The authors have the following interests to declare: Abbott Laboratories provides Lopinavir/ritonavir for the parent trial. There are no patents, products in development or marketed products to declare. This does not alter the authors' adherence to all the PLoS ONE policies on sharing data and materials, as detailed online in the guide for authors.
Conceived and designed the experiments: SY EA EC TR DH DC. Performed the experiments: JM PN BO TC VA JA. Analyzed the data: SY KM AP EC TR DH DC. Wrote the manuscript: SY VA JA EC TR MK DH DC.
Maternal nutritional status is an important predictor of birth outcomes, yet little is known about the nutritional status of HIV-infected pregnant women treated with combination antiretroviral therapy (cART). We therefore examined the relationship between maternal BMI at study enrollment, gestational weight gain (GWG), and hemoglobin concentration (Hb) among 166 women initiating cART in rural Uganda.
Prospective cohort.
HIV-infected, ART-naïve pregnant women were enrolled between 12 and 28 weeks gestation and treated with a protease inhibitor or non-nucleoside reverse transcriptase inhibitor-based combination regimen. Nutritional status was assessed monthly. Neonatal anthropometry was examined at birth. Outcomes were evaluated using multivariate analysis.
Mean GWG was 0.17 kg/week, 14.6% of women experienced weight loss during pregnancy, and 44.9% were anemic. Adverse fetal outcomes included low birth weight (LBW) (19.6%), preterm delivery (17.7%), fetal death (3.9%), stunting (21.1%), small-for-gestational age (15.1%), and head-sparing growth restriction (26%). No infants were HIV-infected. Gaining <0.1 kg/week was associated with LBW, preterm delivery, and a composite adverse obstetric/fetal outcome. Maternal weight at 7 months gestation predicted LBW. For each g/dL higher mean Hb, the odds of small-for-gestational age decreased by 52%.
In our cohort of HIV-infected women initiating cART during pregnancy, grossly inadequate GWG was common. Infants whose mothers gained <0.1 kg/week were at increased risk for LBW, preterm delivery, and composite adverse birth outcomes. cART by itself may not be sufficient for decreasing the burden of adverse birth outcomes among HIV-infected women.
Clinicaltrials.gov
As the availability of combination antiretroviral therapy (cART) for HIV-infected pregnant women broadens and perinatal HIV transmission is reduced, there are increasing numbers of HIV-exposed, uninfected children worldwide
Given that nutritional status is a strong modifiable predictor of birth outcomes, we sought to characterize the baseline nutritional status of pregnant women initiating cART in rural Uganda and examine the associations between their nutritional status and adverse birth outcomes.
We analyzed nutritional data from an ongoing prospective clinical trial in Tororo, Uganda, evaluating malaria outcomes among women randomized to receive an HIV protease inhibitor or non-nucleoside reverse transcriptase inhibitor based cART regimen (NCT00993031,
Trained study staff collected baseline demographic data and general medical, HIV, and obstetric history. Close birth spacing was defined as <2 years between births (either live born or stillbirth) based on self-reported obstetric history. Socioeconomic status (SES) was assessed by performing principle component analysis of a series of questions about possession of a radio, telephone, television, motorcycle, or bicycle. We used the first two components of the principle component analysis which accounted for over 55% of the information contained in the 6 asset holding variables.
Maternal height was measured to the nearest 0.1 cm using a Seca 206 wall-mounted measuring tape and maternal weight was measured to the nearest 500 g using a Seca 876 mechanical scale. Gestational age was estimated based on last menstrual period (LMP) and fetal ultrasound at the screening visit. All women received a fetal ultrasound. Final pregnancy dating was based on ultrasound if the discrepancy between LMP and ultrasound was greater than 1 week in the 1st trimester, 2 weeks in the 2nd trimester or 3 weeks in the 3rd trimester
Women returned to the study clinic every four weeks until delivery for scheduled study visits as well as when they experienced adverse events or any health conditions requiring evaluation. At scheduled monthly visits, maternal weight was measured as described above. Laboratory evaluations were regularly conducted throughout pregnancy including Hb, HIV RNA PCR, and CD4/CD8 lymphocyte subsets. Clinical progression of HIV disease was categorized according to 2007 WHO criteria
If delivery took place in the hospital, trained study staff assessed infant anthropometry immediately after birth. Infant weight was measured to the nearest 10 g using a calibrated digital Seca 354 scale. Birth length was obtained using a locally made infant length board. Head circumference was measured to the nearest 0.1 cm using non-stretchable tape (Seca 212). If delivery occurred outside the study-affiliated hospital and infants were brought to the clinic, the anthropometric assessments were performed by study staff as described above. Only those infants who were measured within 12 hours of birth were included in this analysis. Infant HIV status at birth was determined by HIV-1 DNA PCR (Cobas Amplicor, Roche Diagnostics).
