HIV infection in Scotland based on unlinked anonymous testing of newborn babies. Lancet 337, 1565-1567.
Millidot M. (1977)The influence of pregnancy on the sensitivity of the cornea Br J Ophthalmol61,646-649. Park S. B., Lindahl K. J., Temnycky G. O., DePaolis M. D. & Aquavella J. V. (1992) Corneal curvature modifications during pregnancy. Paper presented at CLAO annual meeting Las Vegas, Nevada, USA. Schirmer 0. (1903) Studien zur physiologie und pathologie der tra-
867
nenabsondcrung und tranenabfuhr, Albrecht von Graefes. Arch Ophthalmol56,1997-1291.
SunnessJ. S. (1988)The pregnant woman’s eye. Surv Ophrhalmol32, 21 9-238.
Weinreb R. N., Lu. A. & Beeson C. (1988) Maternal corneal thickness during pregnancy. Am J Ophthalmol105,258-260.
British Journal of Obstetrics and Gynaecology November 1992, Vol. 99, pp. 867-868
Antenatal HIV testing The increase in heterosexually acquired HIV infection has led to a rise in the number of seropositive pregnant women and children at risk of perinatal HIV infection (Johnson & Webster 1990; Norman et a/. 1990). Neonatal serosurveys claim that HIV prevalence in inner London rose from 1 in 2000 in 1988 to 1 in 500 in the first three months of 1991 (Adies et al. 1991). Offering HIV testing to antenatal women provides an unique opportunity of targeting the young sexually active population and making them aware of H€Vinfection while they are responsive to health education in their concern for the welfare of their unborn child. Anonymous unlinked antenatal HIV testing has been adopted in the USA and many European countries to provide some estimation of the seroprevalence in the heterosexual community. This method of testing is invaluable in providing epidemiological data but it is not useful to the individual woman, her unborn child or to those providing antenatal care as infected women cannot be identified. The most widely adopted method of antenatal testing in the western world is to concentrate on high risk women and test those who consent. However, there are great limitations as many women d o not know that they are at risk and a short interview at antenatal booking may fail to reveal high risk activities. High risk testing has been shown in several studies to miss a significant proportion of women who are seropositive. Obstetricians were aware of only 20% of maternal HIV infections identified by anonymous neonatal screening in three Thames regions between 1988 and 1991 (Adies et a/. 1991). In an inner city area of Baltimore, H I V detection was raised to 87% from 57% when offered to all antenatal women and not to just those who were identified as high risk (Barbacci 1991). The uptake of the test increased in both the nonhigh risk and high risk groups in this study by offering HIV testing as a routine, so removing the stigma attached to singling out a specific group. In Scotland, where HIV testing is more accepted than in England, 80% of infected pregnancies identified by anonymous neonatal screening were already known to be so to their obstetricians (Tappin et al. 1991). One of the arguments for implementing widespread ante-
natal H I V screening is that intrauterine infection does occur and accounts for the majority of H I V infection in children globally. The vertical transmission of HIV infection has been estimated to be approximately 13% by the recently reported European collaborative study group (European Collaborative Study 1991), while others have reported higher transmission rates (Italian Multicentre Study 1988; Hira et ul. 1989; Ryder et al. 1989). Differences in reporting infected pregnancies and less rigorous o r prolonged follow-up of children born to seropositive mothers may in part explain these higher transmission rates reported, and vertical transmission rates reported in studies from Africa may not be a true representation of events in the developed world. There is no method by which intrauterine infection can be determined, but there are certain factors which may influence maternal-fetal transmission. Women with advanced HIV infection are more likely to infect their offspring (Hira et al. 1989; Ryder eta/. 1989), and breastfeeding plays a small but significant role in perinatal transmission. The pregnancy outcome, for both mother and baby, is not significantly different between H I V positive and matched HIV negative women (Selwyn 1989; Minkoff et a/. 1990a; European Collaborative Study 1991), although some groups have reported that babies born to seropositive women were more likely to be premature and of lower birth weight (Hira et al. 1989; Braddick eta/. 1990). The obstetric management of the HIV seropositive woman is little different to that of her seronegative counterpart but knowledge of her status allows close monitoring of the HIV infection and drug treatment to be instituted promptly if complications occur. It appears that pregnancy does not affect the course of H I V infection in the asymptomatic individual, but women with advanced HIV infection are at risk of severe opportunistic infections whilst pregnant (Minkoff et al. 1990b). These women benefit from antiretroviral therapy. Recent reports of the use of Zidovudine in pregnancy are reassuring as there have been n o fetal malformations, excess prematurity, or fetal toxicity attributed to the use of this drug in HIV infected women (Sperling et al. 1992). Knowing the
868
COMMENTARIES
