Birth Weight and Preterm Delivery Outcomes of Perinatally vs Nonperinatally Human Immunodeficiency Virus-Infected Pregnant Women in the United States: Results From the PHACS SMARTT Study and IMPAACT P1025 Protocol.

BACKGROUND: Pregnancy outcomes of perinatally human immunodeficiency virus-infected women (PHIV) are poorly defined. METHODS: We compared preterm delivery and birth weight (BW) outcomes (low BW [LBW], <2500 g), small-for-gestational-age [SGA], and BW z scores [BWZ]) in HIV-exposed uninfected infants of PHIV vs nonperinatally HIV-infected (NPHIV) pregnant women in the Pediatric HIV/AIDS Cohort Study Surveillance Monitoring of ART Toxicities or International Maternal Pediatric Adolescent AIDS Clinical Trials P1025 studies. Mixed effects models and log binomial models were used to assess the association of maternal PHIV status with infant outcomes. Age-stratified analyses were performed. RESULTS: From 1998 to 2013, 2270 HIV-infected pregnant women delivered 2692 newborns (270 born to PHIV and 2422 to NPHIV women). PHIV women were younger, (mean age 21 vs 25 years, P < .01) and more likely to have a pregnancy CD4 count <200 cells/mm3 (19% vs 11%, P = .01). No associations between maternal PHIV status and preterm delivery, SGA, or LBW were observed. After adjustment, BWZ was 0.12 lower in infants of PHIV vs NPHIV women (adjusted mean, -0.45 vs -0.33; P = .04). Among women aged 23-30 years (n = 1770), maternal PHIV was associated with LBW (aRR = 1.74; 95% confidence interval, 1.18, 2.58; P < .01). CONCLUSION: The overall lack of association between maternal PHIV status and preterm delivery or infant BW outcomes is reassuring. The higher rates of LBW observed in PHIV women aged 23-30 years warrants further mechanism-based investigations as this is a rapidly growing and aging population worldwide. CLINICAL TRIALS REGISTRATION: PHACS SMARTT study, NCT01310023. CLINICAL TRIALS REGISTRATION: IMPAACT 1025, NCT00028145.

Factors associated with lack of viral suppression at delivery among highly active antiretroviral therapy-naive women with HIV: a cohort study.

BACKGROUND: A high delivery maternal plasma HIV-1 RNA level (viral load [VL]) is a risk factor for mother-to-child transmission and poor maternal health. OBJECTIVE: To identify factors associated with detectable VL at delivery despite initiation of highly active antiretroviral therapy (HAART) during pregnancy. DESIGN: Multicenter observational study. (ClinicalTrial.gov: NCT00028145). SETTING: 67 U.S. AIDS clinical research sites. PATIENTS: Pregnant women with HIV who initiated HAART during pregnancy. MEASUREMENTS: Descriptive summaries and associations among sociodemographic, HIV disease, and treatment characteristics; pregnancy-related risk factors; and detectable VL (>400 copies/mL) at delivery. RESULTS: Between 2002 and 2011, 671 women met inclusion criteria and 13.1% had detectable VL at delivery. Factors associated with detectable VL included multiparity (16.4% vs. 8.0% nulliparity; P = 0.002), black ethnicity (17.6% vs. 6.6% Hispanic and 6.6% white; P < 0.001), 11th grade education or less (17.6% vs. 12.1% had a high school diploma; P = 0.013), initiation of HAART in the third trimester (23.9% vs. 12.3% and 8.6% in the second and trimesters, respectively; P = 0.003), having an HIV diagnosis before the current pregnancy (16.1% vs. 11.0% during the current pregnancy; P = 0.051), and having the first prenatal visit in the third trimester (33.3% vs. 14.3% and 10.5% in the second and third trimesters, respectively; P = 0.002). Women who had treatment interruptions or reported poor medication adherence were more likely to have detectable VL at delivery. LIMITATION: Data on many covariates were incomplete because women entered the study at varying times during pregnancy. CONCLUSION: A total of 13.1% of women who initiated HAART during pregnancy had detectable VL at delivery. The timing of HAART initiation and prenatal care, along with medication adherence during pregnancy, were associated with detectable VL at delivery. Social factors, including ethnicity and education, may help identify women who could benefit from focused efforts to promote early HAART initiation and adherence. PRIMARY FUNDING SOURCE: U.S. Department of Health and Human Services.

Pharmacokinetics and safety of single-dose tenofovir disoproxil fumarate and emtricitabine in HIV-1-infected pregnant women and their infants.

