***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVES The aim of this study was to investigate the possible effects of antiretroviral therapy ( ART ) in utero on cardiac development and function in human immunodeficiency virus (HIV)-negative children . BACKGROUND ART reduces vertical HIV transmission . Long-term cardiotoxicity after in utero exposure to ART is unknown in children but has occurred in young animals . METHODS Using a prospect i ve multisite cohort study design , echocardiograms taken between birth and 24 months were compared in 2 groups of HIV-negative infants of HIV-positive mothers : 136 infants exposed to ART ( ART+ ) and 216 unexposed infants ( ART- ) . RESULTS Mean left ventricular ( LV ) mass z-scores were consistently lower in ART+ girls than in ART- girls : differences in mean z-scores were -0.46 at birth ( p = 0.005 ) , -1.02 at 6 months ( p < 0.001 ) , -0.74 at 12 months ( p < 0.001 ) , and -0.79 at 24 months ( p < 0.001 ) . Corresponding differences in z-scores for boys were smaller : 0.13 at 1 month ( p = 0.42 ) , -0.44 at 6 months ( p = 0.01 ) , -0.15 at 12 months ( p = 0.37 ) , and -0.21 at 24 months ( p = 0.21 ) . Septal wall thickness and LV dimension were smaller than expected in ART+ infants , but LV contractility was consistently about 1 SD higher at all ages ( p < 0.001 ) . In ART+ infants , LV fractional shortening was higher than in ART- infants ; girls showed a greater difference . CONCLUSIONS Fetal exposure to ART is associated with reduced LV mass , LV dimension , and septal wall thickness z-scores and increased LV fractional shortening and contractility up to age 2 years . These effects are more pronounced in girls than in boys . Fetal ART exposure may impair myocardial growth while improving depressed LV function CONTEXT Antenatal counseling and human immunodeficiency virus ( HIV ) testing are not universal in Africa ; thus , women often present in labor with unknown HIV status without receiving the HIVNET 012 nevirapine ( NVP ) regimen ( a single oral dose of NVP to the mother at the start of labor and to the infant within 72 hours of birth ) . OBJECTIVE To determine risk of mother-to-child transmission of HIV when either st and ard use of NVP alone or in combination with zidovudine ( ZDV ) was administered to infants of women tested at delivery . DESIGN , SETTING , AND PARTICIPANTS A r and omized , open-label , phase 3 trial conducted between April 1 , 2000 , and March 15 , 2003 , at 6 clinics in Blantyre , Malawi , Africa . The trial included all infants born to 894 women who were HIV positive , received NVP intrapartum , and were previously antiretroviral treatment-naive . Infants were r and omly assigned to NVP ( n = 448 ) and NVP plus ZDV ( n = 446 ) . Infants were enrolled at birth , observed at 6 to 8 weeks , and followed up through 3 to 18 months . The HIV status of 90 % of all infants was established at 6 to 8 weeks . INTERVENTION Mothers received a 200-mg single oral dose of NVP intrapartum and infants received either 2-mg/kg oral dose of NVP or NVP ( same dose ) plus 4 mg/kg of ZDV twice per day for a week . MAIN OUTCOME MEASURES HIV infection of infant at birth and 6 to 8 weeks , and adverse events . RESULTS The mother-to-child transmission of HIV at birth was 8.1 % ( 36/445 ) in infants administered NVP only and 10.1 % ( 45/444 ) in those administered NVP plus ZDV ( P = .30 ) . A life table estimate of transmission at 6 to 8 weeks was 14.1 % ( 95 % confidence interval [ CI ] , 10.7%-17.4 % ) in infants who received NVP and 16.3 % ( 95 % CI , 12.7%-19.8 % ) in those who received NVP plus ZDV ( P = .36 ) . For infants not infected at birth and retested at 6 to 8 weeks , transmission was 6.5 % ( 23/353 ) in those who received NVP only and 6.9 % ( 25/363 ) in those who received NVP plus ZDV ( P = .88 ) . Almost all infants ( 99%-100 % ) were breastfed at 1 week and 6 to 8 weeks . Grade s 3 and 4 adverse events were comparable ; 4.9 % ( 22/448 ) and 5.4 % ( 24/446 ) in infants receiving NVP only and NVP plus ZDV , respectively ( P = .76 ) . CONCLUSIONS The frequency of mother-to-child HIV transmission at 6 to 8 weeks in our 2 study groups was comparable with that observed for other perinatal HIV intervention studies among breastfeeding women in Africa . The safety of the regimen containing neonatal ZDV was similar to that of a st and ard NVP regimen BACKGROUND The most effective highly active antiretroviral therapy ( HAART ) to prevent mother-to-child transmission of human immunodeficiency virus type 1 ( HIV-1 ) in pregnancy and its efficacy during breast-feeding are unknown . METHODS We r and omly assigned 560 HIV-1-infected pregnant women ( CD4 + count , > or = 200 cells per cubic millimeter ) to receive coformulated abacavir , zidovudine , and lamivudine ( the nucleoside reverse-transcriptase inhibitor [ NRTI ] group ) or lopinavir-ritonavir plus zidovudine-lamivudine ( the protease-inhibitor group ) from 26 to 34 weeks ' gestation through planned weaning by 6 months post partum . A total of 170 women with CD4 + counts of less than 200 cells per cubic millimeter received nevirapine plus zidovudine-lamivudine ( the observational group ) . Infants received single-dose nevirapine and 4 weeks of zidovudine . RESULTS The rate of virologic suppression to less than 400 copies per milliliter was high and did not differ significantly among the three groups at delivery ( 96 % in the NRTI group , 93 % in the protease-inhibitor group , and 94 % in the observational group ) or throughout the breast-feeding period ( 92 % in the NRTI group , 93 % in the protease-inhibitor group , and 95 % in the observational group ) . By 6 months of age , 8 of 709 live-born infants ( 1.1 % ) were infected ( 95 % confidence interval [ CI ] , 0.5 to 2.2 ) : 6 were infected in utero ( 4 in the NRTI group , 1 in the protease-inhibitor group , and 1 in the observational group ) , and 2 were infected during the breast-feeding period ( in the NRTI group ) . Treatment-limiting adverse events occurred in 2 % of women in the NRTI group , 2 % of women in the protease-inhibitor group , and 11 % of women in the observational group . CONCLUSIONS All regimens of HAART from pregnancy through 6 months post partum result ed in high rates of virologic suppression , with an overall rate of mother-to-child transmission of 1.1 % . ( Clinical Trials.gov number , NCT00270296 . BACKGROUND The AIDS Clinical Trials Group protocol 076 zidovudine prophylaxis regimen for HIV-1-infected pregnant women and their babies has been associated with a significant decrease in vertical HIV-1 transmission in non-breastfeeding women in developed countries . We compared the safety and efficacy of short-course nevirapine or zidovudine during labour and the first week of life . METHODS From November , 1997 , to April , 1999 , we enrolled 626 HIV-1-infected pregnant women at Mulago Hospital in Kampala , Ug and a. We r and omly assigned mothers nevirapine 200 mg orally at onset of labour and 2 mg/kg to babies within 72 h of birth , or zidovudine 600 mg orally to the mother at onset of labour and 300 mg every 3 h until delivery , and 4 mg/kg orally twice daily to babies for 7 days after birth . We tested babies for HIV-1 infection at birth , 6 - 8 weeks , and 14 - 16 weeks by HIV-1 RNA PCR . We assessed HIV-1 transmission and HIV-1-free survival with Kaplan-Meier analysis . FINDINGS Nearly all babies ( 98.8 % ) were breastfed , and 95.6 % were still breastfeeding at age 14 - 16 weeks . The estimated risks of HIV-1 transmission in the zidovudine and nevirapine groups were : 10.4 % and 8.2 % at birth ( p=0.354 ) ; 21.3 % and 11.9 % by age 6 - 8 weeks ( p=0.0027 ) ; and 25.1 % and 13.1 % by age 14 - 16 weeks ( p=0.0006 ) . The efficacy of nevirapine compared with zidovudine was 47 % ( 95 % CI 20 - 64 ) up to age 14 - 16 weeks . The two regimens were well tolerated and adverse events were similar in the two groups . INTERPRETATION Nevirapine lowered the risk of HIV-1 transmission during the first 14 - 16 weeks of life by nearly 50 % in a breastfeeding population . This simple and inexpensive regimen could decrease mother-to-child HIV-1 transmission in less-developed countries Context : The Women and Infants Transmission Study is a prospect i ve natural history study that has been enrolling HIV‐1‐infected pregnant women and their infants since 1989 . Objective : Toevaluate the impact of different antiretroviral regimens on perinatal HIV‐1 transmission at the population level . Design : Prospect i ve cohort study . Plasma HIV‐1 RNA levels were serially measured in 1542 HIV‐1‐infected women with singleton live births between January 1990 and June 2000 . Main Outcome Measure : HIV‐1 status of the infant . Results : HIV‐1 transmission was 20.0 % ( 95 % confidence interval [ CI ] , 16.1%‐ 23.9 % ) for 396 women who not receiving prenatal antiretroviral therapy ; 10.4 % ( 95 % CI , 8.2%‐12.6 % ) for 710  receiving zidovudine monotherapy ; 3.8 % ( 95 % CI , 1.1%‐ 6.5 % ) for 186 receiving dual antiretroviral therapy with no or one highly active drug ( Multi‐ART ) ; and 1.2 % ( 95 % CI , 0‐2.5 % ) for 250 receiving highly active antiretroviral therapy ( HAART )  . Transmission also varied by maternal delivery HIV RNA level : 1.0 % for < 400 ; 5.3 % for 400 to 3499 ; 9.3 % for 3500 to 9999 ; 14.7 % for 10,000 to 29,999 ; and 23.4 % for > 30,000 copies/mL ( p = .0001 for trend ) . The odds of transmission increased 2.4‐fold ( 95 % CI , 1.7‐3.5 ) for every log10 increase in delivery viral load . In multivariate analyses adjusting for maternal viral load , duration of therapy , and other factors , the odds ratio for transmission for women receiving Multi‐ART and HAART compared with those receiving ZDV monotherapy was 0.30 ( 95 % CI , 0.09‐1.02 ) and 0.27 ( 95 % CI , 0.08‐0.94 ) , respectively . Conclusion : Levels of HIV‐1 RNA at delivery and prenatal antiretroviral therapy were independently associated with transmission . The protective effect of therapy increased with the complexity and duration of the regimen . HAART was associated with the lowest rates of transmission Zidovudine prophylaxis is recommended to reduce perinatal HIV-1 transmission , but there are limited data on long-term effects on women 's health . Pediatrics AIDS Clinical Trials Group ( PACTG ) 288 was a prospect i ve observational study among US women r and omized to zidovudine or placebo in PACTG 076 that was design ed to evaluate and compare postpartum clinical , immune , and viral parameters between r and omized treatment arms . Forty-eight percent ( 226/474 ) of eligible women 
    Output:
    
New cohort studies found antiretroviral therapy during pregnancy to be associated with increased risk for preterm delivery ( < 37 weeks ' gestation ) ; there were no clear associations with low birthweight , congenital abnormalities , or infant neurodevelopment .
CONCLUSION Antiretroviral therapy in combination with avoidance of breastfeeding and elective cesarean section in women with viremia reduces risk for mother-to-child transmission .
Use of certain antiretroviral therapy regimens during pregnancy may increase risk for preterm delivery .