ABSTRACT
Objective:To investigate the clinical features and perinatal outcomes of twin pregnancies with complete placenta previa (CPP).Methods:We conducted a retrospective study on 266 women with CPP, including 62 twin pregnancies (twins group) and 204 singleton pregnancies (singleton group), who gave birth in Peking University Third Hospital from January 2012 to December 2020. T-test, nonparametric test and Chi-square test were adopted for univariate analysis. Differences between the two groups regarding clinical features and perinatal outcomes were compared using multivariate logistic regression or multivariate linear regression. Results:The incidence of twin pregnancy with CPP was 2.11% (62/2 937). Placenta accreta spectrum disorders (PAS) accounted for 48.4% (30/62) and 53.9% (110/204) in the twin and singleton group, respectively, but the difference was not statistically significant ( χ 2=0.58, P>0.05). In terms of antepartum hemorrhage, the proportion of women affected, those with first onset <29 weeks, amount of bleeding ≥200 ml, and the number of episodes of bleeding ≥3 were significantly higher in the twin group than those in the singletons [56.5% (35/62) vs 39.7% (81/204); 35.5% (22/62) vs 12.7% (26/204); 17.7% (11/62) vs 4.9% (10/204); and 21.0% (13/62) vs 10.3% (21/204), χ 2=5.42, 16.62, 10.78, and 4.86, respectively, all P<0.05]. Multivariate Logistic regression analysis showed that compared with the singleton group, the twin group was at higher risk of antepartum hemorrhage volume >200 ml, the number of antepartum hemorrhage episodes ≥3, preterm delivery before 34 weeks and 32 weeks, emergency cesarean section, and emergency cesarean section caused by antepartum hemorrhage [a OR(95% CI)=4.36(1.17-16.30), 3.15(1.01-9.79), 17.24(5.36-55.46), 9.85(2.32-41.77), 3.98(1.72-9.20), and 3.10(1.22-7.85), respectively, all P<0.05]. Multivariate linear regression analysis showed that the gestational week at the emergency cesarean section in the twins group was about 2.22 weeks (0.17-4.27 weeks) earlier than that in the singletons. The postpartum hemorrhage amount and the risk of postpartum hemorrhage after cesarean section, infusion of red blood cells, and hysterectomy did not differ significantly between the two groups. Conclusions:Compared with singleton pregnancies, the proportion of preterm delivery, cesarean sections, especially those caused by antepartum hemorrhage, is significantly higher among twin pregnancies combined with CPP. Accordingly, preterm delivery should be actively prevented, and the timing of cesarean section should be individualized according to the condition of the mothers and babies, and early delivery may be considered.
ABSTRACT
ObjectiveTo explore the bone anabolic effects after a single local injection of simvastatin into femoral cavities of osteoporotic rats.MethodsThirty-six female SD rats(3 months old,body weight 250-300 g) were ovariectomized(OVX) and low-calcium-diet fed for 3 months,OVX rats were randomized into 3 groups(n=12).Left femurs of group A,B and C were injected with 0,5 and 10 mg simvastatin,respectively.Half of the rats in each group were randomly euthanized separately 1 and 5 months after simvastatin injection.Left femurs were taken out for bone mineral density (BMD) assessment with dual energy X-ray absorptiometry,bone histomorphometic changes were analysized by Micro-CT,and two kinds of biomechanical tests were used to evaluate the osteogenic effects.ResultsOne and five months after injection,BMD in mid-diaphysis significantly increased in simvastatin-injected groups compared to the control group.For Micro-CT analysis,significant increase in total bone volume/total tissue volume,cortical wall thickness,trabecular thickness,trabecular number,and a significant decrease in trabecular spacing were observed in simvastatin-injected groups compared to the control group.For both biomechanics (the three-pointbreaking test of condyles and axial compressive testing of proximal femur),the values were significantly higher in simvastatin-injected groups than the control group.ConclusionLocal simvastatin treatment showed a positive effect on improving mechanical strength,structure of osteopenic femurs and BMD.Our findings may provide a new strategy for the prevention and treatment of osteoporosis,especially for osteoporotic fractures.