Tenofovir (TFV) is effective in preventing simian immunodeficiency virus (SIV) transmission in a macaque model, is available as the oral agent tenofovir disoproxil fumarate (TDF), and may be useful in the prevention of mother-to-child transmission of human immunodeficiency virus (HIV). We conducted a trial of TDF and TDF-emtricitabine (FTC) in HIV-infected pregnant women and their infants. Women received a single dose of either 600 mg TDF, 900 mg TDF, or 900 mg TDF-600 mg FTC at labor onset or prior to a cesarean section. Infants received no drug or a single dose of TDF at 4 mg/kg of body weight or of TDF at 4 mg/kg plus FTC at 3 mg/kg as soon as possible after birth. All regimens were safe and well tolerated. Maternal areas under the serum concentration-time curve (AUC) and concentrations at the end of sampling after 24 h (C(24)) were similar between the two doses of TDF; the maximum concentrations of the drugs in serum (C(max)) and cord blood concentrations were higher in women delivering via cesarean section than in those who delivered vaginally (P = 0.04 and 0.046, respectively). The median ratio of the TFV concentration in cord blood to that in the maternal plasma at delivery was 0.73 (range, 0.26 to 1.95). Without TDF administration, infants had a median TFV concentration of 12 ng/ml 12 h after birth. Following administration of a single dose of TDF at 4 mg/kg, infant TFV concentrations fell below the targeted level, 50 ng/ml, by 24 h postdose. In HIV-infected pregnant women and their infants, 600 mg of TDF is acceptable as a single dose during labor. Low concentrations at birth support infant dosing as soon after birth as possible. Rapidly decreasing TFV levels in infants suggest that multiple or higher doses of TDF will be necessary to maintain concentrations that are effective for viral suppression.

Postpartum viral load rebound in HIV-1-infected women treated with highly active antiretroviral therapy: AIDS Clinical Trials Group Protocol A5150.

BACKGROUND: Pregnancy may lead to increases in HIV-1 RNA levels postpartum. The AIDS Clinical Trials Group (ACTG) A5150 study was designed to characterize the incidence of viral load rebound during the immediate 24 weeks postpartum and explore factors associated with viral load rebound. METHODS: We enrolled pregnant women in the United States who were ≥13 years of age, between 22 to 30 weeks gestation, and who planned to be on stable highly active antiretroviral therapy (HAART) for ≥8 weeks predelivery and to continue this therapy after delivery for the duration of the study. Choice of antiretrovirals (ARVs) was determined by the primary HIV provider. Viral load rebound was defined as an increase of ≥0.7 log10 (5-fold) from the average of the weeks 34 and 36 gestation viral loads to week 24 postpartum or an absolute increase to ≯500 copies/mL for those with viral load <50 copies/mL. RESULTS: Eighty-four women enrolled for postpartum follow-up. Sixty-three had follow-up and viral load obtained through week 24 postpartum. Overall, 18/63 (28.6%; 95% confidence interval [CI], 17.9-41.4) met criteria for viral load rebound. Nineteen of the 63 women made changes or discontinued their ARV regimen prior to week 24 postpartum. For those who remained on stable ARVs, rebound occurred in 8/44 (18.2%; 95% CI, 8.2-32.7) compared with 10/19 (52.6%; 95% CI, 28.9-75.5) who did not remain on a stable ARV regimen. CONCLUSIONS: In the early postpartum period, HIV-1-infected women commonly have increases in viral load. Unplanned changes in ARV regimens and discontinuations of treatment are frequent.

Prenatal protease inhibitor use and risk of preterm birth among HIV-infected women initiating antiretroviral drugs during pregnancy.

BACKGROUND: Conflicting results have been reported among studies of protease inhibitor (PI) use during pregnancy and preterm birth. Uncontrolled confounding by indication may explain some of the differences among studies. METHODS: In total, 777 human immunodeficiency virus (HIV)-infected pregnant women in a prospective cohort who were not receiving antiretroviral (ARV) treatment at conception were studied. Births <37 weeks gestation were reviewed, and deliveries due to spontaneous labor and/or rupture of membranes were identified. Risk of preterm birth and low birth weight (<2500 g) were evaluated by using multivariable logistic regression. RESULTS: Of the study population, 558 (72%) received combination ARV with PI during pregnancy, and a total of 130 preterm births were observed. In adjusted analyses, combination ARV with PI was not significantly associated with spontaneous preterm birth, compared to ARV without PI (odds ratio [OR], 1.22; 95% confidence interval [CI], 0.70-2.12). Sensitivity analyses that included women who received ARV prior to pregnancy also did not identify a significant association (OR, 1.34; 95% CI, 0.84-2.16). Low birth weight results were similar. CONCLUSIONS: No evidence of an association between use of combination ARV with PI during pregnancy and preterm birth was found. Our study supports current guidelines that promote consideration of combination ARV for all HIV-infected pregnant women.

