Blood gene transcript signature profiling in pregnancies resulting in preterm birth: A systematic review

OBJECTIVE

To pursue a systematic review and summarise the current evidence for the potential of transcriptome molecular profiling in investigating the preterm phenotype.

STUDY DESIGN

We systematically reviewed the literature, using readily available electronic databases (i.e. PubMed/Medline, Embase, Scopus and Web of Science) from inception until March 2020 to identify investigations of maternal blood-derived RNA profiling in preterm birth (PTB). Studies were included if circulating coding or non-coding RNA was analysed in maternal blood during pregnancy and/or at delivery. Interventional trials were not included. The primary outcome was the availability of whole genome expression patterns evaluated in pregnancies resulting in preterm deliveries.

RESULTS

A total of 35 articles were included in the final analysis. Most of the studies were conducted in high-income countries and published in the last decade. Apart from spontaneous PTB, a variety of phenotypes leading to preterm delivery were reported. Differences in sampling methods, target gene selection and laboratory protocols severely limited any quantitative comparisons. Most of the studies revealed that gene expression profiling during pregnancy has high potential for identifying women at risk of spontaneous and/or non-spontaneous PTB as early as in the first trimester.

CONCLUSION

Assessing maternal blood-derived transcriptional signatures for PTB risk in pregnant women holds promise as a screening approach. However, longitudinally followed, prospective pregnancy cohorts are lacking. These are relevant for identifying causes leading to PTB and whether prediction of spontaneous PTB or co-morbidities associated with PTB is achievable. More emphasis on widely employed standardised protocols is required to ensure comparability of results.

Serial Amnioinfusion as Regenerative Therapy for Pulmonary Hypoplasia in Fetuses With Intrauterine Renal Failure or Severe Renal Anomalies: Systematic Review and Future Perspectives

The aim of this study was to investigate the effect of serial amnioinfusion therapy (SAT) for pulmonary hypoplasia in lower urinary tract obstruction (LUTO) or congenital renal anomalies (CRAs), introduce patient selection criteria, and present a case of SAT in bilateral renal agenesis. We conducted a search of the MEDLINE, EMBASE, Web of Science, and Scopus databases for articles published from database inception to November 10, 2017. Eight studies with 17 patients (7 LUTO, 8 CRA, and 2 LUTO + CRA) were included in the study. The median age of the mothers was 31 years (N=9; interquartile range [IQR], 29-33.5 years), the number of amnioinfusions was 7 (N=17; IQR, 4.5-21), gestational age at first amnioinfusion was 23 weeks and 4 days (N=17; IQR, 21-24.07), gestational age at delivery was 32 weeks and 2 days (N=17; IQR, 30 weeks to 35 weeks and 6.5 days), birthweight of newborns was 3.7 kg (N= 9; IQR, 2.7-3.7 kg), Apgar score at 1 minute was 2.5 (N=8; IQR, 1-6.5), and Apgar score at 5 minutes was 5.5 (N=8; IQR, 0-7.75). In conclusion, SAT may provide fetal pulmonary palliation by reducing the risk of newborn pulmonary compromise secondary to oligohydramnios. Multidisciplinary research efforts are required to further inform treatment and counseling guidelines. We propose a multidisciplinary approach to prenatal classification of fetuses with LUTO to inform patient selection.