The following markers of maternal nutritional status were assessed: body mass index (BMI) at enrollment, baseline Hb, mean Hb during pregnancy, maternal weight at 24–28 weeks gestation
Infant outcomes included LBW, small for gestational age (SGA), stunting, wasting, underweight, preterm delivery, head-sparing growth restriction, and fetal death. LBW was defined as <2500 grams. SGA newborns were those with birth weight <10th percentile for their gestational age
We restricted the analysis to singleton pregnancies because of the well-established relationship between multiple births and LBW and preterm delivery
We calculated descriptive statistics and created scatterplots to assess distribution of the data and to inform regression modeling. Chi-square and Fisher’s exact tests were performed, as appropriate, to test for associations between categorical variables. Wilcoxon signed-rank tests were performed to compare the means of continuous characteristics by categorical variables. For all logistic and linear regression models, univariate analyses were first performed to assess relationships. Subsequently, multivariate logistic regression models were fit with dichotomous outcomes and clinically important predictors: birth spacing (<2 years) and CD4+ count at screening. Multivariate linear regression models were also built for continuous outcome variables. Birth spacing and CD4+ count were included in all models because of their clinical significance, as were any other predictors meeting the p≤0.2 threshold in univariate analysis. Multivariate model inputs were evaluated for significant multi-collinearity and where highly correlated, the variable with strongest association was retained. Model fit was assessed between model versions using differences in the −2 log likelihood and the difference in degrees of freedom between models relative to the Chi-square distribution. All analyses were conducted using SAS version 9.2 (Cary, North Carolina).
There were 232 women enrolled in the randomized clinical trial between December 15, 2009 and May 24, 2011. Of these, 166 delivered by May 24, 2011. Of these, 158 (95.2%) were singleton birth and were included in the analysis. Of the 158 births, 13.9% occurred outside the hospital. Birthweight was obtained within 12 hours of birth for 153 (96.8%) of the 158 women with singleton births.
The median age of participants at baseline was 29 years, and they were enrolled at a mean gestational age of 21.6 weeks (
Age, Median (IQR) | 29 (26, 34) |
Gestational age, Mean (SE) | 21.6 (0.3) |
Weight in kg, Median (IQR) (n = 157) | 57 (52, 62) |
Height in cm, Median (IQR) (n = 156) | 162 (158, 166) |
BMI, Mean (SE) (n = 155) | 21.8 (0.2) |
BMI (n = 155) | |
First tertile (<20.43) | 50 (32.3%) |
Second tertile (20.43–22.59) | 55 (35.5%) |
Third tertile (>22.59) | 50 (32.3%) |
Gravidity, Mean (SE) | 4.8 (0.2) |
Parity, Mean (SE) (n = 157) | 3.4 (0.2) |
Primigravid [n (%)] | 10 (6.3%) |
Number of living children, Mean (SE) | 2.9 (0.14) |
History of preterm delivery | 8 (5.1%) |
Years since last term birth, Mean (SE)(n = 145) | 4.1 (0.2) |
Education | |
Less than primary | 130 (82.3%) |
Primary or more | 28 (17.7%) |
Bednet at home(n = 157) | 85 (54.1%) |
HIV diagnosis during index pregnancy | 52 (32.9%) |
WHO Stage 1 | 145 (91.8%) |
WHO Stage 2 | 12 (7.6%) |
WHO Stage 3 | 1 (0.6%) |
CD4 cell count (n = 157) | |
<200 | 22 (14%) |
200–350 | 57 (36.3%) |
>350 | 78 (49.7%) |
Log(10) Viral Load, Mean (SE) (n = 154) | 4.08 (0.1) |
Hb, Mean (SE) | 11.05 (0.1) |
Anemia, Hb <11 | 71 (44.9%) |
Data are from entire sample (n = 158) unless otherwise noted.
All data are represented as n (%) unless otherwise noted.
IQR: Interquartile range.
SE: standard error.
BMI: Body mass index (kg/m2).