Pregnancy outcomes in young women with perinatally acquired human immunodeficiency virus-1.

OBJECTIVE: The objective of the study was to review pregnancy and neonatal outcomes among perinatally infected pregnant patients at our institution. STUDY DESIGN: A retrospective review of maternal and neonatal records for all 10 perinatally infected adolescents between 1997 and 2007 was performed. Demographics, CD4 and viral load, antiretroviral treatment, medical comorbidities, pregnancy outcomes, and neonatal human immunodeficiency virus (HIV) status were abstracted. RESULTS: The median age at first pregnancy was 18.5 years and 70% were African American. The most common comorbidities were hematologic abnormalities (70%) and cervical dysplasia/sexually transmitted infections (STIs) (80%). Initial median CD4 and viral load were 317 cells/mm(3) and 8780 copies/mL, respectively. The median gestational age at delivery was 38 weeks. The most common obstetrical complications were preeclampsia (23%) and premature rupture of membranes/preterm delivery (31%). The cesarean delivery (CD) rate was 62%, with HIV as the indication in 75%. All infants were born alive; 1 was HIV infected. CONCLUSION: Despite high rates of STIs, CD, preterm delivery, and hypertensive disorders, perinatal outcomes were favorable.

Lipids and lactate in human immunodeficiency virus-1 infected pregnancies with or without protease inhibitor-based therapy.

OBJECTIVE: To evaluate the effect of protease inhibitors on lipid and lactate levels and gastrointestinal symptoms in pregnancy. METHODS: Acquired Immunodeficiency Syndrome (AIDS) Clinical Trials Group (ACTG) A5084 was an observational cohort study of human immunodeficiency virus (HIV)-infected pregnant women. Women recruited between 20 and 34 weeks of gestation were required to be on a stable, highly active antiretroviral therapy (HAART) regimen, stratified by protease inhibitor compared with no protease inhibitor regimens. Interval history was assessed, and lipid and lactate levels were drawn every 8 weeks during pregnancy and 12 weeks postpartum, with levels closest to delivery and postpartum used for analysis. Statistical comparisons used Kruskal-Wallis and Fisher exact tests. RESULTS: One-hundred fifty-eight women were evaluated. Total cholesterol levels (median 230 mg/dL, interquartile range [197, 259], compared with 212 [179, 246] mg/dL, P=.042) and triglycerides (median 224 mg/dL, interquartile range [187, 288], compared with 185 [142, 230] mg/dL, P<.001] were elevated in the protease inhibitor group during pregnancy and remained higher in this group after delivery (total cholesterol 185 [163, 224] mg/dl compared with 171 [140, 190] mg/dL, P<.004; triglycerides 122 [87, 175] mg/dL compared with 89 [66, 150] mg/dL, P=.02). No difference was seen in lactate levels or rates of gastrointestinal symptoms between groups. Obstetric outcomes were similar between the two groups. A higher number of low birth weight infants were born to women in the highest twentieth percentile of triglycerides compared with the lowest across medication groups. CONCLUSION: Cholesterol and triglycerides were higher in protease inhibitor-treated women in pregnancy. Lactate and gastrointestinal symptoms were not different. A higher number of low birth weight infants were noted in women with high triglycerides, but other elevated lipid levels did not affect pregnancy outcomes. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00017797 LEVEL OF EVIDENCE: II.

Preterm premature rupture of membranes in pregnancies complicated by human immunodeficiency virus infection: a single center's five-year experience.

OBJECTIVE: The objective of this study was to describe one center's five-year experience of the management of human immunodeficiency virus (HIV) positive gravidas with preterm premature rupture of the membranes (PPROM) not in labor at

The impact of sex and contraceptive therapy on the plasma and intracellular pharmacokinetics of zidovudine.

