Risk Factors for Maternal Transmission of HIV-1 to Infants

 

Risk of transmitting HIV-1:

(1) women with (at least 1 negative culture) AND (high CD4 cell percentage or low CD8 cell percentage) were at very low risk (0-4%) for transmission

(2) women with (always positive cultures) transmitted at a high rate regardless of immune status (18-27%)

 

Lymphocyte counts expressed as quartile:

(1) quantification of maternal lymphocyte phenotypes was expressed using percentages rather than absolute counts to minimize the impact of variability of leukocyte counts during pregnancy and delivery

(2) The lymphocyte percentage was then compared to the quartiles for the normal reference population, from 1 (lowest) to 4 (highest).

Finding	Value	Parameter
CD4 cell percent quartile	1, 2, 3, 4	-0.48
CD8 cell percent quartile	1, 2, 3, 4	0.57
HIV culture positivity	0 = not always; 1 = always	2.58
(CD8 cell percent quartile) * (HIV culture positivity)	0, 1, 2, 3, 4	-0.83
duration of ruptured membranes at delivery	< 4 hours: 1 4-23.9 hours: 2 >= 24 hours: 3	0.67
drug use (intravenous drugs, methadone, cocaine)	no: 2 yes: 1	0.73
constant	1	-0.425

 

total score =

= SUM ((value) * (parameter))

 

risk of HIV-1 transmission =

= 1 / (1 + EXP ((-1) * (total score)))

 

Limitations:

• It has been shown subsequently that treating the mother with antiretroviral agents reduces the transmission of HIV to the infant. The impact of this is not included in this data.