The incidence rate of each APO in the study population and its corresponding rate in the elevated and normal MS-AFP groups were 5.44% (11.67 vs. 4.96%, P = 0.000) for preterm birth, 0.96% (1.25 vs. 0.94%, P = 0.500) for stillbirth, 2.44% (6.25 vs. 2.14%, P = 0.001) for preeclampsia, and 10.89% (17.92 vs. 10.34%, P = 0.001) for SGA. Here, AFP is linked to preeclampsia.