Mother-to-child transmission of HIV

Export Indicator

Estimated percentage of children newly infected with HIV from mother-to-child transmission among women living with HIV delivering in the past 12 months
What it measures

Progress in providing women with antiretroviral medicines to reduce mother-to-child transmission of HIV

Rationale

Efforts have been made to increase access to interventions that can significantly reduce mother-to-child transmission of HIV, including combining antiretroviral medicine prophylactic and treatment regimens and strengthening counselling on infant feeding. The impact of interventions for preventing mother-to-child transmission in reducing the number of children newly infected with HIV through mother-to-child transmission needs to be assessed.

The percentage of children who are living with HIV should decrease as the coverage of interventions for preventing mother-to-child transmission and the use of more effective regimens increase.

Numerator

Estimated number of children newly infected with HIV from mother-to-child transmission among children born in the previous 12 months to women living with HIV

Denominator

Estimated number of children delivered by women living with HIV who delivered in the previous 12 months

Calculation

Numerator/denominator

Method of measurement

The probability of mother-to-child transmission differs with the antiretroviral drug regimen received and infant-feeding practices. The transmission can be calculated using Spectrum. The Spectrum computer programme uses information on: 

  • The distribution of pregnant women living with HIV receiving different antiretroviral regimens before and during delivery (peripartum) by the CD4 category of the mother. 
  • The distribution of women and children receiving antiretroviral medicines after delivery (postpartum) by the CD4 category of the mother. 
  • The percentage of infants who are not breastfeeding in programmes for preventing mother-to-child transmission by the age of the child. 
  • Probabilities of mother-to-child transmission of HIV based on various categories of antiretroviral medicine regimen and infant feeding practices. 
  • The estimated number of women living with HIV delivering.

The summary display for preventing mother-to-child transmission in Spectrum reports the estimated national transmission rate. This variable can also be calculated in Spectrum by dividing the number of children 0–14 years old newly infected with HIV by the number of women who need services for preventing mother-to-child transmission.

Not enough information is available about other HIV transmission routes for children to include such infections in the model. In addition, other modes of transmission are believed to cause a small fraction of the overall number of children acquiring HIV. The Spectrum output variable “new HIV infections for children 0–1 years” is not used because some children older than one year will acquire HIV from breastfeeding.

To ensure comparability, the Spectrum output will be used for calculating this indicator for global analysis.

Users have the option to use their Spectrum estimate or to enter nationally representative population-level data. If Spectrum estimates are chosen, the values will be pulled directly from the software once the national file is finalized. If programme data are included, report the data based on equal birth cohorts for the numerator and denominator and not by the year of diagnosis.

Measurement frequency

Annually

Disaggregation

None

Additional information requested

To ensure comparability, the Spectrum output will be used for calculating this indicator for global analysis.

If programme data are used, report the data based on equal birth cohorts for numerator and denominator and not by the year of diagnosis.

Users have the option to use their Spectrum estimate or to enter nationally representative population-level data. If Spectrum estimates are chosen, the values will be pulled directly from the software once the national file is finalized.

Strengths and weaknesses

Strengths. Over time, this indicator assesses the ability of programmes for preventing mother-to-child transmission by estimating the impact of increases in the provision of antiretroviral medicines and the use of more efficacious regimens and optimal infant feeding practices. This indicator allows countries to assess the impact of antiretroviral medicine programmes on the number of children acquiring HIV by estimating the HIV transmission rate from women living with HIV to their children. The modelled estimate enables this value to be estimated since capturing this indicator through direct measures is almost impossible. The modelled estimate overcomes three challenges.

1. Following up mother–child pairs is difficult, especially at the national level, because of the lag in reporting and the multiple health facility sites that mother–child pairs can visit for the wide range of services for preventing mother-to-child transmission and child care interventions delivered over a time span.

2. Children (especially those living with HIV) may die before they are tested to determine whether transmission occurred.

3. A directly measured indicator will not capture women and their children who do not attend programmes, possibly because of high levels of stigma.

Weaknesses. This indicator is generated from a model that provides estimates of HIV infection among children. The estimated indicator is only as good as the assumptions and data used in the model. In countries where caesarean section is widely practised, the indicator will overestimate motherto-child transmission. It also relies on programme data that often capture the antiretroviral medicine regimens provided rather than those consumed and could therefore underestimate mother-to-child transmission.

This indicator does not capture efforts to reduce the risk of mother-to-child transmission by reducing the number of reproductive-age women acquiring HIV or by reducing unintended pregnancies among women living with HIV.

In countries in which data are available, facility attendance is high and confirmatory tests are conducted systematically, efforts should be made to monitor the impact by directly assessing the percentage of children living with HIV among those born to mothers living with HIV. All countries should make efforts to monitor the HIV status and survival of children born to women living with HIV, gathered during follow-up health-care visits.

Further information

WHO publications on HIV monitoring and evaluation (http://www.who.int/hiv/pub/me/en/index.html).