Tenofovir Diphosphate Concentrations in Dried Blood Spots From Pregnant and Postpartum Adolescent and Young Women Receiving Daily Observed Pre-exposure Prophylaxis in Sub-Saharan Africa

Clin Infect Dis. 2021 Oct 5;73(7):e1893-e1900. doi: 10.1093/cid/ciaa1872.


Background: Intracellular tenofovir diphosphate (TFV-DP) concentration in dried blood spots (DBSs) is used to monitor cumulative pre-exposure prophylaxis (PrEP) adherence. We evaluated TFV-DP in DBSs following daily oral PrEP (emtricitabine 200 mg/tenofovir diphosphate 300 mg) among pregnant and postpartum adolescent girls and young women (AGYW).

Methods: Directly observed PrEP was administered for 12 weeks in a pregnancy (14-24 weeks' gestation, n = 20) and postpartum (6-12 weeks postpartum, n = 20) group of AGYW aged 16-24 years in sub-Saharan Africa. Weekly DBS TFV-DP was measured by validated liquid chromatography-tandem mass spectrometry assay. Week 12 TFV-DP distributions were compared between groups with Wilcoxon test. Population pharmacokinetic models were fit to estimate steady-state concentrations and create benchmarks for adherence categories. Baseline correlates of TFV-DP were evaluated.

Results: Median age was 20 (IQR, 19-22) years. Of 3360 doses, 3352 (>99%) were directly observed. TFV-DP median (IQR) half-life was 10 (7-12) days in pregnancy and 17 (14-21) days postpartum, with steady state achieved by 5 and 8 weeks, respectively. Observed median (IQR) steady-state TFV-DP was 965 fmol/punch (691-1166) in pregnancy versus 1406 fmol/punch (1053-1859) postpartum (P = .006). Modeled median steady-state TFV-DP was 881 fmol/punch (667-1105) in pregnancy versus 1438 fmol/punch (1178-1919) postpartum. In pooled analysis, baseline creatinine clearance was associated with observed TFV-DP concentrations.

Conclusions: TFV-DP in African AGYW was approximately one-third lower in pregnancy than postpartum. These Population-specific benchmarks can be used to guide PrEP adherence support in pregnant/postpartum African women.

Clinical trials registration: NCT03386578.

Keywords: PrEP in pregnancy; adolescence; intracellular TFV-DP.

Publication types

  • Clinical Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine / analogs & derivatives
  • Adolescent
  • Africa South of the Sahara
  • Anti-HIV Agents* / therapeutic use
  • Female
  • HIV Infections* / drug therapy
  • HIV Infections* / prevention & control
  • Humans
  • Medication Adherence
  • Organophosphates
  • Postpartum Period
  • Pre-Exposure Prophylaxis*
  • Pregnancy
  • Young Adult


  • Anti-HIV Agents
  • Organophosphates
  • tenofovir diphosphate
  • Adenine

Associated data

  • ClinicalTrials.gov/NCT03386578