Generally, doctors hospitalize pregnant women with threatened preterm labor (TPTL), a condition where an expectant mother experiences persistent premature contractions. Yet only five percent of women with TPTL actually deliver a premature baby. Now, a new diagnostic tool was found to be 70 percent accurate in predicting whether a woman with TPTL would give birth prematurely. “A lot of TPTL women are unnecessarily hospitalized,” said Dr. Stephen Lye, Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto. “We want to develop a test that can differentiate between true and false labor so that women in true labor can receive the appropriate medical care while women in false labor will receive supportive care and be discharged.”

The Plight of Premature Babies

About eight to 11 percent of all pregnancies worldwide result in a preterm birth, which is a main cause of mortality in the developed world. Although medical advances have increased survival rates for preemies, these tiny babies often suffer cognitive impairments, respiratory disorders, blindness, deafness, and other physical difficulties. Even later in their development, they remain vulnerable to health problems. For the current study, the researchers studied whole blood gene expression as a possible indicator of spontaneous preterm birth.

To begin their study, the researchers collected peripheral blood from 154 women with TPTL during hospital admission (before medical treatment). Then, the researchers analyzed differential whole blood gene expression, comparing the samples from the 48 women who gave birth within 48 hours of admission and the 106 women who did not. Finally, they performed fetal fibronectin (fFN) tests on participants, an existing preterm diagnostic tool, which is known to be prone to false positives.

The researchers found total leukocyte and neutrophil counts to be significantly higher (35 percent and 41 percent, respectively) in the women who gave birth prematurely compared to the women who did not. Yet, within a subset of the women, no differences existed in the urine, vaginal, and placental microbiology and histopathology reports. Finally, when the researchers combined a set of nine genes with clinical blood data, they were able to correctly classify 70 percent of participants as giving birth prematurely within 48 hours of hospital admission.

Why is this important? The new blood analysis test outperformed the fFN test when all results were compared. Plus, the new test could easily be performed as part of routine blood work, suggesting it might easily replace the fFN.

Source: Heng YJ, Pennell CE, Chua HN, Perkins JE, Lye SJ. Whole Blood Gene Expression Profile Associated with Spontaneous Preterm Birth in Women with Threatened Preterm Labor. PLoS ONE. 2014.