OBJECTIVES: Zidovudine remains part of combination antiretroviral therapy. Pharmacological studies rely on quantitation of active triphosphates in peripheral blood mononuclear cells. This study evaluated the impact of female sex and contraceptive therapy on zidovudine plasma and intracellular pharmacokinetics and the impact of contraceptive therapy on HIV viral load. METHODS: Serial plasma and intracellular zidovudine pharmacokinetics following oral and intravenous dosing were determined in 18 men and 20 women treated with zidovudine. Women could repeat pharmacokinetics assessment following 2 months oral or injectable contraceptive therapy. Zidovudine plasma and intracellular mono-, di- and triphosphate concentrations were determined by liquid chromatography tandem mass spectrometry. Plasma and cervical viral loads were determined preceding and following 2 months of contraceptive therapy in women. RESULTS: Men exhibited higher area under the concentration versus time curve for intracellular zidovudine and zidovudine-monophosphate following oral and intravenous dosing and higher zidovudine triphosphate following oral dosing. There was no difference between men and women in plasma zidovudine parameters. Furthermore, contraceptive therapy had no effect on zidovudine plasma or intracellular pharmacokinetics or on plasma or cervical HIV-1 RNA levels. CONCLUSIONS: Using an optimized pharmacokinetic design, this study indicated men exhibit significantly higher zidovudine-monophosphate and zidovudine-triphosphate exposure following zidovudine oral administration, having implications for drug toxicity and overall tolerance of zidovudine therapy. The lack of an effect of contraceptive therapy on zidovudine pharmacokinetics is surprising in light of previous pharmacokinetic studies for drugs eliminated primarily through glucuronidation. Contraceptive therapy had no effect on plasma or cervical viral load, results consistent with previous findings.

Assisted reproductive technology for men and women infected with human immunodeficiency virus type 1.

In 2001, the World Health Organization reported 4.3 million new human immunodeficiency virus (HIV) infections in adults globally, 41% of which were in women. During the year 2000, 27% of newly diagnosed HIV infections in the United States occurred in women. In developed countries, the perception of HIV infection has changed from an acute, lethal infection to a chronic illness; the introduction of highly active antiretroviral therapy has decreased morbidity and mortality, and new drug therapies have dramatically decreased perinatal transmission. In view of these advances, some HIV-infected individuals are considering reproduction. Following the lead of organizations in other developed countries, the American College of Obstetricians and Gynecologists has recently endorsed the use of reproductive technology in HIV-infected patients. Which patients should be offered assisted reproduction and what the optimal methods are of decreasing heterosexual and perinatal HIV transmission must be determined.

Human immunodeficiency virus infection in advanced maternal age gravidas.

Our study compares perinatal outcomes among HIV(+) versus HIV(-) advanced maternal aged (AMA) women. A retrospective cohort study of AMA deliveries from 2000 to 2009 was performed. HIV(+) (group A) women were compared to temporally matched HIV(-) (group B) women. Demographics, medical comorbidities, HIV treatment, and delivery data were collected. SAS was used for data analysis with p<0.05 considered significant. Seventy-one patients per study group were reviewed; for group A, the mean CD4 count near delivery was 507±363; 75% (34/45) had viral load ≤400 in the third trimester and 58% were on a protease inhibitor regimen. HIV(+) women had significantly higher preterm delivery (PTD) <37 weeks (A: 40.85%, B: 16.90%, p=0.0016). Logistic regression performed revealed that the odds of PTD was 2.83 (CI 1.22-6.54) for HIV(+) and 4.02 (CI 1.27-12.72) for drug use independent of other factors. The pathophysiology of PTD among HIV(+) AMA women warrants prospective examination to better define the causal relationship.

Mode of delivery and infant respiratory morbidity among infants born to HIV-1-infected women.

