[Effect of heparin on fetal growth restriction]

To investigate the clinical effect and safety of heparin in treating fetal growth restriction (FGR).

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.

(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.

Heparin can improve placenta function and obviously increase body weight of fetuses and neonates. It is safe for both pregnant women and their fetuses.