Efficacy of Normobaric High-Flow Oxygen Therapy Combined with Low Molecular Weight Heparin in the Management of Fetal Growth Restriction: A Prospective Cohort Study.

OBJECTIVE

This study investigated the clinical efficacy of adding normobaric high-flow oxygen therapy (NHFOT) to low molecular weight heparin (LMWH) and standard supportive care for the management of the present FGR cohort, idiopathic fetal growth restriction (FGR).

METHODS

This prospective cohort study enrolled 117 women with idiopathic FGR, representing a spectrum of gestational ages at diagnosis, at a single center between July 2022 and June 2025. All participants received standard supportive care including low-flow nasal oxygen (2-5 L/min, 30-40% O2) and intravenous nutritional support (vitamin C 4 vials/8 mL in 500 mL 5% dextrose plus 200 mL compound amino acids daily for 7 days). Participants were assigned to three groups based on shared decision-making: Group 1 (n=32) received standard care only; Group 2 (n=37) received standard care plus subcutaneous LMWH (4000 IU daily); Group 3 (n=48) received standard care plus LMWH and NHFOT (8-10 L/min, 95% O2, 45 min/day).

RESULTS

Compared with Group 1, Group 3 showed a modest but statistically significant prolongation of gestational age at delivery (+2.5 days; 267.5 vs 265.0 days; P=0.002), higher median birth weight (+240 g; 2600 vs 2360 g; P<0.001), higher FGR cure rate (45.83% vs 18.75%; P=0.042), and lower low birth weight rate (33.33% vs 65.63%; P=0.013). However, no significant differences in FGR cure rate were observed between Group 3 and Group 2 (45.83% vs 32.43%; P=0.213). No significant differences were found in preterm birth rates or umbilical cord blood gas parameters among groups.

CONCLUSION

Our findings indicate that in a cohort of idiopathic FGR encompassing a range of gestational ages, combining NHFOT with LMWH may improve fetal weight and reduce LBW risk compared to standard care alone. However, no conclusive additional benefit over LMWH alone was observed for the primary cure outcome.

CLINICAL TRIAL NUMBER: MR-45-22-008098.