Koullali B, van Zijl MD, Kazemier BM, et al. - Researchers sought to determine if and how parity influence the risk of spontaneous preterm birth. In this retrospective study, they assessed live singleton births (≥ 22 weeks) of women with a first, second, third, fourth or fifth pregnancy in The Netherlands from 2010 through 2014. Assessment of 802,119 pregnancies was done; these comprised 30,237 pregnancies that ended spontaneously < 37 weeks. Per data gained, there was an independent correlation between nulliparity and spontaneous preterm birth < 37, < 32 and < 28 weeks. Furthermore, women in their fifth pregnancy were noted to be at an increased risk for spontaneous preterm birth, with highest risk for preterm birth at early gestational age.