Cervical length at 30-32 weeks and the risk of Cesarean delivery in twin pregnancies.

OBJECTIVES: To estimate the association between the cervical length (CL) measurement at 30-32 weeks and the mode of delivery in twin pregnancies. METHODS: This was a retrospective study of a cohort, from 2005-2010, of 265 twin pregnancies with a CL measurement at 30-32 weeks. We compared the CL measurement at 30-32 weeks based on mode of delivery. We then analyzed our data across four subgroups, based on the CL measurement quartiles at 30-32 weeks. We performed this analysis in all patients, and also performed a planned subgroup analysis of 130 patients who attempted a vaginal delivery. RESULTS: In all patients, including those who attempted a vaginal delivery, the mean CL at 30-32 weeks was significantly shorter in women who delivered vaginally compared with women who had a Cesarean section. The likelihood of Cesarean delivery increased significantly with increasing CL measurement across the groups defined by measurement quartiles. On adjusted analysis controlling for maternal age, race, in-vitro fertilization, chorionicity, induction of labor and prior vaginal delivery, the CL measurement at 30-32 weeks was independently associated with mode of delivery. CONCLUSIONS: In twin pregnancies, the CL at 30-32 weeks is significantly associated with the likelihood of Cesarean delivery. A longer CL may represent underdevelopment of the uterus, leading to a higher risk of Cesarean delivery in labor at term.

Intravaginal misoprostol versus Foley catheter for labour induction: a meta-analysis.

BACKGROUND: There are a number of agents used for cervical ripening prior to the induction of labour. Two commonly used agents are intravaginal misoprostol and a transcervical Foley catheter. OBJECTIVE: To review the evidence comparing misoprostol and transcervical Foley catheter placement for induction of labour, and perform a meta-analysis comparing these two induction agents. SEARCH STRATEGY: We conducted database searches of PubMed, Embase, the Cochrane Library Database, and the ClinicalTrials.gov website. Bibliographies of all relevant articles were reviewed. SELECTION CRITERIA: Prospective, randomised trials comparing the use of intravaginal misoprostol and transcervical Foley catheter for the purpose of cervical ripening and induction of labour were included. We excluded studies in which the patients in these two intervention groups also received other induction agents concurrently, such as oral misoprostol, oxytocin, or other prostaglandins. DATA COLLECTION AND ANALYSIS: The primary outcomes selected were time to delivery, and the rates of caesarean section, uterine tachysystole, and chorioamnionitis. Random-effects generalised linear models with a poisson distribution and log link function were used to compare the two induction agents across the studies. MAIN RESULTS: Nine studies (1603 patients) were identified as eligible to be included in this meta-analysis. There were no significant differences in the mean time to delivery (mean difference 1.08 ± 2.19 hours shorter for misoprostol, P = 0.2348), the rate of caesarean delivery (RR 0.991; 95% CI 0.768, 1.278), or in the rate of chorioamnionitis (RR 1.130; 95% CI 0.611, 2.089) between women who received misoprostol compared with transcervical Foley catheter. Patients who received misoprostol had significantly higher rates of tachysystole compared with women who received a transcervical Foley catheter (RR 2.844; 95% CI 1.392, 5.812). CONCLUSIONS: Intravaginal misoprostol and transcervical Foley catheter have similar effectiveness as induction agents. Transcervical Foley catheter is associated with a lower incidence of tachysystole.

Association between small for gestational age and paternally inherited 5' insulin haplotypes.

OBJECTIVE: To test the association between small for gestational age and polymorphisms in the insulin gene in newborns and their mothers, as well as the effect of the parental transmission of haplotypes. SUBJECTS: Pairs of healthy African-American full-term newborns (N=207) and mothers were recruited from Memphis TN and Jackson MS with birth weights ranging from 2210 to 4735 g. METHODS: Six single nucleotide polymorphisms (SNPs) located in the insulin (INS) and insulin-like growth factor 2 (IGF2) genes were genotyped in mothers and newborns. Haplotypes composed of three SNPs in the 5' region of the INS-IGF2 locus were computationally inferred. Odds ratios for risk of small for gestational age (SGA) birth were calculated for individual SNPs and inferred haplotypes in the newborns and in the mothers using logistic regression. For 162 mother--newborn pairs the parental transmission of the haplotypes could be inferred, and the risks for SGA birth were calculated for the three common haplotypes in this sample. RESULTS: Three INS SNPs exhibited significant association with risk for SGA birth. The SNP alleles associated with increased risk for SGA were opposite in the maternal and newborn genomes, implying opposing influences on the rate of fetal growth. Consistent with these results, haplotypes composed of complementary nucleotide sequences (CAC at rs3842738, rs689 and rs3842748, respectively, in the newborn versus GTG in the mother) were significantly associated with risk for SGA birth. In analyses of haplotypes according to parental transmission, the same trend in risk for SGA was observed for both maternally and paternally transmitted haplotypes, although a significant difference in risk was observed only for paternally transmitted haplotypes. CONCLUSION: Polymorphisms near the 5' end of the INS-IGF2 locus are significantly associated with risk for SGA birth with a major effect due to the paternally transmitted haplotype, which is preferentially expressed due to imprinting.