status of the pregnant woman also allows the infant born to a seropositive mother to be monitored postnatally and followed-up appropriately by the paediatrician for evidence of acquired infection. With these advantages why is HIV screening controversial? The test cannot predict the transmission of HIV to the fetus. It can take 12 weeks for seroconversion to occur during which time the woman may be most infectious. A negative test at the beginning of pregnancy may not be indicative of HIV status at delivery and efforts must be made to emphasize methods of reducing new exposure to HIV infection. There is concern as there is no cure for HIV. Offering HIV testing may cause severe emotional distrcss but there is evidence that once a woman is found to have a negative test there is no further anxiety related to HIV status during the rest of the pregnancy (Larsson el al. 1990). It has been suggested that a negative test result gives permission for adopting risky behaviour. Worries regarding discrimination by life insurance companies on disclosure of an HIV test can now be allayed since their clear statement not to penalise those tcsted as part of an antenatal screening programme, providing the test is negative. Finally, there is the objection that implementing voluntary HIV screening to all pregnant women would result in an enormous increase in workload in antenatal clinics, require specialist HIV counsellors, and would not be cost effective in terms of the prevalence of HIV infection. The antenatal booking clinic provides the ideal opportunity to raise the issue of HIV testing at the same time as the other prenatal screening programmes which are routinely being performed. Counselling is not a new o r difficult skill for midwives and doctors responsible for the care of pregnant women. This pre-test HIV counselling should normally be short and unambiguous with the possibility of specialist HIVi AIDS counsellors available for specific cases in much the same way as referrals to specialist genetic counsellors are necessary. The use of written leaflets about HIV infection and AIDS are helpful but do not substitute for pre-test counselling (Sherr & Hedge 1990). The time between the test and result should be short. This should not create extra visits as the HIV result can be given at the same time as the results of the other investigations performed at the booking visit. A positive test result can be given with support from the HIVi AIDS counselling services. Any screening programme must be cost effective, acceptable to the public and ultimately reduce the disease prevalence. The cost of implementing routine antenatal testing must be weighed up against the prevalence of HIV infection both in the UK as a whole and in individual areas. With the seroprevalence of HIV infection outside London remaining stable at 1 in 16 000, there is no case for instituting HIV testing as a routine investigation. We would suggest that in these areas of low seroprevalence it should be discussed with women during their antenatal booking visit and only offered t o those who have an identified risk factor. However, in areas with higher seroprevalence, such as inner London, we believe it should now be offered routinely. Pre-test counselling
should be brief, given by a midwife who has undergone training and testing undertaken of those giving consent. By making HIV testing more routine and thus less stigmatising, more people will be aware of possible HIV infection and accept the case for routine screening. K. H. McCarthy Research Registrar in Obstetrics and Gynaecology". M. A. Johnson Consulant Physician in HIV/AIDS" J. W. W. Studd Consultant Obstetrician & Gynaecologisfi
Royal Free Hospital, Pond Street, London NW3 2QG Kings College Hospital, Denmark Hill, London SE5
References Adies A. E. et al. (1991). Prevalence of maternal HIV-1 infection in Thames regions: results from anonymous unlinked neonatal testing. Lancet 337, 1563-1565. Barbacci M., Rcpke J. T. & Chaisson R . E. (1991) Routine prenatal screening for HIV infection. Lancer 337,709-71 1 . Braddiek M. R. (199jl) Impact of maternal HIV infection on obstetrical and early neonatal outcome. A I D S 4, 1001-1005. European Collaborative Study (1991) Children born to women with HIV-1 infection: natural history and risk of transmission. Lance1 337,253-260.
Hira S. K. et al. (1989) Perinatal transmission of HIV-1 in Zambia. B M J 299, 1250-1252. Italian Multicentre Study (1988) Epidemiology, clinical features and prognostic factors of paediatric HIV infection. Lancet ii, 1043-1 045. Johnson M. A. & Webster A. (1990) Human immunodeficiency virus infection in women. In Progress in Obstetrics & Gynuecology, Vol. 8. (Studd J. ed.) Churchill Livingstone, Edinburgh, pp. 175-1 90. Larsson G., Spangberg L., Lindgren S. & Bohlin A. B. (1990) Screening for HIV in pregnant women: a study of maternal opinion. AIDS Care 2 ( 3 ) 223-225. Minkoff H. L. (1990a) Pregnancy outcomes among mothers infected with human immunodeficiency virus and uninfected control subjects. Am J Obstet Gynecol163, 1598-1604. Minkoff H . L. (1990b) Serious infections during pregnancy among women with advanced human immunodeficiency virus infection. A m J Obstet Gynecol162,3040. Norman S.. Studd J. W. W. &Johnson M. A. (1990) HIV infection in women. BMJ 301, 1231-1232. Ryder R. W., Nsa W., Hassig S. E. etal. (1989) Perinatal transmission of the human immunodeficiency virus type 1 to infants of seropositive mothers in Zaire. N Eng J Med 320,1637-1642. Selwyn P. A. (1989) Prospective study of human immunodeficiency virus infection and pregnancy outcomes in intravenous drug users. JAMA 261,1289-1294. Sherr L. & Hedge B. (1990) The impact and usc of written leaflets as a counselling alternative in mass antenatal HIV screening. A I D S Cure 2, ( 3 ) 235-244. Sperling R . S. (1992) A survey of Zidovudine use in pregnant women with human immunodeficiency virus infection. N EngI J Med 326, 857-861. Tappin D. M. (1991) Prcvalenee of maternal HIV infection in Scotland based on unlinked anonymous testing of newborn babies. Lancet 337, 1565-1567.
