Association Between Second‐Trimester Cervical Length and Spontaneous Preterm Birth in Twin Pregnancies

Objective. The purpose of this study was to define normal second‐trimester cervical length (CL) measurements and to estimate the association between second‐trimester CL and spontaneous preterm birth (SPTB) in twin pregnancies. Methods. A retrospective cohort of 309 asymptomatic patients with twin pregnancies who had routine outpatient CL assessment in the second trimester was studied. We looked at the gestational age periods of 16 to 17 6/7, 18 to 19 6/7, 20 to 21 6/7, and 22 to 23 6/7 weeks. We estimated the association between the CL measurement during each period and SPTB. A short CL was defined both as a CL at or below the 10th percentile for gestational age and 25 mm or less. We also performed regression analyses controlling for a number of clinically important factors: maternal age, chorionicity, in vitro fertilization, multifetal reduction, prior term births, prior preterm births, prepregnancy body mass index, and cerclage. Results. The CL measurement at 16 to 17 6/7 weeks was not associated with gestational age at delivery or SPTB. At 18 to 19 6/7 and 20 to 21 6/7 weeks, the CL measurement was not significantly associated with gestational age at delivery or SPTB before 28 and 32 weeks. There was an association with SPTB before 35 weeks. At 22 to 23 6/7 weeks, the CL measurement had a significant association with gestational age at delivery and SPTB before 28, 32, and 35 weeks (P < .05). A short CL at 22 to 23 6/7 weeks was significantly associated with SPTB before 32 and 35 weeks (P < .05). Conclusions. In second‐trimester twin pregnancies, the strongest association between CL and SPTB is at 22 to 23 6/7 weeks.     

Familial abnormalities of endocannabinoid signaling in schizophrenia

Objectives: Epidemiological and experimental evidence suggests that the endocannabinoid system plays a pathophysiological role in schizophrenia. This is reflected by elevated cerebrospinal levels of the endocannabinoid anandamide in schizophrenia and its initial prodromal states.

Methods: We analyzed plasma concentrations of anandamide, 2-arachidonoyl-sn-glycerol, palmitoylethanolamide and oleoylethanolamide from 25 twin pairs discordant for schizophrenia, six discordant for bipolar disorder and eight healthy twin pairs to determine hereditary traits.

Results: Twin pairs discordant for schizophrenia or bipolar disorder had significantly higher levels of anandamide and palmitoylethanolamide compared to healthy twins (both P?P?=?0.042) and 2-arachidonoyl-sn-glycerol levels (P?=?0.049) than twins who remained healthy.

Conclusions: We suggest that the protective upregulation of endocannabinoid signalling reflects either a hereditary trait or mirrors a modulating response to genetically influenced cerebral function involving, e.g., other neurotransmitters or energy metabolism.     

2017年美国放射学会多胎妊娠超声检查指南解读

        由于辅助生殖技术广泛应用以及高龄孕妇增多,多胎妊娠的发生率呈上升趋势。多胎妊娠的女性通常比单胎妊娠的女性需要更多的超声检查。大多数女性至少会进行1次早孕期检查、孕12~14周颈项透明层（nuchal translucency,NT）检查、孕18~22周解剖结构筛查,以及晚孕期1次或多次检查以评估其生长情况。每次超声检查的目标因孕龄的不同而不同,检查次数尚无统一标准。2017年美国放射学会（American College of Radiology,ACR）发布了关于多胎妊娠超声检查适用标准的指南［1］。因双胎代表了98%的多胎妊娠,且绝大多数数据与双胎妊娠有关,故该指南几乎完全集中于双胎妊娠。本文将对其中的要点进行解读。     

Selective termination in dichorionic twins discordant for congenital defect

Objective

To evaluate the perinatal outcome of selective termination in dichorionic twins discordant for congenital defect, performed at the Hospital General Universitario Gregorio Marañon.

Study design

Twenty-eight dichorionic twins with an anomalous fetus were included from May 2008 to February 2011. Intracardiac KCl (1–2 ml; 15 mEq/ml) under ultrasonographic guidance was used in all procedures. Congenital defect, gestational age at the procedure, incidence and perinatal outcome were retrieved.

Results

Selective termination was performed in 14 (50%) cases of structural defects with normal karyotype and in 14 (50%) cases of chromosomal abnormality, 13 of them (92.8%) trisomy 21. Median gestational age at the procedure was 17.8 weeks (range 14.5–24; SD 2.3), and 12 (42.8%) were performed before 18 weeks. The presenting fetus was terminated in 11 cases (39.3%). Selective termination was followed by the subsequent delivery of a viable infant in 27 out of 28 cases (96.4%). Fetal loss before 24 weeks occurred in 1 case (3.6%). Median gestational age at delivery was 38 weeks (range 24.1–40.1; SD 3.8). Twenty-four (88.9%) were delivered >34 weeks and 1 (3.7%) before 28 weeks.

Conclusion

Selective termination in dichorionic twins discordant for congenital defect is a safe procedure with low risk of unintended fetal loss. This option is a reasonable alternative to expectant management or termination of the whole pregnancy.     

Preliminary evidence of a noncausal association between the X-chromosome inactivation pattern and thyroid autoimmunity: a twin study

An increased frequency of skewed X-chromosome inactivation (XCI) is found in clinically overt autoimmune thyroid disease (AITD) compared with controls. Whether skewed XCI is involved in the pathogenesis of autoantibodies to thyroid peroxidase (TPOAb) in euthyroid subjects is unknown. To examine the impact of XCI on the serum concentration of TPOAb, we studied whether within-cohort and within-twin-pair differences in XCI are associated with differences in serum concentrations of TPOAb. A total of 318 euthyroid female twin individuals distributed in 159 pairs were investigated. XCI was determined by PCR analysis of a polymorphic CAG repeat in the first exon of the androgen receptor gene. TPOAb concentrations were measured using a solid-phase time-resolved fluoroimmunometric assay. Overall (within cohort), there was a significant association between XCI and serum concentrations of TPOAb; regression coefficient (β)=1.45 (95% confidence interval, 0.52–2.38), P=0.003. The association remained significant in the within-pair analysis; β=1.74 (0.79–2.69), P<0.001. The relationship was nonsignificant within the 82 monozygotic pairs (β=0.57 (−0.78–1.92), P=0.405), whereas the association was significant in the 77 dizygotic pairs (β=2.17 (0.81–3.53), P=0.002). This preliminary finding of a significant association between TPOAb concentrations and XCI within cohort and within dizygotic but not within monozygotic twin pairs may indicate that XCI per se does not have a major role in the pathogenesis of TPOAb. More likely, XCI and TPOAb are influenced by shared genetic determinants.