PIGF and preterm premature rupture of the membranes: Currently, AFP is tested both independently and in combination with other biochemical markers (PAPPA-A, beta-HCG, estriol, inhibin-A, PIGF, and sFIt-1) in early diagnoses of preeclampsia, small for gestational age (SGA), preterm birth (PTB), and premature prelabor rapture of membranes (PPROM), as well as placenta accreta spectrum (PAS) (Figure 4).