Elevated Maternal Homocysteine and Coagulation Markers Linked to SGA in Pregnancies with GDM and Preeclampsia: Study

Could a routine blood test pinpoint pregnancies at increased risk for delivering a small-for-gestational-age (SGA) infant—even when gestational diabetes (GDM) and preeclampsia (PE) are already diagnosed? Recent research explored how maternal homocysteine (Hcy) and coagulation–fibrinolysis biomarkers relate to birthweight and placental function in this double-threat maternal population.

Study Overview: Targeting High-Risk Pregnancies

This single-center retrospective cohort study reviewed 760 women carrying singletons and diagnosed with both GDM and PE. Researchers compared levels of homocysteine (Hcy) and several coagulation–fibrinolysis markers (TAT, TM, PIC, tPAI-C, and the TAT/PIC ratio), investigating associations with SGA birth—defined as birthweight under the 10th percentile for gestational age.

Main Findings: Elevated Markers, Increased SGA Risk

SGA births occurred in 22% of the cohort.

Higher levels of Hcy, TAT, TM, tPAI-C, and the TAT/PIC ratio were all independently associated with an increased risk of SGA, even after adjusting for confounders like maternal age, BMI, and glycemic status.

Notably, the TAT/PIC ratio showed a clear gradient: SGA rates climbed from 10.5% in the lowest to 33.7% in the highest quartile, with a more-than-twofold risk in the top group.

The association with PIC alone was inconsistent and not statistically significant after full adjustment.

Placental Vascular Dysfunction: A Key Link in the Pathway

Beyond birthweight, elevated Hcy, TAT, TM, tPAI-C, and TAT/PIC ratio aligned with:

Higher umbilical artery pulsatility index (UA-PI), indicating increased placental vascular resistance.

Lower cerebroplacental ratio (CPR), a Doppler sign of cerebral blood flow redistribution—a common fetal adaptation to placental insufficiency.

Higher rates of fetal growth restriction (FGR) diagnosed antenatally.

These results support a model where SGA in GDM/PE pregnancies reflects not just metabolic or glycemic disturbance, but a broader maternal vascular and hemostatic disruption affecting placental function.

Clinical Takeaways and Considerations

Clinicians managing GDM/PE should recognize that SGA risk remains significant and multifactorial, even with typically growth-promoting metabolic disease like GDM. Elevations in maternal homocysteine and coagulation–fibrinolysis markers may help risk-stratify this subset, though routine biomarker screening is not yet recommended—the exploratory nature of some measures (like TAT/PIC ratio) means further validation is needed.

For now, the study underscores the importance of integrated maternal-fetal surveillance in women with both GDM and PE, looking beyond glycemic control to vascular and placental health.

Conclusion

Elevated maternal homocysteine and coagulation–fibrinolysis biomarkers, especially the TAT/PIC ratio, are associated with an increased risk of SGA and placental vascular dysfunction in women with GDM and preeclampsia. Prospective work is needed to determine if these markers might one day guide personalized monitoring or intervention.

Key Points

Elevated maternal Hcy, TAT, TM, tPAI-C, and the TAT/PIC ratio independently predict higher SGA risk in pregnancies with GDM and PE.

These biomarkers also signal increased placental vascular resistance and higher fetal growth restriction risk.

PIC alone was not a consistent marker for SGA after adjustment.

SGA risk rises more than twofold in the highest quartile of the TAT/PIC ratio.

The TAT/PIC ratio holds promise as a composite marker but requires external validation before clinical use.

Citation:

Zhang Y, Sun Z. Association of maternal homocysteine and coagulation–fibrinolysis biomarkers with small-for-gestational-age birth in pregnancies complicated by gestational diabetes mellitus and preeclampsia. BMC Pregnancy and Childbirth. 2026; in press. DOI: https://doi.org/10.1186/s12884-026-10131-2