OBJECTIVE: To estimate risk of infant respiratory morbidity associated with cesarean delivery before labor and ruptured membranes among HIV-1-infected women. METHODS: In a prospective cohort study of HIV-1-infected women and their infants, mode of delivery was determined by clinicians at the participating sites. For this analysis, "elective cesarean delivery" was defined as any cesarean delivery, regardless of gestational age, without labor and with duration of ruptured membranes of less than 5 minutes. Nonelective cesarean deliveries were those performed after the onset of labor, rupture of membranes, or both. Vaginal delivery included normal spontaneous and instrument deliveries. Associations between mode of delivery and infant respiratory morbidity were assessed using chi or Fisher's exact test. Adjusted odds of respiratory distress syndrome by delivery mode were assessed using multivariable logistic regression. RESULTS: Among 1,194 mother-infant pairs, there were significant differences according to mode of delivery in median gestational age (weeks) at delivery (vaginal, n=566, median=38.8; nonelective cesarean, n=216, median=38.0; and elective cesarean, n=412, median 38.1; P<.001) and incidence of respiratory distress syndrome (vaginal, n=9, 1.6%, reference; nonelective cesarean, n=16, 7.4%; elective cesarean, n=18; 4.4%; (P<.001). In analyses adjusted for gestational age and birth weight, mode of delivery was not statistically significantly associated with infant respiratory distress syndrome (P=.10), although a trend toward an increased risk of respiratory distress syndrome among infants delivered by cesarean was suggested (nonelective cesarean adjusted odds ratio [OR] 2.32, 95% confidence interval [CI] 0.95-5.67; elective cesarean OR 2.56, 95% CI 1.01-6.48). CONCLUSION: Respiratory distress syndrome rates associated with elective cesarean delivery among HIV-1-infected women are low, comparable with published rates among uninfected women. There is minimal neonatal respiratory morbidity risk in near-term infants born by elective cesarean delivery to HIV-1-infected women. LEVEL OF EVIDENCE: II.

Prior illicit drug use and missed prenatal vitamins predict nonadherence to antiretroviral therapy in pregnancy: adherence analysis A5084.

Adherence to antiretroviral therapy (ART) in pregnancy is crucial to optimize its efficacy and minimize mother-to-child transmission. Our objective was to examine adherence patterns to ART and health behaviors during and after pregnancy among HIV-positive women enrolled in A5084, a prospective, observational, multisite study. Between 2002-2005, HIV-infected women between 20 and 34 weeks'gestation completed at least 1 self-reported adherence questionnaire antepartum (AP), and were followed through 12 weeks' postpartum (PP). Questionnaires also addressed tobacco, alcohol, and illicit drugs use. Adherence was defined as reporting not having missed any doses for more than 3 months. Exact McNemar's tests were used for paired binary data and exact logistic regression was used for predictors of nonadherence. We report on 149 women (55% black, 26% Hispanic, 32% less than 25 years, 9% with AIDS, 100% on ART). PP, 31 (21%) women stopped ART and 18 (12%) withdrew from the study. AP, 57% reported adherence to ART and PP, 45% (p = 0.03, n = 87). AP, 11% reported ongoing alcohol use and 23% tobacco use compared to 37% and 30% PP (p < 0.0001, n = 103; p = 0.07, n = 99, respectively). Although 39% ever used marijuana (n = 116) and 25% used illicit drugs (n = 107), few participants reported use during the study. In multivariate analyses, those who had ever used illicit drugs had 5.95 times higher odds (p = 0.002) and those who missed prenatal vitamins had 4.84 times higher odds (p = 0.001) of ART nonadherence. Women reporting a history of illicit drug use and/or having missed prenatal vitamins should be targeted for programs to enhance adherence to ART during pregnancy.

Adherence to antiretrovirals among US women during and after pregnancy.

BACKGROUND: Antiretrovirals (ARVs) are recommended for maternal health and to reduce HIV-1 mother-to-child transmission, but suboptimal adherence can counteract its benefits. OBJECTIVES: To describe antepartum and postpartum adherence to ARV regimens and factors associated with adherence. METHODS: We assessed adherence rates among subjects enrolled in Pediatric AIDS Clinical Trials Group Protocol 1,025 from August 2002 to July 2005 on tablet formulations with at least one self-report adherence assessment. Perfectly adherent subjects reported no missed doses 4 days before their study visit. Generalized estimating equations were used to compare antepartum with postpartum adherence rates and to identify factors associated with perfect adherence. RESULTS: Of 519 eligible subjects, 334/445 (75%) reported perfect adherence during pregnancy. This rate significantly decreased 6, 24, and 48 weeks postpartum [185/284 (65%), 76/118 (64%), and 42/64 (66%), respectively (P < 0.01)]. Pregnant subjects with perfect adherence had lower viral loads. The odds of perfect adherence were significantly higher for women who initiated ARVs during pregnancy (P < 0.01), did not have AIDS (P = 0.02), never missed prenatal vitamins (P < 0.01), never used marijuana (P = 0.05), or felt happy all or most of the time (P < 0.01). CONCLUSIONS: Perfect adherence to ARVs was better antepartum, but overall rates were low. Interventions to improve adherence during pregnancy are needed.

Clinical response and tolerability to and safety of saquinavir with low-dose ritonavir in human immunodeficiency virus type 1-infected mothers and their infants.

