Hiv Y Embarazo

C hapter 6: HIV in Pregnancy
By Jennifer Downing
Centre for Public Health, Liverpool John Moores University

The Global Challenge: prevention of HIV transmission from mother to child
Ed Wilkins
Consultant in GUM, North Manchester General Hospital
Nowhere is the beneficial impact of antiretroviral medication more emphatically made than in the successful
prevention of vertical transmissionof HIV. It is now 23 years since the first reported case of HIV in Manchester,
and 21 years since the first child was born to an infected mother. With developments in knowledge, monitoring
tests, and most importantly, antiretroviral drugs, the risk of transmission has gradually fallen to a level where the
discovery of HIV in a woman is no longer deemed a bar to future pregnancy. Theevidence-based information
has been achieved through clinical trials which have shown step-wise improvements in results with various drug
and dosing permutations of pre-natal, perinatal, and post-natal prophylaxis, with or without caesarean section.
With this has been the identification of obstetric and neonatal practices which have increased the risk of vertical
transmission, antiretroviral drugs thatcause maternal toxicity, and the potential for drug-induced teratogenicity
in the foetus.
In 2006, less than 10 percent of all mothers globally had access to adequate services to prevent mother-to-child
transmission (MTCT). Without intervention, the rate of vertical transmission is 25-44% in developing countries
and 13-25% in industrialised nations, a difference predominantly attributable tobreast feeding. Whereas MTCT
is now excessively rare in the indigenous populace in the west, it remains the cause of 90 percent of infections
in children in resource poor nations. This is despite the knowledge that Zidovudine alone started at 16 weeks
and continued in the neonate until six weeks after birth can reduce transmission by 70 percent and single dose
Nevirapine given to mothers duringlabour and to the neonate in the first 72 hours may also reduce transmission
by up to 44 percent. Using current Highly Active Antiretroviral Therapy (HAART) and starting from mid-second
trimester, the risk of vertical transmission, if the viral load is undetectable at time of delivery, is probably less
than one percent, irrespective of whether or not a caesarean section is performed.
Womenare pivotal for the wellbeing of a family. In developed countries, the risk of death for HIV-infected and
HIV-uninfected children is halved if the mother is alive. The means now exist to prevent MTCT in the majority of
children through maternal screening and appropriate prophylaxis to mother and child. In Greater Manchester,
approximately 50 pregnancies are now occurring annually in HIV-infectedwomen and are being successfully
managed through a multidisciplinary network. By far the majority of these are women from sub-Saharan Africa
who are diagnosed antenatally through antibody screening. The last quarter of a century has seen unparalleled
advances in HIV management with a previously inevitably fatal condition becoming a chronic illness with a nearnormal life expectancy and withvertical transmission becoming a rarity. The challenge for the next 25 years is to
deliver the infrastructure and the antiretrovirals to the areas of the world which are currently without, thereby
preventing the next generation becoming infected with HIV at birth.

82

Ten Years of Monitoring HIV & AIDS in the North West of England

Introduction
HIV prevalence in women has increasedsubstantially in the last ten years, with women now representing 31% of
all HIV cases in the UK1. In 1999, the Department of Health issued a health service circular to Health Authorities in
order to ensure that all pregnant women were offered and recommended an HIV test as part of their antenatal care
by 20002, with the intention that there would be a 90% national uptake of testing to identify 80% of...