MoCHiV key data (figures)

1. State of the MoCHiV cohort

The Swiss Mother and Child HIV Cohort Study (MoCHiV) was started in 2003 as a combined study of two former studies ‘Neonatal HIV Study’ and ‘HIV Pregnancy Study’. The final aim was the integration into the existing Swiss HIV Cohort Study (SHCS). Since then, as in the SHCS, a large biobank exists for all enrolled children. MoCHiV aims at preventing mother-to-child transmission and enrolls HIV-infected pregnant women and their children.

Since the beginning of the HIV epidemic in the early 1980’s until 2023, data of 2'209 children - of whom 280 were living with HIV - have been registered into MoCHiV. Of the children living with HIV, 81 were lost from follow-up or are treated by a non-cohort physician, 62 have died, and 35 are currently under follow-up in MoCHiV. 102 children reached adulthood and are now followed by the SHCS (fig. 1). Most of the children living with HIV currently under follow-up are treated with a combined antiretroviral therapy. Of the HIV negative children, 157 children are currently under follow-up. They are planned to be followed for at least 2 years.

 



fig. 1: Overview of MoCHiV participating children - update 2023

Initially, no intervention at all was available to reduce vertical transmission. Transmission rates were in the range between 20 - 25%. Later on, preventive interventions became available. First antiretroviral monotherapy with Zidovudine, then combined with elective cesarean section (ECS) were the first steps to prevent vertical transmission. Then ECS in combination with highly active antiretroviral therapy (HAART) was considered as the prevention of choice for vertical transmission of HIV. Since the HIV treatment is more successful within the last few years, the guidelines could be adjusted. According to the current guidelines, vaginal delivery is proposed if the woman is under a stable therapy and no virus can be detected in her blood (fig. 2).


fig. 2: Mode of delivery in women living with HIV

The evolution of preventive interventions has been very successful. Vertical transmission rate could steadily and substantially be reduced. In the last few years, no cases of transmission were registered in MoCHiV. The definitive diagnoses can be made after four to six months based on two diagnostic blood samples taken one month and four to six months after birth (fig. 3).

 

Figure 3: HIV Status of children born to HIV positive mothers
fig. 3: HIV status of children born to women living with HIV
 
 

2. Mothers in the MoCHiV

Mothers are recruited largely from the heterosexual transmission group (79.3%). A small part of women was infected by HIV-contaminated needles during drug use (IDU). Thanks to the successful HIV-treatment some women who were perinatally infected in the 80’s and 90’s reach now the adulthood and can give birth without vertical transmission (fig. 4). 



Figure 4: Transmission of HIV in mothers
fig. 4: HIV transmission group of mothers

Most of the women included in the MoCHiV until 2023 (66.3%) were already treated before pregnancy, 5.5% started antiretroviral therapy in the first trimester of pregnancy, 19.9% in the second, 7.4% in the third trimester, and 0.8% were not treated. Twenty-four percent of women (N=178) received additional AZT prophylaxis during delivery (fig. 5).