Saquinavir boosted with low-dose ritonavir given with zidovudine and lamivudine was well tolerated by pregnant women and their infants. All mothers had <400 human immunodeficiency virus type 1 RNA copies/ml at delivery. Two had elevated liver transaminases and amylase. Seven infant adverse events were possibly treatment related (anemia, neutropenia, and hyperbilirubinemia).

Effect of pregnancy and human immunodeficiency virus infection on intracellular interleukin-2 production patterns.

Human immunodeficiency virus type 1 (HIV-1) infection decreases the production of interleukin-2 (IL-2) from CD4+ and CD8+ T cells. Recombinant IL-2 (rIl-2) has been given to HIV-infected individuals to generate significant increases in CD4+ T-cell counts. There are limited data regarding the effects of pregnancy and HIV infection on IL-2 production in humans. To investigate the effects of human pregnancy, HIV infection, and HIV therapy on IL-2 production, we evaluated 61 women. Intracellular IL-2 production by CD4+ T cells from nonpregnant HIV-infected women was significantly lower than in that in uninfected women (45% +/- 8% versus 52% +/- 8%, P = 0.04). In contrast, there was no difference in levels of intracellular IL-2 production between HIV-infected and uninfected pregnant women. These observations suggest that pregnancy may down-regulate IL-2 production regardless of HIV infection status. Future studies should evaluate IL-2 production patterns in larger cohorts of women so that the physiological significance of IL-2 down-regulation in pregnancy can be further evaluated. This information is essential to assess the possible use of IL-2 supplementation therapy as a means of enhancing immune responses among HIV-infected pregnant women.

Telomere length in the newborn.

Telomere length is similar in different organs of the human fetus but variable among fetuses. During extrauterine life telomere length is highly variable among individuals and longer in women than men. In the present work we addressed the following questions: 1) Are there sex-related differences in telomere length at birth? 2) Is there synchrony (i.e. correlation in length) of telomeres in tissues within the newborn? 3) Is the variability in telomere length among newborns as large as that in adults? We studied normal male and female newborns who donated DNA samples from three sources: white blood cells, umbilical artery, and foreskin. Telomere length was measured by the mean length of the terminal restriction fragments (TRF). TRF length was not different between male and female newborns. It was highly synchronized among the DNA samples from white blood cells, umbilical artery and skin within individual donors but exhibited a high variability among donors. We conclude that there is no evidence for the effect of sex on telomere length at birth, suggesting that longer telomeres in women than men arise from a slower rate of telomeric attrition in women. The variability in telomere length among newborns and synchrony in telomere length within organs of the newborn are consistent with the concept that variations in telomere length among adults are in large part attributed to determinants (genetic and environmental) that start exerting their effect in utero.

Pharmacokinetics of saquinavir plus low-dose ritonavir in human immunodeficiency virus-infected pregnant women.

The physiologic changes that occur during pregnancy make it difficult to predict antiretroviral pharmacokinetics (PKs), but few data exist on the PKs of protease inhibitors in human immunodeficiency virus (HIV)-infected pregnant women. The objective of the present study was to determine the PKs of ritonavir (RTV)-enhanced saquinavir (SQV) in HIV-infected pregnant women by an area under the curve (AUC)-targeted approach. A phase I, formal PK evaluation was conducted with HIV-infected pregnant woman during gestation, during labor and delivery, and at 6 weeks postpartum. The SQV-RTV regimen was 800/100 mg twice a day (b.i.d.), and nucleoside analogs were administered concomitantly. The SQV exposure targeted was an AUC at 24 h of 10,000 ng. h/ml. Participants were evaluated for 12-h steady-state PKs at each time period. Thirteen subjects completed the PK evaluations during gestation, 7 completed the PK evaluations at labor and delivery, and 12 completed the PK evaluations postpartum. The mean baseline weight was 67.4 kg, and the median length of gestation was 23.3 weeks. All subjects achieved SQV exposures in excess of the target AUC. The SQV AUCs at 12 h (AUC(12)s) during gestation (29,373 +/- 17,524 ng. h/ml [mean +/- standard deviation]), during labor and delivery (26,189 +/- 22,138 ng. h/ml), and during the postpartum period (35,376 +/- 26,379 ng. h/ml) were not significantly different. The mean values of the PK parameters for RTV were lower during gestation than during the postpartum period: for AUC(12), 7,811 and 13,127 ng. h/ml, respectively; for trough concentrations, 376 and 632 ng/ml, respectively; and for maximum concentrations, 1,256 and 2,252 ng/ml, respectively (P