The median weekly GWG during study participation was 0.17 kg (interquartile range [IQR]: 0.06, 0.3). Data on median weekly GWG were unavailable for two participants who were not weighed within two weeks of delivery. Twenty-three women (14.6%) lost weight during pregnancy. The median total GWG during study participation was 3 kg (IQR: 1, 5). In addition, the median maternal weight at 7 months gestation was 58 kg (IQR: 52, 63) and the median BMI at 7 months gestation was 22 (IQR: 20.5, 24.1). Adjusting for birth spacing, baseline CD4 count, baseline weight, mean Hb during pregnancy, and Grade 3 or 4 adverse events, there were no significant predictors of gestational weight gain. (Univariate relationships and the full linear regression model can be found in
There were no infants infected with HIV at birth. The prevalence of LBW was 19.6%, preterm delivery 17.7%, and fetal death 3.9% (
Male sex (n = 155) | 83(53.6%) |
Overall low birth weight (n = 153) | 30 (19.6%) |
Overall preterm delivery | 28 (17.7%) |
Full term, normal birth weight (n = 152) | 111 (73.0%) |
Full term, low birth weight (n = 152) | 13 (8.6%) |
Preterm, normal birth weight (n = 152) | 11 (6.6%) |
Preterm, low birth weight (n = 152) | 12 (7.9%) |
Miscarriage (12–20 weeks) (n = 152) | 1 (0.6%) |
Stillbirth (>20 weeks) (n = 152) | 5 (3.3%) |
Composite adverse obstetric/fetal outcome | 64 (40.5%) |
Live born infants only (n = 152) |
|
Stunting (LAZ |
30 (21.1%) |
Small for gestational age (<10th percentile) | 23 (15.1%) |
Underweight (WAZ |
23 (15.1%) |
Wasting (WLZ |
11 (8.6%) |
Small head circumference (HCZ |
10 (6.7%) |
Head-sparing growth restriction (n = 150) | 39 (26.0%) |
All data are represented as n (%).
LAZ: length-for-age Z-score.
WAZ: weight-for-age Z-score.
WLZ: weight-for-length Z-score.
HCZ: head circumference Z-score.
In multivariate analysis adjusting for birth spacing (<2 years) and baseline CD4 count, each kg increase in maternal weight at enrollment was associated with a 30% decreased odds of LBW (aOR 0.70, 95% CI 0.52–0.95, p = 0.022, cf.
Adjusting for birth spacing (<2 years), baseline CD4 count, and any GWG, each g/dL increase in mean maternal Hb between enrollment and final measurement was associated with a 52% decreased odds of SGA (aOR 0.48, 95% CI 0.29–0.80, p = 0.004, cf.
After adjusting for birth spacing (<2 years) and baseline CD4 count, risk factors for neonatal stunting included male infant sex (aOR 6.02, 95% CI 1.64–22.06, p = 0.007), gestational age at delivery (aOR 0.51, 95%CI 0.37–0.71, p<0.001) and clinical malaria diagnosed during pregnancy (aOR 0.18, 95% CI 0.03–0.97, p = 0.047, cf.
There were no statistically significant predictors of head-sparing growth restriction in multivariate analysis adjusting for birth spacing, baseline CD4 count and mean maternal Hb during the study, cf.
Adjusting for birth spacing, baseline CD4 count and history of preterm delivery, GWG <0.1 kg per week was associated with a 4-fold increased odds of preterm delivery (aOR 3.46, 95% CI 1.18–10.15, p = 0.024, cf.
Lastly, predictors of the composite dichotomous adverse birth outcome included GWG <0.1 kg per week, higher SES status, and birth from June to October (the rainy season), adjusting for CD4 count and birth spacing (
Univariate Analysis | Final Multivariate Model | ||||||
N | Outcome (%) | OR | P | aOR |
95% CI | P | |
Birth spacing <2 years | 158 | 77 (44.4%) | 1.19 | 0.80 | 0.89 | 0.20–3.92 | 0.88 |
Baseline CD4 count (continuous) | 157 | 64 (40.8%) | 1 | 0.95 | 1 | 0.99–1.00 | 0.84 |
Maternal weight at 7 months gestation |
155 | 62 (40%) | 0.97 | 0.15 | 0.95 | 0.91–1.00 | 0.07 |
Weekly weight gain | |||||||
<0.1 kg/week | 54 | 28 (52%) | 2.12 | 0.03 | 2.85 | 1.32–6.15 | <0.01 |
0.1 kg/week or greater | 101 | 34 (33.7%) | – | 1 | |||
Higher SES |
148 | 30 (47%) | 1.67 | 0.13 | 2.61 | 1.20–5.67 | 0.02 |
Season of birth | |||||||
June to October | 56 | 16 (28.6%) | 0.45 | 0.03 | 0.33 | 0.15–0.74 | <0.01 |
November to May | 102 | 48 (47.1%) | 1 | – | 1 |
Composite adverse obstetric/fetal outcome includes any of the following: low birth weight, SGA, stunting, wasting, underweight, preterm delivery, and fetal death.
