Maternal plasma soluble fms-like tyrosine kinase-1 and placental growth factor levels as biochemical markers of gestational hypertension for Malaysian mothers

The feasibility of soluble Fms-Like Tyrosine kinase-1 (sFLT-1) and Placental Growth Factor (PlGF) ratio biomarker in predicting preeclampsia and adverse pregnancy outcomes among medium to high risk mothers in Kuala Lumpur, Malaysia

Background

Preeclampsia significantly contributes to maternal and perinatal morbidity and mortality. It is imperative to identify women at risk of developing preeclampsia in the effort to prevent adverse pregnancy outcomes through early intervention. Soluble fms-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) level changes are noticeable several weeks before the onset of preeclampsia and its related complications. This study evaluated the feasibility of the sFlt-1/PlGF biomarker ratio in predicting preeclampsia and adverse pregnancy outcomes using a single cut-off point of >38.

Methods

This is a prospective cohort study conducted at a single tertiary centre, in an urban setting in Kuala Lumpur, Malaysia, between December 2019 and April 2021. A total of 140 medium to high risk mothers with singleton pregnancies were recruited at ≥20 weeks’ gestation. sFlt-1/PlGF ratio was measured and the participant monitored according to a research algorithm until delivery. The primary outcome measure was incidence of preeclampsia and the secondary outcome measure was incidence of other adverse pregnancy outcomes.

Results

The overall incidence of preeclampsia was 20.7% (29/140). The mean sFlt-1/PlGF ratio was significantly higher in preeclampsia (73.58 ± 93.49) compared to no preeclampsia (13.41 ± 21.63) (p = 0.002). The risk of preeclampsia (adjusted OR 28.996; 95% CI 7.920–106.164; p<0.001) and low Apgar score (adjusted OR 17.387; 95% CI 3.069–98.517; p = 0.028) were significantly higher among women with sFlt-1/PlGF ratio >38 compared with sFLT-1/PlGF ratio ≤38. The area under the receiver-operator characteristic curve (AUC) for a combined approach (maternal clinical characteristics and biomarker) was 86.9% (p<0.001, 95% CI 78.7–95.0) compared with AUC biomarker alone, which was 74.8% (p<0.001, 95% CI 63.3–86.3) in predicting preeclampsia. The test sensitivity(SEN) was 58.6%, specificity (SPEC) 91%,positive predictive value (PPV) 63% and negative predictive value (NPV) 89.3% for prediction of preeclampsia. For predicting a low Apgar score at 5 minutes, the SEN was 84.6%, SPEC 87.4%, PPV 40.7%, and NPV 98.2%; low birth weight with SEN 52.6%,SPEC 86.0%, PPV 37.0%, NPV 92.0%; premature delivery with SEN 48.5%, SPEC 89.5%, PPV 59.3%, NPV 84.7% and NICU admission with SEN 50.0%, SPEC 85.8%, PPV 37.0% and NPV 91.2%.

Conclusions

It is feasible to use single cut-off point of >38 ratio of the biomarkers sFlt-1/PlGF in combination with other parameters (maternal clinical characteristics) in predicting preeclampsia and adverse pregnancy outcomes among medium to high risk mothers without restricting outcome measurement period to 1 and 4 weeks in a single urban tertiary centre in Kuala Lumpur, Malaysia.

Predicting hypertensive disorders in pregnancy using multiple methods: Models with the placental growth factor parameter

BACKGROUND

Placental growth factor (PlGF), one of the biomarkers, has a certain predictive effect on hypertensive disorders in pregnancy (HDP).

OBJECTIVE

To study the HDP prediction effect of different methods for variable selection and modeling for models containing PlGF.

METHODS

For the model containing PlGF, the appropriate range of PlGF parameters needed to be selected. Step-logistic regression and lasso were used to compare the model effect of twice range selection. The PlGF model with good predictive effect and appropriate detecting gestational age was selected for the final prediction.

RESULTS

The effect of the model containing PlGF tested at 15-16 weeks was better than the PlGF value without comprehensive screening. The sensitivity of both methods was over 92%. By comprehensive comparison, the final model of lasso method in this study was more effective.

CONCLUSIONS

In this study, a variety of methods were used to screen models containing PlGF parameters. According to clinical needs and model effects, the optimal HDP prediction model with PlGF parameters in the second trimester of 15-26 weeks of pregnancy was finally selected.

Maternal Choline and Betaine Supplementation Modifies the Placental Response to Hyperglycemia in Mice and Human Trophoblasts

Gestational diabetes mellitus (GDM) is characterized by excessive placental fat and glucose transport, resulting in fetal overgrowth. Earlier we demonstrated that maternal choline supplementation normalizes fetal growth in GDM mice at mid-gestation. In this study, we further assess how choline and its oxidation product betaine influence determinants of placental nutrient transport in GDM mice and human trophoblasts. C57BL/6J mice were fed a high-fat (HF) diet 4 weeks prior to and during pregnancy to induce GDM or fed a control normal fat (NF) diet. The HF mice also received 25 mM choline, 85 mM betaine, or control drinking water. We observed that GDM mice had an expanded placental junctional zone with an increased area of glycogen cells, while the thickness of the placental labyrinth zone was decreased at E17.5 compared to NF control mice (p < 0.05). Choline and betaine supplementation alleviated these morphological changes in GDM placentas. In parallel, both choline and betaine supplementation significantly reduced glucose accretion (p < 0.05) in in vitro assays where the human choriocarcinoma BeWo cells were cultured in high (35.5 mM) or normal (5.5 mM) glucose conditions. Expression of angiogenic genes was minimally altered by choline or betaine supplementation in either model. In conclusion, both choline and betaine modified some but not all determinants of placental transport in response to hyperglycemia in mouse and in vitro human cell line models.

