No blood test can accurately tell if a pregnant or recently pregnant woman has a blood clot. All pregnant women with a suspected clot should continue to have imaging investigations as per current UK guidelines.
This NIHR-funded study recruited 328 pregnant or postpartum women with a suspected blood clot in the lung (pulmonary embolism) or leg (deep vein thrombosis). They had a blood test to measure the levels of 13 biomarkers, such as the D-dimer, to see if they could rule a blood clot in or out. It was hoped that this could reduce the number of women who would need confirmation from a scan, and so decrease their exposure to radiation.
None of the tests were accurate enough. The range of levels for each biomarker overlapped between women with and without a clot.
Hunt BJ, Parmar K, Horspool K, et al. The DiPEP (Diagnosis of PE in Pregnancy) biomarker study: An observational cohort study augmented with additional cases to determine the diagnostic utility of biomarkers for suspected venous thromboembolism during pregnancy and puerperium. Br J Haematol. 2018;180(5):694-704.
If fetal brain abnormality is suspected on a pregnancy ultrasound, following this with in-utero MRI (iuMRI) improves diagnostic accuracy. This sequence could allow more informed discussions and decision-making around whether to continue with or terminate a pregnancy.
The NIHR funded study included 565 women of 18 weeks’ pregnancy or more who received ultrasound followed by iuMRI. Diagnoses were confirmed either by postnatal imaging of the baby or at post-mortem examination.
Overall iuMRI gave the correct diagnosis for 93% of scans compared to only 68% of ultrasounds. The accuracy of ultrasound declined above 24 weeks of pregnancy, whereas iuMRI performed well at all times. Clinicians reported that iuMRI scan results caused them to modify their future care planning in over 20% of cases.
Cost effectiveness was not assessed and iuMRI scans are not as widely available as ultrasound. Therefore, resource issues are an important consideration when judging whether or how to implement iuMRI into the diagnostic pathway.
New research published in JAMA has attempted to answer the question of what proportion of fetuses and infants of women in the United States with laboratory evidence of possible Zika virus infection during pregnancy have birth defects.
“Conclusions and Relevance: Among pregnant women in the United States with completed pregnancies and laboratory evidence of possible recent Zika infection, 6% of fetuses or infants had evidence of Zika-associated birth defects, primarily brain abnormalities and microcephaly, whereas among women with first-trimester Zika infection, 11% of fetuses or infants had evidence of Zika-associated birth defects. These findings support the importance of screening pregnant women for Zika virus exposure”
Source: Honein MA, Dawson AL, Petersen EE et al. Birth Defects Among Fetuses and Infants of US Women With Evidence of Possible Zika Virus Infection During Pregnancy JAMA. 2017 Jan 3;317(1):59-68
The Newborn Blood Spot Failsafe Solution (NBSFS) IT system, which flags up babies who may have missed screening, is now complete in all parts of England. The NHS Newborn Blood Spot (NBS) Screening Programme uses a heel prick test to screen newborn babies for 9 rare but serious conditions. Babies who test positive can then be treated early, improving their health and, in some cases, preventing severe disability or even death. For some time, the system has been able to identify babies who have had no NBS screening at all, but until now it couldn’t always track babies who needed a repeat test.
Link to Public Health England Blood Spot Screening Programme here
PHE Press release: Screening newborns for muscle wasting condition not recommended
Newborn babies should not be screened for the muscle wasting condition Duchenne Muscular Dystrophy, according to the UK’s independent expert screening committee.
The current test available for the condition incorrectly identifies some babies as having the condition and misses others who go on to develop the disease
High-throughput non-invasive prenatal testing for fetal RHD genotype | 1-Recommendations | Guidance and guidelines | NICE
1.1 High-throughput non‑invasive prenatal testing (NIPT) for fetal RHD genotype is recommended as a cost-effective option to guide antenatal prophylaxis with anti‑D immunoglobulin, provided that the overall cost of testing is £24 or less. This will help reduce unnecessary use of a blood product in pregnant women, and conserve supplies by only using anti‑D immunoglobulin for those who need it.
1.2 Cost savings associated with high-throughput NIPT for fetal RHD genotype are sensitive to the unit cost of the test, additional pathway costs and implementation costs. Trusts adopting NIPT should collect and monitor the costs and resource use associated with implementing testing to ensure that cost savings are achieved (see section 6.1).