ObjectiveTo determine teratogenicity of beta-blockers in early pregnancy. MethodsWe searched PubMed, EMbase, Cochrane Clinical Trials, clinicaltrials.gov, CBM, Wanfang database, and CNKI from establishment of each database to December 2014. We evaluated the quality of included literature. Statistical analysis was conducted in RevMan5.3 software. ResultsFifteen population-based case-control or cohort studies were identified. The score of included studies changed from 5-7 points. Based on meta-analysis, first trimester oral beta-blocker use showed no increased odds of all or major congenital anomalies. While in analysis examining organ-specific malformations, statistically increased odds of cardiovascular (CV) defects with OR 2.21 and 95% CI 1.63 to 3.01, cleft lip/palate (CL/P) with OR 3.11 and 95% CI 1.78 to 9.89, and neural tube (NT) defects with OR 3.56 and 95% CI 1.19 to 10.67 were observed. ConclusionCausality is difficult to interpret given small number of heterogeneous studies and possibility of biases. Given the frequency of this exposure in pregnancy, further research is needed.
Objective To systematically review the association between prenatal exposure to dichlorodiphenyltrichloroethane (DDT) or polychlorinated biphenyls (PCBs) and the risk of congenital anomalies. Methods PubMed, EMbase, WanFang Data, VIP and CNKI databases were electronically searched to collect case-control studies on the relationship between prenatal exposure to DDT or PCBs and congenital anomalies from inception to February 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using Stata 13.0 software. Results A total of 14 studies involving 2 238 infants with defect and 2 335 infants without defect were included. The results of meta-analysis showed that: the prenatal exposure to high level of DDT increased the incidence of cryptorchidism (OR=1.12, 95% CI 1.09 to 1.15, P<0.001). However, DDT exposure had no correlation to hypospadias and neural tube defects. The associations between prenatal exposure to PCBs and cryptorchidism, hypospadias, neural tube defects were not discovered. Conclusion Prenatal exposure to high levels of DDT may be a risk factor for cryptorchidism. Due to limited quality and quantity of the included studies, more high-quality studies are needed to verify above conclusion.