HAART use among women in UK receiving treatment prior to conception

HIV positive women in the UK are increasingly receiving HAART prior to conception and pregnancy.

BHIVA guidelines recommend that women already on treatment at conception remain on HAART throughout and after their pregnancy.

Some drugs, notably efavirenz (EFV), are not recommended for use during pregnancy.

Loveleen Bansi and colleagues from the UK CHIC Study and the National Study of HIV in Pregnancy and Childhood (NSHPC) analysed clinical and treatment patterns of women conceiving their first child on HAART between 1996 and 2008 using linked data from the two datasets.

The investigators found 1838 matches between the women in the current UK CHIC (n=8,659) and NSHPC (10,912) datasets. Of these, 821 (45%) had received HIV clinical care before their first pregnancy.

The majority of women were infected via heterosexual sex (88%) and over two-thirds (69%) were of black-African ethnicity. Their median age at delivery was 33 (IQR: 28-36) years.

Just over half, 440/821 (54%) women were receiving HAART at the time of conception of their first child.

Their median CD4 count at conception was 389 (IQR 270-554) cells/mm3. Amongst women who had a measurement up to 90 days before conception, 88 (27.9%) had a detectable viral load >50copies/mL.

Of the 440 women, 237 (53.9%) received an NNRTI and for 86 (19.5%) women this was EFV. Most women had not started treatment close to conception, 40.9% had already been on HAART for over 3 years and only 10.9% started less than 6 months before conceiving.

One-third (n=155 (35.2%)) made a switch in their regimen before delivery. The proportions of women switching therapy by 3 and 6 months of conception were 22% and 33%. Of those receiving EFV at conception, 37 (43%) of women switched this drug.

The vast majority (97%) of women receiving HAART at conception were also receiving HAART at delivery. After delivery 286/428 women switched regimen at a median of 15 (IQR 13-18) months.

The proportions of women switching regimen at 6, 12, 18 and 24 months were 27%, 41%, 55% and 61%, respectively. In the year following delivery 13 (13%) of women receiving HAART at delivery discontinued completely.

The investigators wrote; Adherence support is important after pregnancy to minimise the number who interrupt or stop treatment after delivery.

comment

The authors of this poster noted (personal correspondence) that they dont have information on when the woman found out she was pregnant, in relation to conception (or when she told her clinician). So, for women who were already on efavirenz at the time of conception, if they didnt find out they were pregnant until a few months into the pregnancy, it might be argued that any potential damage had already been done, and so there was less reason to switch.

Ref: Bansi L et al. Use of antiretroviral therapy during and after pregnancy among HIV-infected women already aware of their infection before conceiving. 2nd Joint Conference of BHIVA with BASHH, 2023 April 2010, Manchester. Poster abstract P154.