Comparison of placental growth factor and fetal flow Doppler ultrasonography to identify fetal adverse outcomes in women with hypertensive disorders of pregnancy: an observational study

BACKGROUND

Hypertensive disorders of pregnancy and intrauterine growth restriction (IUGR) are leading causes of maternal and perinatal morbidity and mortality. Failure to detect intrauterine growth restriction in women at high risk has been highlighted as a significant avoidable cause of serious fetal outcome. In this observational study we compare fetal flow using Doppler ultrasonography with a new test for placental growth factor (PlGF) to predict fetal adverse events.

METHODS

Eighty-nine women with hypertensive disorders of pregnancy (24 with chronic hypertension, 17 with gestational hypertension, 12 with HELLP syndrome, 19 with preeclampsia and 17 with superimposed preeclampsia) were enrolled. A single maternal blood sample to measure free PlGF (Alere Triage) taken before 35 weeks of pregnancy was compared to the last Doppler ultrasound measurement of fetal flow before delivery. PlGF was classified as normal (PlGF≥100 pg/ml), low (12<PlGF<100) or very low (PlGF≤12 pg/ml). A positive test for abnormal fetal flow was defined as either signs of centralisation of the fetal circulation or diastolic block or reverse flow in the umbilical artery or descending aorta; this was a criterion for delivery. Fetal outcomes were intrauterine growth restriction and birth before 37 weeks of pregnancy.

RESULTS

In total 61/89 women had a preterm birth and 22 infants had IUGR. Of those who delivered preterm, 20/20 women with abnormal fetal flow and 36/41 (87.8%) women with normal fetal flow had low or very low PlGF. Of those infants with IUGR, 22/22 had low or very low maternal PlGF and 10/22 had abnormal fetal flow.

CONCLUSIONS

PlGF may provide useful information before 35th gestational week to identify fetuses requiring urgent delivery, and those at risk of later adverse outcomes not identified by fetal flow Doppler ultrasonography.

Evaluation of a rapid and simple placental growth factor test in hypertensive disorders of pregnancy

The aim of this study was to investigate the diagnostic accuracy of the Triage placental growth factor (PlGF) assay, together with its prognostic efficiency in determining the need for preterm delivery in all forms of hypertensive disorders of pregnancy. A total of 130 pregnant women with a diagnosis of preeclampsia (PE: 23), HELLP syndrome (20), superimposed preeclampsia (SIPE: 17), chronic hypertension (CHT: 25), gestational hypertension (GHT: 18) and 27 normotensive pregnant controls were enrolled in this case-control study. A single blood sample was taken between 22 and 34 weeks of gestation, and the plasma was analyzed for PlGF using the Alere Triage PlGF assay. The PlGF levels found in all hypertensive disorder groups differed significantly from those observed in controls. There was a highly significant difference in PlGF concentrations between women with a pregnancy duration <35 weeks and controls. Using a gestational age-dependent threshold of 5% of normal, a positive PlGF test predicted delivery before 35 weeks in 93.7% of hypertensive women and delivery before 37 weeks in 90.5% of hypertensive women. A positive PlGF test identified the following proportions of hypertensive patients: 95.7% (PE), 95.0% (HELLP syndrome), 82.4% (SIPE), 60.0% (CHT) and 44.4% (GHT). A positive PlGF test was associated with a significantly shorter duration of pregnancy (hazard ratio of 3.43 adjusted for the gestational age at the time of sample collection and hypertension with proteinuria). In conclusion, PlGF concentrations are significantly lower in all hypertensive disorders. A positive test using the Triage PlGF assay at 22-34 weeks of gestation predicts delivery before 37 weeks in women with both proteinuric and non-proteinuric hypertensive disorders of pregnancy.

The sFlt-1/PlGF ratio in different types of hypertensive pregnancy disorders and its prognostic potential in preeclamptic patients

OBJECTIVE

The soluble fms-like tyrosine kinase (sFlt-1)/placental growth factor (PlGF) ratio is a reliable tool in the assessment of preeclampsia. We tested the hypothesis that the sFlt-1/PlGF ratio is able to identify women at risk for imminent delivery. We characterized the sFlt-1/PlGF ratio in different types of hypertensive pregnancy disorders.

STUDY DESIGN

We investigated 388 singleton pregnancies with normal pregnancy outcome, 164 with PE, 36 with gestational hypertension, and 42 with chronic hypertension. sFlt-1 and PlGF were measured in serum samples.

RESULTS

Patients with preeclampsia had a significantly increased sFlt-1/PlGF ratio as compared with controls and with patients with chronic and gestational hypertension in <34 weeks and ≥34 weeks (P < .001). Time to delivery was significantly reduced in women with preeclampsia in the highest quartile of the sFlt-1/PlGF ratio (P < .001).

CONCLUSION

The sFlt-1/PlGF ratio allows the identification of women at risk for imminent delivery and is a reliable tool to discriminate between different types of pregnancy-related hypertensive disorders.