Low placental growth factor levels mid-gestation predict small for gestational age in pregnant women with HIV.

Background: Placental growth factor (PlGF) and soluble Fms-like tyrosine kinase 1 (sFlt-1) are angiogenic factors essential for placental and fetal growth. Associations between these factors and birth outcomes among pregnant women with HIV are limited.

Methods: PlGF and sFlt-1 levels were quantified by ELISA in plasma samples collected between gestational weeks 24-29 from 114 women (46 with HIV, 68 without HIV). PlGF and sFlt-1:PlGF ratios were assessed using cut-offs used for prediction of preeclampsia (PlGF <12pg/mL, PlGF <100pg/mL, sFlt-1:PlGF >85), and compared by HIV status using χ2 testing. Logistic regression models were fit to assess associations of dichotomized PlGF and sFlt1:PlGF with preterm (<37weeks) and small for gestational age (SGA) birth (<10th percentile) in all participants and stratified by HIV status.

Results: Women with HIV were older than women without HIV. More women with HIV had low or very low PlGF levels (<100pg/mL: 30.4% vs 7.4%, p=0.001; <12pg/mL: 17.4% vs 1.5%, p=0.002) and sFlt-1:PlGF >85 (19.5% vs 2.9%, p=0.0036) than women without HIV. Among all pregnancies, low PlGF and high sFlt-1:PlGF ratio were significantly associated with SGA (odds ratio [95% confidence interval] for PlGF <12pg/mL: 10.3 [2.0-53], p=0.005; PlGF <100pg/mL: 5.9 [1.7-21], p=0.006; sFlt-1:PlGF >85: 10.6 [2.5-46], p=0.002), but not preterm birth. Associations remained significant after adjusting for maternal age, BMI, and elevated blood pressure. Stratification by maternal HIV status showed this association was limited to the women with HIV.

Conclusions: Low PlGF levels may be a good predictive biomarker of SGA specifically for pregnant women with HIV.