|Study Authors, year||Study Sample characteristics;||findings||outcomes||Critical review|
|Brown et al. 2014|
|−677 mothers of ASD were matched with 677 control.|
-Covariates included maternal age, paternal age, number of previous births, maternal socioeconomic status, pre-term birth, low birthweight, maternal/ parental history of psychiatric disorders, and gestational week of the blood draw
|80% increase in risk of ASD with elevated mCRP, in the highest decile (> 9.55 mg/dl), compared to the lowest decile (0.10–0.57 mg/dl) (OR = 1.80, 95% CI = 1.09–2.97, p = .02)|
greater association for females, but no interaction between mCRP and gender or mental retardation.
|significant association between increasing maternal CRP (as continuous variable) and risk of ASD (OR = 1.12, 95% CI = 1.02–1.24, p = 0.02||-Retrospective Case control study provides only weak evidence for association.|
− 455 cases were excluded from sample of 1132).
-Many important confounding factors were not recorded
i.e. history of infection, or inflammatory disorder, genetic analysis, immunoglobulin levels, psychopathology in pregnancy, or ethnicity.
|Koks et al. 2016|
|-mCRP levels in early pregnancy and Social Responsiveness Scale (SRS) scores in children at the age of 6 years were analyzed for 4165 mother-child pairs.||mCRP levels and SRS scores were found to be associated but sequential modelling with confounding factors made the association disappear.||no association between elevated levels of mCRP during early pregnancy and parent-reported autistic traits in children at the age of 6 years.||-Retrospective Case and control study provide|
− 1042 mother-child pairs data excluded have younger mothers with different lifestyle i.e. more smoking.
|-population-based nested case–control study with 500 children with ASD, 235 with developmental delay (DD) and 580 general population (GP)|
− 2 phase study.
|-First sample set. Median mCRP levels were lower in the mothers of children with ASD (1.28 mg/dl, interquartile range = 0.54–3.06)|
compared with the mothers of GP controls (2.43 mg/dl, interquartile range = 0.61–3.82
-Median CRP levels were significantly lower in the mothers of children with ASD (1.94 mg/dl, interquartile range = 1.04–3.90) compared with the mothers of GP controls (2.40 mg/dl, interquartile range = 1.32–4.48
|mCRP levels in mid-pregnancy were lower in mothers of ASD compared with controls. The maternal CRP levels in the upper third and fourth quartiles were associated with a 45 and 44% decreased risk of ASD, respectively (negative association)||-Retrospective case control study.|
-Study has 2 phases with different sample size and different technique for mCRP measurement.