To examine the influence of prenatal artificial sweetener (AS) consumption on birth outcomes.

Systematic review and meta-analysis.

Online databases (Medline, CINAHL, Embase, Cochrane Library, Scopus, Web of Science, FSTA – the food resource database, and ClinicalTrials.gov) were searched up to 9 April 2020. Studies of all designs (except case studies and reviews) were eligible, which contained information on the relevant population (pregnant women), intervention/exposure (any AS consumption), comparator (no AS consumption) and birth outcomes (preterm delivery, gestational age, birth weight).

From 677 citations, ten cohort studies and one randomised controlled trial (n 138 007 women) were included. ‘Low’ to ‘very low’ certainty evidence revealed that daily consumption of AS was associated with an increased risk of preterm delivery (three studies, n 129 009; risk ratio = 1·18, 95 % CI 1·09, 1·28, I2 = 9 %), a 24 g increase in birth weight (three studies, n 64 417; mean difference (MD): 23·74 g, 95 % CI 0·89, 45·58, I2 = 0 %) and a 0·11 week decrease in gestational age (three studies, n 64 417; MD: –0·11 weeks, 95 % CI –0·19, –0·03, I2 = 0 %).

‘Low’ to ‘very low’ certainty evidence suggests daily AS consumption during pregnancy is associated with an increased risk of preterm delivery, increased birth weight and decreased gestational age. Additional ‘high’-quality research is urgently needed to further assess these relationships.

PROSPERO registration number: CRD42019136728.