Placental Alpha-Microglobulin-1 Test in Resource-Limited Settings: A Cost-Effectiveness Analysis

AACC Guidance Document on the Use of Point-of-Care Testing in Fertility and Reproduction

Background

The AACC Academy revised the reproductive testing section of the Laboratory Medicine Practice Guidelines: Evidence-Based Practice for Point-of-Care Testing (POCT) published in 2007.

Methods

A panel of Academy members with expertise in POCT and laboratory medicine was formed to develop guidance for the use of POCT in reproductive health, specifically ovulation, pregnancy, premature rupture of membranes (PROM), and high-risk deliveries. The committee was supplemented with clinicians having Emergency Medicine and Obstetrics/Gynecology training.

Results

Key recommendations include the following. First, urine luteinizing hormone (LH) tests are accurate and reliable predictors of ovulation. Studies have shown that the use of ovulation predicting kits may improve the likelihood of conception among healthy fertile women seeking pregnancy. Urinary LH point-of-care testing demonstrates a comparable performance among other ovulation monitoring methods for timing intrauterine insemination and confirming sufficient ovulation induction before oocyte retrieval during in vitro fertilization. Second, pregnancy POCT should be considered in clinical situations where rapid diagnosis of pregnancy is needed for treatment decisions, and laboratory analysis cannot meet the required turnaround time. Third, PROM testing using commercial kits alone is not recommended without clinical signs of rupture of membranes, such as leakage of amniotic fluid from the cervical opening. Finally, fetal scalp lactate is used more than fetal scalp pH for fetal acidosis due to higher success rate and low volume of sample required.

Conclusions

This revision of the AACC Academy POCT guidelines provides recommendations for best practice use of POCT in fertility and reproduction.

Comparative analysis of Insulin-like growth factor binding protein-1, placental alpha-microglobulin-1, phenol and pH for the diagnosis of preterm premature rupture of membranes between 20 and 36 weeks

AIM

Preterm premature rupture of membranes (PPROM) is responsible for approximately one-third of premature births worldwide, and although the diagnosis is often straightforward, this condition can still present difficulties. The purpose of this research was to compare the accuracy of several PPROM diagnostic tests.

METHODS

A total of 94 pregnant women with clinical suspicion of PPROM who were between 20 and 36 weeks of pregnancy were examined by vaginal speculum, and tests were performed for phenol, pH, insulin-like growth factor binding protein-1 (IGFBP-1) and placental alpha-microglobulin-1 (PAMG-1). All patients were followed up until the diagnosis was fully defined, and a diagnosis of PROM was confirmed by a definitive evolution of the clinical symptoms (visualization of vaginal amniotic fluid or persistence of oligohydramnios).

RESULTS

After excluding the cases that could not be definitively diagnosed, a good diagnostic performance of the immunochromatographic tests was observed that was superior to that of the clinical tests. Similar accuracies were observed for IGFBP-1 (98.7%) and PAMG-1 (93.9%). However, while the IGFBP-1 test differed from a vaginal pH ≥7 (88.9%) and the phenol test (85.7%), this did not occur for the PAMG-1 test. The performance of the tests was modified only by the presence of bleeding (with lower specificity rates for pH and phenol), without interference of gestational age or maternal morbidities.

CONCLUSION

Immunochromatographic tests are good tools but should be used sparingly in resource-poor settings because they are expensive, and there is no significant difference between PAMG-1 and traditional tests.

A high concentration of fetal fibronectin in cervical secretions increases the risk of intra-amniotic infection and inflammation in patients with preterm labor and intact membranes

Objective To determine whether the risk of intra-amniotic infection/inflammation and spontaneous preterm delivery (SPTD) varies as a function of the concentration of cervical fetal fibronectin (fFN) in patients with preterm labor and intact membranes. Methods This prospective study included 180 patients with preterm labor and intact membranes who had a sample collected for quantitative fFN measurement and underwent amniocentesis. Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas. Intra-amniotic inflammation was defined as an amniotic fluid matrix metalloproteinase-8 concentration >23 ng/mL. Results (1) The prevalence of intra-amniotic infection/inflammation and SPTD within 7 days was 32.2% (58/180) and 33.9% (61/178), respectively; (2) The higher the fFN concentration, the greater the risk of intra-amniotic infection/inflammation and SPTD within 7 days (P<0.001, respectively); (3) An fFN concentration 150 ng/mL had a better diagnostic performance than an fFN 50 ng/mL in the identification of intra-amniotic infection/inflammation and SPTD within 7 days; (4) Among the patients with an fFN <50 ng/mL, intra-amniotic infection/inflammation was identified in 7.6% (6/79) of patients and 66.7% (4/6) delivered within 7 days. Conclusion The higher the concentration of fFN, the greater the risk of intra-amniotic infection/inflammation and SPTD in patients with preterm labor and intact membranes.

A Sanitary Pad for Self-Assessment of Rupture of Membranes

BACKGROUND

Multistep immunoassay kits for the diagnosis of rupture of membranes are relatively complex and are not designed to be used by pregnant women themselves. These kits require procedural steps of specimen extraction and preparation. We evaluated the ability of a sanitary pad containing a qualitative immunoassay for alpha-fetoprotein (AFP) to serve as a one-step self-test to detect amniotic fluid leakage.

TECHNIQUE

Four sets of pads were evaluated. The pads in the study set were worn by 288 pregnant women with confirmed rupture of membranes. Three controls were evaluated: 1) pads worn by 93 pregnant women with intact membranes, 2) additional pads instilled with urine specimens obtained from the 381 women described previously (study set plus control set 1), and 3) pads instilled with semen collected from 40 men.

EXPERIENCE

All 288 pads that absorbed amniotic fluid had positive results. Approximately half of the pads absorbed with normal vaginal discharge had a sufficient amount to yield valid results, which were all negative. All 381 pads with instilled urine and all 40 pads with instilled semen had negative results.

CONCLUSION

An immunoassay for AFP, embedded in a pad, appears to be a feasible and reproducible self-test for the detection of rupture of membranes.