First-trimester preeclampsia screening with biomarkers

Preeclampsia is a grave threat to maternal and infant health, with a growing prevalence in the developing world. But are current screening methods for the condition adequate?

First-trimester preeclampsia screening with biomarkers This is a summary of a longer, CPD accredited article available on www.medicalacademic.co.za

AN ALTERNATIVE APPROACH to screening, developed by The Fetal

Medicine Foundation (FMF), allows estimation of individual patient-specific risks of preeclampsia requiring delivery before a specified gestation, with the use of Bayes' theorem to combine the a-priori risk from maternal factors, derived by a multivariable logistic model, with the results of various combinations of biophysical and biochemical measurements. A recent multicentre study of 8775 singleton pregnancies confirmed the validity of this algorithm and reported detection rates of 100% (95% CI, 80–100%), 75% (95% CI,

T W E N T Y Y E A R S SADAG

MENTAL HEALTH FACT SHEET

LIFE-TIME PREVALENCE OF MENTAL DISORDERS IN SA

Compared with 14 other countries in the WMH Survey, South Africa is the:

2nd highest for substance abuse disorders (13.3%) 6th highest for anxiety disorders (15.8%) 7th highest for mood disorders (9.8%) MENTAL HEALTH IN SOUTH AFRICA • 3rd biggest contributor to the burden of disease • 7.7% reduction in mental hospital beds across all provinces • 11% of all non-natural death in SA is due to suicide • 16.5% of South Africans suffer from common mental health problems • 43.7% of people with HIV/AIDS have a mental health condition • 75% of clinic staff does not have a caring attitude • South Africa is in the bottom 4 countries providing mental health treatment PATIENT ADHERENCE AT A GOVERNMENT HOSPITAL Only 15.4% of patients take their meds as suggested by their dr 1 in 3 patients do not attend their dr’s appointments • Most common reasons are • Forgetfulness 28.6% • Lack of Support 24.2% • Adverse reactions 13% • Unavailability 11% +/- 6 mil South African suffers from PTSD +/- 8000 South Africans commit suicide each year 82.1% cannot afford private health care > 1% of health budget devoted to mental health

SOCIAL BURDEN FOR MENTAL HEALTH PATIENTS

Can’t take care of dependants Separated/ Divorced Lost friends Negative Family Relationships

17% 26% 47% 49%

SEEKING TREATMENT FOR MENTAL HEALTH

RESOURCES FOR MENTAL HEALTH Per 100,000 of the population there are:

9.72 Nurses 0.4 Social workers 0.27 Psychiatrists 0.32 Psychologists 2.8 beds for in-patients 1% beds for children

62–85%) and 43% (95% CI, 35–50%) for preeclampsia delivering < 32, < 37 and ≥ 37 weeks, respectively, at a 10% false positive rate. In the study, by O’Gorman et al, blood serum markers, PlFG and PAPP-A, in conjunction with maternal risk factors such as maternal characteristics, mean arterial blood pressure (MAP) and uterine artery pulsatility index (UAPI) achieved a detection rate of >90% at a false positive rate of 5%. This study clearly showed that the detection rate for high-risk patients increases when combining multiple parameters. The detection rate increases from 82% (when using maternal factors, MAP and UAPI) to 94% (when using maternal factors, MAP, UAPI, NT, PLGF and PAPP-A).

To study the use of the FMF algorithm in clinical practice, the ASPRE trial was designed to propose aspirin as a treatment for primary prevention of preeclampsia in all patients considered to be at high risk following first-trimester combined screening. This trial evaluated the effect of prophylactic low-dose aspirin administered in the first trimester of pregnancy on the incidence of delivery with preeclampsia before 37 weeks of gestation in patients at high risk. The secondary objectives were to study the effects of aspirin on the incidence of early preeclampsia, the incidence of intrauterine growth restriction, foetal death, perinatal death, admission to neonatal intensive care, a composite measure of neonatal morbidity and mortality and placental abruption. Patients were randomised to aspirin or a placebo.

The occurrence of preterm preeclampsia (< 37 weeks) was significantly reduced by aspirin (0.38; 95% CI 0.20–0.74; p = 0.004). Preterm preeclampsia occurred in 13 of 798 participants (1.6%) in the aspirin group, as compared with 35 of 822 (4.3%) in the placebo group. A dose of 150mg of aspirin per day was selected on the basis of previous evidence of a dose-dependent benefit. The trial demonstrated that aspirin reduces the risk of preterm pre-eclampsia, but not term pre-eclampsia only when initiated at ≤16 weeks of gestation.

CONCLUSION

The performance of first-trimester screening for preeclampsia by the FMF algorithm is far superior to the methods advocated by NICE and ACOG. Early identification of women at risk for pre-eclampsia testing serum biomarkers PAPP-A and PlGF allows for timely intervention with low dose aspirin (<16 weeks) to significantly reduce the incidence of preeclampsia. Early screening allows for closer monitoring of high-risk patients for optimal patient care.