Longitudinal change in cerebro-placental ratio (CPR) between 37 and 40 weeks of pregnancy is associated with non-reassuring fetal status and increased risk of cesarean section.

OBJECTIVE: To evaluate in low-risk pregnancies if longitudinal change in cerebro-placental ratio (CPR) between 37 and 40 weeks of pregnancy is associated with cesarean section (CS) for non-reassuring fetal status (NRFS) during labor. METHODS: This is a prospective observational study of women with singleton low-risk pregnancies who underwent an ultrasound scan at 36 + 0 to 37 + 6 and 39 + 0 to 41 + 6 weeks of pregnancy, when the CPR was calculated from the middle cerebral artery (MCA) and umbilical artery (UA) pulsatility indices. Managing professionals were kept blinded to the Doppler results. The association of the longitudinal change between both CPR (z-velocity) to CS for NRFS was evaluated by logistic regression. RESULTS: A total of 401 pregnancies were included. The mean time interval between both CPR evaluations was 21 days (SD 7). A CS for fetal distress was performed in 7% of pregnancies. Independent of the CPR at 37 weeks, the likelihood of CS for fetal distress was significantly decreased by the longitudinal changes from 37 to 40 weeks (OR 0.61, 95%CI 0.4-0.92; p=.018). This association remained significant after further adjustment for potential confounders (nulliparity, maternal weight at booking and estimated fetal weight at 37): (OR 0.64, 95%CI 0.41-0.98; p=.044). CONCLUSIONS: The longitudinal change of CPR between 37 and 40 weeks is associated with the need for CS for NRFS during labor.

TSH-receptor autoantibodies in patients with chronic thyroiditis and hypothyroidism.

OBJECTIVES: The reported prevalence of TSH-receptor (TSHR) autoantibodies (TRAb) in patients with chronic thyroiditis (CT) range from 0 to 48%. The objective was to study the prevalence of TRAb in patients with CT and hypothyroidism and to correlate it with gender, age, thyroid dimensions, TSH levels, and autoimmune diseases. METHODS: The study comprised 245 patients with CT and hypothyroidism (median age 42 years, 193 females, 52 males) and 123 Italian healthy subjects matched for sex and age as controls. TRAb were tested with ELISA using a >2.5 IU/L cut off for positivity. TSHR blocking (TBAb) and TSHR stimulating autoantibodies (TSAb) were measured in 12 TRAb-positive patients using bioassays with Chinese hamster ovary (CHO) cells expressing wild-type or R255D-mutated TSHR. RESULTS: TRAb positivity was found in 32/245 (13.1%) patients and significantly correlated (p<0.05) with TSH levels. TRAb positivity was significantly higher in males vs. females (p=0.034), in females 16-45 years of age vs. >45 years of age (p<0.05) and in patients with reduced vs. normal/increased thyroid dimensions (p<0.05). Linear regression analysis showed a correlation between TRAb concentrations with age (p<0.05) and TRAb concentrations with TSH (p<0.01). In bioassay with TSHR-R255D all 12 patients tested were TBAb-positive while 33% were also TSAb-positive suggesting the presence of a mixture of TRAbs with different biological activities in some patients. CONCLUSIONS: TRAb have been found in patients with CT and hypothyroidism. A mixture of TBAb and TSAb was found in some patients and this may contribute to the pathogenesis of thyroid dysfunction during the course of the disease.

Prescriptive Reference Standards of Third-Trimester Cerebroplacental Ratio and Its Physiological Determinants.

OBJECTIVE: To construct valid reference standards reflecting optimal cerebroplacental ratio and to explore its physiological determinants. METHODS: A cohort of 391 low-risk pregnancies of singleton pregnancies of nonmalformed fetuses without maternal medical conditions and with normal perinatal outcomes was created. Doppler measurements of the middle cerebral artery and umbilical artery were performed at 24-42 weeks. Reference standards were produced, and the influence of physiological determinants was explored by nonparametric quantile regression. The derived standards were validated in a cohort of 200 low-risk pregnancies. RESULTS: Maternal body mass index was significantly associated with the 5th centile of the cerebroplacental ratio. For each additional unit of body mass index, the 5th centile was on average 0.014 lower. The derived 5th, 10th, and 50th centiles selected in the validation cohort were 5, 9.5, and 51% of the measurements. CONCLUSIONS: This study provides methodologically sound prescriptive standards and suggests that maternal body mass index is a determinant of a cutoff commonly used for decision-making.