Developmental outcomes in children born to women with possible subclinical rubella exposures during pregnancy.

This study investigated outcomes of children born to women who seroconverted to rubella immune during pregnancy. In a prior 2012-2013 study of 296 women who were rubella nonimmune, 26 (8.8%) seroconverted to rubella immune during pregnancy. These same women and their now 8-9 years-old children were queried as to the children's developmental health. After removing exclusions and those lost to follow-up, the total response rate was 115/204 (56.4%). Three sets of twins in the nonimmune group increased the total to 118. The seroconversion group had more autism (12.5% vs. 3.9%, p = 0.19), ADHD (37.5% vs. 18.6%, p = 0.10), and any developmental disability (43.8% vs. 31.4%, p = 0.39) but none showed a statistical difference between the two groups. Compared to Autism and Developmental Disabilities Monitoring data, the seroconversion group had a greater prevalence of autism (odds ratio [OR] 6.07, p = 0.051, nonsignificant); and to data derived from the National Health Interview Survey, a nonsignificant higher odds of autism (OR 5.57, p = 0.060), higher odds of ADHD (OR 5.65, p = 0.0027) and of any developmental disability (OR 3.59, p = 0.014). The nonimmune group also demonstrated a statistically significant increase for both ADHD and any developmental disability, but not for autism.

Vertical Transmission and Discordance of Cytomegalovirus in Twin Pregnancies.

Objective: The objectives are to estimate the vertical transmission rate in twins relative to singleton pregnancies, to evaluate whether discordance within twin pairs is rare, and to characterize concordance within monozygotic and dizygotic twin pairs in relation to hereditability. Methods: We first sought to estimate the vertical transmission rate of congenital CMV infection in twins by gathering cohort-based studies of congenital CMV in which vertical transmission in both singleton and twin pregnancies was reported. This also allowed us to compare singleton and twin infection rates. From the above studies and other large cohorts of congenitally infected infants, the percentage of discordantly infected twin pairs determined whether this is a rare phenomenon. Theorizing discordance is not rare, we then analyzed data from cases with twin outcomes for congenital CMV infection, according to whether the twins were monozygotic or dizygotic, and calculated their corresponding concordance rates to estimate the broad-sense heritability. Lastly, we described other factors that might affect vertical transmission. Results: From five articles following at-risk pregnancies, the rate of vertical transmission in twin pregnancies is 58.7% (95% CI 43.3-72.3%) whereas in singleton pregnancies it is 31.4% (95% CI: 29.0-34.0%) p = 0.0002. Of ten studies of larger cohorts of infants with congenital CMV infection, 21 of 42 twin pairs with at least one twin infected were discordant for congenital CMV (50.0%, 95% CI: 34.4-65.6%) indicating discordance of congenital CMV infection in twin pairs is not rare. Of 28 studies covering 37 twin pairs where at least one twin had congenital CMV, and zygosity was known, eleven of thirteen monozygotic twin pairs (84.6%; 95% CI: 53.7-97.3%) were concordant for CMV infection, and nine of twenty-four dizygotic twin pairs (37.5%; 95% CI: 19.6-59.2%) were concordant for infection giving an estimated hereditability of 94.2%. Within these 37 twin pairs, factors such as primary or recurrent maternal infection, prematurity, growth discordance, and sex are described; however, in many of these cases these factors are unknown. Conclusion: The rate of vertical transmission of congenital CMV is higher for twins than singletons. Discordance of congenital CMV in twins is not rare and suggests a possible genetic susceptibility to congenital CMV.

Does Rubella Cause Autism: A 2015 Reappraisal?

In the 1970s, Stella Chess found a high prevalence of autism in children with congenital rubella syndrome (CRS), 200 times that of the general population at the time. Many researchers quote this fact to add proof to the current theory that maternal infection with immune system activation in pregnancy leads to autism in the offspring. This rubella and autism association is presented with the notion that rubella has been eliminated in today's world. CRS cases are no longer typically seen; yet, autistic children often share findings of CRS including deafness, congenital heart defects, and to a lesser extent visual changes. Autistic children commonly have hyperactivity and spasticity, as do CRS children. Both autistic and CRS individuals may develop type 1 diabetes as young adults. Neuropathology of CRS infants may reveal cerebral vasculitis with narrowed lumens and cerebral necrosis. Neuroradiological findings of children with CRS show calcifications, periventricular leukomalacia, and dilated perivascular spaces. Neuroradiology of autism has also demonstrated hyperintensities, leukomalacia, and prominent perivascular spaces. PET studies of autistic individuals exhibit decreased perfusion to areas of the brain similarly affected by rubella. In both autism and CRS, certain changes in the brain have implicated the immune system. Several children with autism lack antibodies to rubella, as do children with CRS. These numerous similarities increase the probability of an association between rubella virus and autism. Rubella and autism cross many ethnicities in many countries. Contrary to current belief, rubella has not been eradicated and globally affects up to 5% of pregnant women. Susceptibility continues as vaccines are not given worldwide and are not fully protective. Rubella might still cause autism, even in vaccinated populations.

Rubella monitoring in pregnancy as a means for evaluating a possible reemergence of rubella.

OBJECTIVE: Although it is commonly accepted that rubella is well-controlled, a recent reemergence of both pertussis and measles might also predict a reemergence of rubella. This study was designed to estimate the current incidence of rubella exposure in pregnancy. STUDY DESIGN: This was a prospective, descriptive study, conducted in Houston, TX, at The Woman's Hospital of Texas. Women are typically screened for rubella immunity at the beginning of pregnancy. Rubella nonimmunity is defined as a titer less than 10 IU/mL in the US. Women who were non-immune early in pregnancy (<20 weeks) were recruited for this study and asked to be tested again for rubella immunity at the time of delivery. RESULTS: Of 298 women who were rubella nonimmune (IgG <10 IU/mL) early in pregnancy, 19 converted to immune status (IgG >40 IU/mL, defined as at least a 4-fold increase) at time of delivery, a rate of 6.38% (4.12% to 9.75%; 95% Wilson-Score confidence interval). For the 19 patients who converted to immune status at time of delivery, 8 patients had levels of 40-150 IU/mL, 6 patients had levels of 151-300 IU/mL, 2 patients had levels of 301-500 IU/mL, and 3 patients had levels >500 IU/mL. CONCLUSION: Pregnancy is a critical time to evaluate rubella exposure. This study estimated the current incidence of rubella exposure in pregnancy to be 6.38%.