HIV treatment centres in the UK are overwhelmingly taking appropriate action to prevent mother-to-baby transmission of HIV, according to an audit of practices published in the website of the British HIV Association. However, the audit did find some areas where clinics could benefit from clear guidelines, including the use of specific antiretroviral drugs during pregnancy, the circumstances where a planned vaginal birth might be appropriate, and the management of women who decide to breast-feed their infants.
The British HIV Association has comprehensive pregnancy guidelines, and a survey was conducted of the management of HIV maternal care involving a case review of pregnancies ending in live or still birth between October 2002 and September 2003.
A total of 80 treatment centres submitted data for 504 pregnancies. The overwhelming majority of centres worked as part of a local multi-disciplinary team which involved HIV physicians and obstetricians, an arrangement which was found to be satisfactory by nearly all centres.
HIV was diagnosed either before pregnancy or during the first or second trimester of pregnancy in 92% of women. In only 1% of cases was HIV diagnosed either less than seven days before delivery or post-delivery.
At the start of pregnancy 76% of women had a CD4 cell count above 200 cells/mm3, and 21% of women were already taking anti-HIV medication before pregnancy, of these 79% had a viral load below 50 copies/ml and a further 13% of a viral load between 50-500 copies/ml.
A wide variety of antiretroviral therapy was being used by women before pregnancy, with 10% of individuals taking a HAART regimen based on the NNRTI efavirenz (efavirenz is contraindicated in pregnancy due to the potential for foetal abnormalities if the unborn child is exposed to the drug during gestation, especially the first trimester).
Antiretroviral therapy was used by a total of 484 women during pregnancy. The most widely used HAART regimen was AZT, 3TC, nevirapine (50% of women). AZT monotherapy was used by 14% of women. Just over a third of centres reported that in subsequent pregnancies, their choice of antiretrovirals would be guided by resistance tests and adherence to previous HAART combinations. However, 20% of centres said they would use the standard, recommended regimen or use the same regimen as in previous pregnancies.
Caesarean deliveries were planned for 422 (85%) births. In 43 cases (9%) a vaginal delivery was planned, and in all but five cases the maternal HIV viral load was below 50 copies/ml. Caesarean delivery was used for 81% of births and 11% of births were vaginal, data being missing for the other 8%.
Centres varied greatly in their approaches to bottle-feeding. When asked to state how they would approach a situation where a mother insisted on breastfeeding seven centres said that this was a matter of parental choice, 14 centres said child welfare would be their first priority, 21 centres said they would aim to keep maternal viral load below 50 copies/ml, 15 centres said they would advise exclusive breastfeeding, four centres suggested continued antiretroviral therapy for the baby, and three thought boiling breast milk would be an option.
"While broadly positive, this audit has shown a number of areas where clear guidance may be needed,” conclude the audit committee. These include the use of antiretrovirals during pregnancy, particularly the appropriate cessation of efavirenz therapy.
Further information
BHIVA- the pregnancy audit and current guidelines can be downloaded from the website of the British HIV Association.