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Aim: This study dynamically designed, evaluated, and implemented the components of an Australian newborn bloodspot screening (NBS) pilot programme for spinal muscular atrophy (SMA). Method: We used an implementation‐effectiveness study design and continuous interdisciplinary review to measure SMA NBS test protocol performance, identify and overcome laboratory and clinical barriers to implementation, and describe progress during the 2‐year pilot study. Results: The NBS programme screened 252 081 newborn infants from 1st August 2018 to 31st January 2021. Using an NBS pilot test protocol, 21 infants were diagnostically confirmed with SMA. The NBS pilot test protocol had a sensitivity of 100%, specificity greater than 99.9%, false‐positive rate less than 0.001%, a false‐negative rate of 0%, and positive predictive value of 95.5%. A severe phenotype was predicted on the basis of two copies of SMN2 in 57.2% of newborn infants screening positive for SMA. Clinical signs consistent with SMA were evident in 6 out of 21 screen‐positive newborn infants within the first 4 weeks of life. A multidisciplinary team establishing strong partnerships across clinical and laboratory staff was key to implementation. Interpretation: This pilot programme suggests that NBS is essential for early identification of newborn infants at risk of SMA and can be effectively translated into clinical practice. This original article is commented by Mueller‐Felber on page 535 of this issue. [ABSTRACT FROM AUTHOR]

Tandem mass spectrometry can be used to identify newborn babies who may have a metabolic disease. This technique measures the amount of amino acids and other substances to detect any unusual amounts that could be caused by a metabolic disease. However, many of these babies would have no symptoms and it is not clear whether they would ever develop symptoms.

Objective: To investigate effects of maternal diabetes and metformin treatment on metabolic newborn screening (NBS) results of infants born to mothers with hyperglycemia during pregnancy.Research Design and Methods: Retrospective case-control study. NBS results of infants born to mothers treated with metformin for hyperglycemia during pregnancy were compared with diet-treated subjects with diabetes and matched normal control subjects.Exclusions: maternal type 1 diabetes, major fetal anomalies, and incomplete infant data. Inclusions: maternal hyperglycemia in pregnancy treated with diet alone or diet plus metformin. Results from the New South Wales Newborn Screening Program (dried infant blood spot sample, 24-72 h after birth) for 25 routinely studied analytes were measured using mass spectrometry. Data from metformin-exposed and control infants were compared using nonparametric methods and multiples of the median for each analyte.Results: A total of 574 case subjects were compared with 952 diet-treated case subjects with diabetes and 979 control subjects. Metformin-exposed infants had shorter gestational age (266 ± 7 vs. 272 ± 10 vs. 274 ± 9 days) (P < 0.001) and lower birth weights (3.28 ± 0.51 vs. 3.29 ± 0.49 vs. 3.33 ± 0.43 kg) (P = 0.008). Short-, medium-, and one long-chain acylcarntine (tetradecanoylcarnitine [C14]) concentrations were higher in the metformin-exposed group compared with normal control subjects. Comparison with diet-treated control subjects with diabetes (to eliminate confounding by hyperglycemia) continued to show raised butyrylcarnitine (C4), isovalerylcarnitine (C5), and glutarylcarnitine (C5D) in the metformin-exposed group. There was no evidence of vitamin B12 deficiency (low methionine and elevated propionylcarnitine [C3]) in metformin-exposed infants. All results were within normal population limits.Conclusions: We have identified subtle (nonpathological) changes in neonatal metabolism that represent a signature effect of fetal metformin exposure. [ABSTRACT FROM AUTHOR]