(Infant outcomes) Any supplements containing iron and folic acid showed no clear difference in preterm birth (less than 37 weeks of gestation) (ALL) compared with same supplements without iron nor folic acid (no iron nor folic acid… (low certainty).
(Infant outcomes) Any supplements containing iron showed no clear difference in preterm birth (less than 37 weeks of gestation) (ALL) compared with same supplements without iron or no treatment/placebo (no iron or… (moderate certainty).
Setting of BP measurement: self‐measurement showed no clear difference in preterm birth (birth before 34 completed weeks' gestation) compared with conventional clinic measurement (low certainty).
The review found no eligible studies for this question.
Test of placental function showed no clear difference in preterm birth (before 37 weeks' gestation) reported gestation at birth compared with standard care (low certainty).
Group antenatal care showed no clear difference in preterm birth (gestational age at time of birth less than 37 weeks'… compared with individual antenatal care (adjusted data) (moderate certainty).
The intervention showed no clear difference in preterm birth (< 37 weeks gestation) (Any psychosocial intervention… (moderate certainty).
The intervention showed no clear difference in preterm birth < 37 weeks Gestational age based on the date of last… (moderate certainty).
The intervention showed no clear difference in very preterm birth (less than 34 weeks) ‐ assuming complete… (low certainty).
The intervention showed no clear difference in very preterm birth (less than 34 weeks) ‐ assuming complete… (low certainty).
The intervention showed no clear difference in preterm birth < 37 weeks Gestational age was based on date of last… (moderate certainty).
Multivitamins showed no clear difference in preterm birth < 37 weeks Gestational age was determined using date… compared with no multivitamins (moderate certainty).