Study of Effects of Tenofovir on Bone Health and Kidneys During Pregnancy and Breastfeeding

• Antepartum Component: Creatinine clearance (CrCl) [ Time Frame: For women and infants: at delivery/birth, up to Week 1 ] [ Designated as safety issue: No ]
  
• Antepartum Component: Bone resorption (Dpyr) [ Time Frame: For women and infants: at delivery/birth, up to Week 1 ] [ Designated as safety issue: No ]
  
• Antepartum Component: Lumbar spine bone mineral density (BMD) via dual energy e-ray absorptiometry (DXA) [ Time Frame: For women: at delivery/birth, up to Week 1 ] [ Designated as safety issue: No ]
  
• Antepartum Component: Lumbar spine bone mineral content (BMC) and whole body BMC via DXA [ Time Frame: For infants: at delivery/birth, up to Week 1 ] [ Designated as safety issue: No ]
  
• Antepartum Component: Length-for-age Z-score [ Time Frame: For infants: at delivery/birth, up to Week 1 and Week 26 ] [ Designated as safety issue: No ]
  
• Postpartum Component: CrCl [ Time Frame: For women: at postpartum entry (delivery/birth, up to Week 1) and Week 74; for infants: at Week 26 ] [ Designated as safety issue: No ]
  
• Postpartum Component: Dpyr [ Time Frame: For women: at Week 74; for infants: at Week 26 ] [ Designated as safety issue: No ]
  
• Postpartum Component: Lumbar spine BMD via DXA [ Time Frame: For women: at postpartum entry (delivery/birth, up to Week 1) and Week 74 ] [ Designated as safety issue: No ]
  
• Postpartum Component: Lumbar spine BMC via DXA [ Time Frame: For infants: at Week 26 ] [ Designated as safety issue: No ]
  
• Postpartum Component: Length-for-age Z-score [ Time Frame: For infants: at postpartum entry (delivery/birth, up to Week 1) and Week 26 ] [ Designated as safety issue: No ]
  

• CrCl [ Time Frame: For women: Weeks 6, 26, and 74; for infants: at Weeks 10, 26, and 74 ] [ Designated as safety issue: No ]
  
• BMD [ Time Frame: For women: at delivery and change in hip BMD from delivery to Week 74 ] [ Designated as safety issue: No ]
  
• Dpyr [ Time Frame: For women: at Weeks 6, 26, and 74; for infants: at Weeks 10, 26, and 74 ] [ Designated as safety issue: No ]
  
• Mineral composition of breast milk [ Time Frame: For women: at Weeks 1, 6, 26, and 74 ] [ Designated as safety issue: No ]
  
• Lumbar spine BMC [ Time Frame: For infants: Week 26 ] [ Designated as safety issue: No ]
  
• Infant growth [ Time Frame: For infants: at Weeks 10 and 74 ] [ Designated as safety issue: No ]
  
• Concentration of hormonal growth factors (for infants) [ Time Frame: For infants: at birth and Weeks 10, 26, and 74 ] [ Designated as safety issue: No ]
  

A small number of adults (who are not pregnant) and children who take anti-HIV medications develop problems with their kidneys and with the strength of their bones. These problems may be more common when tenofovir disoproxil fumarate (TDF) is used. Studies about these bone and kidney effects have not been done in pregnant and breastfeeding women and their infants.

This is a substudy of a larger study (IMPAACT 1077 PROMISE [Promoting Maternal and Infant Survival Everywhere]) to evaluate the safety of anti-HIV medications used in pregnancy and during breastfeeding. Only participants in the larger study randomly assigned to receive maternal tenofovir disoproxil fumarate (TDF) or no maternal TDF during pregnancy or during breastfeeding will be enrolled in this substudy.

This substudy will look at two groups of participants:

• An antepartum exposure group to look at the effects of TDF during pregnancy
• A postpartum exposure group to look at the effects of TDF during breastfeeding

All mother-infant pairs in the substudy will be followed for 74 weeks after delivery. During this time, the women and their infants will have medical checkups and tests. The tests will include tests of blood, urine, cord blood, and breast milk. Some of the women and infants will have a special x-ray called a dual energy e-ray absorptiometry (DXA) scan to measure bone strength. The timing of the tests—at enrollment, at delivery, at 6, 10, 26, or 74 weeks—will vary dependent on which part of this substudy women and infants are enrolled in. Those in charge of the substudy will try to schedule medical visits and tests at the same time as tests scheduled for the larger IMPAACT 1077 study.