Adjusted odds ratio using multivariate logistic regression, adjusting for all variables listed in table.
Per kg increment in maternal weight at 7 months gestation.
Indicator variable for household being in the upper quartile of either the first or second component of the SES principal component analysis based on possession of a radio, telephone, television, motorcycle, bicycle or none of the above.
OR: Odds Ratio.
P: p-value.
aOR: Adjusted Odds Ratio.
95% CI: Confidence Interval.
Combination antiretroviral therapy is being delivered to increasing numbers of rural HIV-infected pregnant women in developing countries
In our cohort of HIV-infected pregnant women in rural Uganda initiating cART, TS and prenatal care, we found evidence of significant nutritional deficiencies. These women had low BMIs upon study entry and well into their pregnancy, despite having relatively preserved CD4 cell counts. Their mean weight gain of 0.17 kg/week was far below the 0.5 kg/week recommended by the Institute of Medicine for underweight women in industrialized countries in the second and third trimester
Interestingly, HIV severity, measured as baseline CD4 count, viral load, or WHO stage, was not predictive of adverse birth outcomes. This could have been due to our sample size and the relatively small proportion of women with severe immune suppression. Indeed, 50% of our cohort had baseline CD4 counts above 350 and the majority of the women (91.8%) were WHO stage 1.
Maternal nutritional predictors of preterm delivery and growth restriction have primarily been evaluated among HIV-infected women not receiving cART. The Pregnancy and HIV Study Group of 177 ARV-naïve women in Rwanda found that each kg increment in final weight before delivery was associated with a 6% decreased odds of LBW
Very few studies have evaluated nutritional predictors of pregnancy outcomes among HIV-infected women on cART. Ekouevi and colleagues studied 151 pregnant women receiving cART as part of the ANRS Ditrame Plus and the MTCT-Plus Projects in Cote d’Ivoire
It is reasonable to postulate that pregnant women treated with cART would have improved nutritional status compared to those without access to cART. Women receiving effective cART should experience less HIV morbidity, including diarrhea and wasting, which should outweigh the toxicity of the antiretroviral agents. However, our study and the two others examining nutritional markers among pregnant women receiving cART can neither support nor refute this assumption because all women received cART, and it would be unethical to randomize to non-cART treatment regimens. Furthermore, even if cART does improve nutritional status, we demonstrate in this cohort that there remain significant nutritional deficiencies and that these are associated with poor birth outcomes.
Mechanisms to explain these poor outcomes are likely numerous and not yet fully understood. For example, head-sparing, or asymmetric, growth restriction is thought to be due to preferential blood flow to the brain in the setting of placental insufficiency
Much work is needed to determine factors that contribute to low GWG and weight loss among HIV-infected pregnant women, including the impact of initiating HAART during pregnancy versus use of HAART prior to conception. It is also necessary to develop strategies to identify those women at greatest risk for poor birth outcomes. Pre-pregnancy BMI has consistently been associated with adverse birth outcomes. However, because most women do not know their pre-pregnancy weight and do not have regular access to preconception care, this indicator is not clinically useful. In order to identify another relevant maternal anthropometric predictor of adverse fetal outcomes, Kelly and colleagues conducted a meta-analysis of 25 studies including over 111,000 births worldwide
Preterm delivery, LBW, neonatal stunting, SGA, and wasting are strong predictors of infants’ future health trajectories
There are several limitations to our study. Small sample size may have impaired our ability to find statistically significant predictors of head-sparing fetal growth restriction and other poor outcomes. Our findings may not be generalizable to other cohorts of HIV-infected pregnant women receiving cART (e.g.
In conclusion, initiating cART during pregnancy among HIV–infected women in rural Uganda successfully prevented HIV transmission to their infants but did not prevent poor nutritional status during pregnancy that independently predicted poor birth outcomes. More attention is needed to characterize the scope and causes of nutritional deficiencies among this population and to design interventions that improve both the health of HIV-infected mothers and optimize the health and development of their offspring.
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The authors would like to sincerely thank the women who have participated in the PROMOTE-Pregnant Women and Infants trial. We would also like to acknowledge the dedicated PROMOTE study team, members of the Makerere University-University of California San Francisco Research Collaboration, and the midwives at Tororo District Hospital.