Intervention not reported
The intervention leads to lower preterm birth less than 34 weeks' gestation (high certainty).
- RR 0.78 [0.62, 0.99]3 studies · 1596 participantsHigh
The intervention leads to lower preterm birth less than 34 weeks' gestation (high certainty).
It is very uncertain whether the intervention changes preterm birth less than 37 weeks' gestation (very low certainty).
It is very uncertain whether SOF Immunological sealant changes preterm birth less than 37 weeks' gestation compared with standard care (very low certainty).
Vitamin D + calcium supplementation may leads to higher preterm birth (less than 37 weeks' gestation) compared with placebo or no intervention (low certainty).
Vitamin D + calcium + other vitamins and minerals showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with calcium + other vitamins and minerals (but no vitamin D) (low certainty).
Vitamin D supplementation showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with placebo or no intervention (low certainty).
Any vitamin E supplementation showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with placebo, no placebo or other supplements (high certainty).
Oral betamimetic showed no clear difference in preterm birth (less than 37 weeks' gestation) compared with placebo (low certainty).
Oral betamimetic showed no clear difference in very preterm birth (less than 34 weeks' gestation) compared with placebo (low certainty).
(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).
The review found no eligible studies for this question.
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).