Table 2.

Participants.

No	Study	Participants
1	Crowther 2003 [7]	1062 women with fetuses < 30 weeks’ gestation and 1255 born infants.
2	Marret 2006 [8]	564 women with fetuses of gestational age < 33 weeks and 688 born infants.
3	Mittrendorf 2002 [24]	55 women with preterm labor at 25–33 weeks’ gestation and 59 born infants.
4	Rouse 2008 [10]	2241 women at imminent risk for delivery between 24 and 31 weeks of gestation and 2444 born infants.
5	Doyle 2014 [18]	669 infants out of 1255 infants who participated in Crowther 2003.
6	Chollat 2014 [19]	431 infants out of 688 infants who participated in Marret 2006.
7	Paradidis 2012 [20]	114 women out of 1062 women who participated in Crowther 2003 and 132 born infants.
8	Drassinower 2015 [21]	1047 singleton women out of 2241 women who participated in Rouse 2008 and 1047 born infants.
9	Colon 2016 [22]	30 women between 24 and 34 weeks of gestation presenting labor and delivery diagnosed with non-severe placental abruption and 31 born infants.
10	Wolf 2020 [23]	560 pregnant women at risk for preterm delivery before 32 weeks of gestation and 680 born infants.