Objective: To investigate the clinical effect and safety of heparin in treating fetal growth restriction (FGR).
Methods: A total of 107 women diagnosed with FGR were randomized into three groups. Group 1 (standard heparin group, n = 37) received 50 - 75 mg standard heparin added to 500 ml 5% glucose sodium chloride, infused intravenously in 6 - 8 hours. Group 2 (low molecular weight heparin group, n = 31) received 0.2 - 0.4 ml low molecular weight heparin given by subcutaneous injection. Control group (n = 39) received 20 ml dan-shen added to 500 ml low-molecular-weight dextran infused intravenously. Fetal growth indices, biophysical score, umbilical artery blood flow, count of platelet (PLT), prothrombin time (PT), activated partial thromboplastin time (APTT), 1-minute Apgar score, body weight and gestational age of the neonates were measured. Babies prognosis was followed-up.
Results: (1) Height of fundus of uterus was obviously increased per week in the groups of standard heparin (0.7 +/- 0.6) cm and low molecular weight heparin [(0.7 +/- 0.6) cm]] vs. control group [(0.5 +/- 0.4) cm, P < 0.05]. Biparietal diameter of fetus increased in standard heparin [(2.4 +/- 0.7) mm] and low molecular weight heparin [(2.5 +/- 0.8) mm] groups vs. control [(1.7 +/- 0.6) mm, P < 0.05]. The femur length, head circumference and abdominal circumference of fetus were significantly longer in heparin treated patients than in control group (P < 0.05). (2) Biophysical score improved in groups of standard heparin (9.7 +/- 0.8) and low molecular weight heparin (9.6 +/- 0.6) vs. control group (8.9 +/- 0.7) (P < 0.05). (3) Umbilical blood S/D ratio decreased in standard heparin (2.5 +/- 0.5) and low molecular weight heparin (2.4 +/- 0.5) groups vs. control group (2.9 +/- 0.6) (P < 0.05). Pulsatile index (PI) and resistance index (RI) were significantly lower also (P < 0.05).(4) Rate of one minute Apgar score (8 - 10) was 86% in group 1, 87% in group 2 and 74% in control group, respectively. Body weight of the neonates was significantly increased in group 1(3100 +/- 256 g) and in group 2 [(3080 +/- 225) g] vs. [(2580 +/- 304) g] in control group (P < 0.05). Gestational age was prolonged in group 1 [(38 +/- 3) w] and group 2 [(38 +/- 4) w] vs. control group [(37 +/- 4) w, P < 0.05]. (5) Incidence of term small for gestational age infant in groups of standard heparin and low molecular weight heparin was 5% and 6%, respectively, significantly lower than those in the control group (18%) (P < 0.05). (6) No difference was shown in PLT, PT and APTT before and after heparin treatment (P > 0.05). (7) There was no difference in fetal growth indices, biophysical score, umbilical blood, neonatal outcome between standard heparin and low molecular heparin groups.
Conclusions: Heparin can improve placenta function and obviously increase body weight of fetuses and neonates. It is safe for both pregnant women and their fetuses.