Poster P160
Among migrant African women, increased duration of stay
in the UK or Ireland reduces the risk of detectable maternal
HIV viral load at delivery
1,2
Tariq ,
Shema
Mario Cortina Borja2,
2
1
Jonathan Elford , Pat A Tookey
1 City
University London; 2 MRC Centre of Epidemiology for Child Health, UCL Institute of Child Health
Introduction
Methods
• Over 80% of women diagnosed with HIV giving birth in the UK & Ireland are
from sub-Saharan Africa (SSA).
An analysis of data from:
National Study of HIV in Pregnancy and Childhood (NSHPC)
• Confidential comprehensive population-based surveillance since 1989.
• Main respondents are from maternity units in the United Kingdom & Ireland.
• New migrants have specific barriers in accessing healthcare including:
language; discrimination; lack of knowledge of systems; and poverty 1,2,3.
• Detectable maternal viral load at delivery (VL) is strongly associated with
increased risk of MTCT4 and may preclude vaginal delivery.
• There have been no UK studies to date exploring the association between time
since migration and clinical outcomes in pregnant women diagnosed with HIV.
Aim: To describe the association of maternal duration of stay in
the UK/Ireland with:
(i) detectable maternal HIV viral load (VL) at delivery and
(ii) MTCT
in pregnancies among women with HIV born in SSA.
• We included all live singleton births and still births between 2000 and 2009 in
diagnosed HIV-infected women of black or mixed ethnicity who were born in
SSA.
• Analysis of VL and MTCT was restricted to pregnancies where the mother was
prescribed HAART.
• VL at delivery: the latest available VL in pregnancy ≤28 days before or ≤ after
delivery.
• Duration of stay: years between date of mother’s entry into UK/Ireland and
estimated date of conception.
• Logistic regression models were fitted, with mixed effects where appropriate.
Results
Duration of stay in UK
Baseline characteristics*: Table 1
• 7139 pregnancies in women from SSA were reported between 2000 and 2009.
• 4437 pregnancies had available data on maternal duration of stay
Median maternal duration of stay in UK in years (IQR)
(N=3491)
Region of origin†
East Africa
Southern Africa
West Africa
Middle Africa
4.0 (1.9, 6.6)
2.1 (0.5, 4.0)
2.9 (0.8, 5.8)
2.9 (0.5, 6.1)
<25
25-34
≥35
2.0 (0.2, 3.5)
3.2 (1.3, 5.8)
5.6 (2.9, 9.1)
Before pregnancy
During pregnancy
4.9 (2.7, 7.3)
1.7 (0.2, 4.1)
≥500
200-499
<200
3.8 (1.7, 6.6)
3.6 (1.4, 6.2)
3.1 (0.8, 6.1)
Initial viral load (copies/ml)†
Undetectable
50-999
1000-9999
≥10000
4.8 (2.4, 7.5)
3.1 (1.2, 5.8)
3.2 (1.3, 6.0)
3.2 (1.2, 5.8)
Duration of HAART (weeks)†
≥40
12-40
<12
5.4 (3.1, 8.1)
3.2 (1.2, 5.6)
1.8 (0.1, 4.3)
Elective CS
Emergency CS
Vaginal
3.4 (1.2, 6.2)
3.7 (1.5, 6.5)
3.4 (1.3, 6.1)
≥ 37
34-36
32-34
<34
3.5 (1.3, 6.2)
3.7 (1.4, 6.8)
3.2 (1.4, 6.9)
4.0 (1.5, 6.2)
• Median maternal duration of stay was 3.5 years (interquartile range 1.3, 6.3).
• Maternal duration of stay increased over time from 1.9 to 5.8 years (p<0.001).
Fig 1: Median maternal duration of stay in UK/Ireland at conception over time
(restricted to 1st reported pregnancy to NSHPC)
Maternal age at delivery (years)†
When diagnosed†
Initial CD4 (cells/mm3)†
Mode of delivery ‡
Gestational age (weeks) ‡
* Restricted to pregnancies in which women were prescribed HAART.
† p<0.001; ‡ p>0.1; p values obtained with Kruskal-Willis test; IQR, interquartile range; CS, caesarean section..
Maternal and infant outcomes: Table 2
Conclusions
MTCT
(n=3041)
OR per year increase in
duration of stay (95% CI)
0.84 (0.74, 0.95)
p
Univariable
Detectable maternal VL at delivery
(n=2092)
OR per year increase in
p
duration of stay (95% CI)
0.90 (0.86,0.93)
<0.001
Multivariable*
0.96 (0.93, 0.99)
0.95 (0.79, 1.02)
0.110
<0.001
0.007
* Adjusted for year of delivery, maternal age and duration of HAART; OR, odds ratio; CI, confidence interval.
Missing data
• 38% of pregnancies did not have maternal date of arrival in UK/Ireland reported.
• There was no association between missing maternal duration of stay and either
detectable VL at delivery or MTCT (p>0.5).
• Date of arrival was more commonly missing in pregnancies reported outside
London than in those reported in London (56.5% vs. 35.4%, p<0.001).
Acknowledgements: Thank you to all obstetric and paediatric respondents to the NSHPC.
NSHPC team: Pat Tookey (PI), Janet Masters, Hiwot Haile-Selassie, Clare French, Icina Shakes.
Contact : nshpc@ich.ucl.ac.uk Website www.nshpc.ucl.ac.uk
Ethics & funding: Shema Tariq is funded by a UK Medical Research Council (MRC) Fellowship
(G0701648). The Centre for Paediatric Epidemiology and Biostatistics benefits from funding support
from the Medical Research Council in its capacity as the MRC Centre of Epidemiology for Child
Health. The NSHPC is funded by the Health Protection Agency. It has London Multi-Centre
Research Ethics Committee approval (MREC/04/2/009).
• Median maternal duration of stay in the UK/Ireland at conception
has increased over time (Fig 1).
• Among pregnant women from SSA who have been prescribed
HAART, the risk of detectable VL at delivery decreased by 4% with
each additional year of stay. MTCT risk was not affected by
duration of stay (Table 2).
• This analysis was limited by poor reporting of date of arrival in the
UK/Ireland which may bias our results.
• Further work is needed to elucidate the complex socio-economic
factors that may underlie the association between migration and
virological control, in order to identify appropriate interventions.
References:
1. Rajamanoharan, S., at al. 2004. "Genitourinary medicine/HIV services for persons with insecure immigration or
seeking asylum in the United Kingdom: a British Co-operative Clinical Group survey." Int J STD AIDS 15(8):509-514.
2. NSHPC et al. 2007. "Perinatal transmission of HIV in England 2002-2005: Executive summary”.
3. Johnson, M. 2006. "Integration of new migrants." In Refugees and other new migrants: A review of the evidence on
successful approaches to integration., ed. S. Spencer. London: Home Office.
4. Warszawski, J ., et al. 2008. "Mother-to-child HIV transmission despite antiretroviral therapy in the ANRS French
Perinatal Cohort." AIDS 22(2):289-299.
Correspondence to:
Shema Tariq
City University London
20 Bartholomew Close
London, EC1A 7QN
Email: shema.tariq.2@city.ac.uk