<p>The placenta is the most critical organ during pregnancy and its developmental status directly impacts fetal health. Placental dysfunction is associated with various pregnancy complications, including preterm birth, fetal growth restriction, and premature rupture of membranes (PROM). This study aimed to elucidate the expression changes of Bax and Bcl-2 and their association with pregnancy-related complications, providing new insights into placental dysfunction during pregnancy and offering a theoretical foundation for clinical diagnosis and prevention. The placental samples from 118 late pregnant women were retrospectively analyzed. They were assigned into pre-term, term, post-term, PROM, and non-PROM groups based on gestational age and the occurrence of PROM. Immunohistochemistry (IHC) staining was performed to gauge the Bax and Bcl-2 expressions in placenta. Receiver operating characteristic (ROC) curve was subsequently conducted to assess their associated with efficacy for PROM. The weight and volume of placentas in the pre-term group were sharply smaller to those in the term and post-term groups, with no apparent fibrosis or calcification observed. The term and post-term groups exhibited marked elevated Bax expression in the parturient group in contrast to the non-parturient group (<i>P</i> &lt; 0.05), while there existed no substantial significance in Bcl-2 expression. The area under the curve (AUC) for Bax and Bcl-2 was 0.975 and 0.596, respectively, with a combined associated with value of 0.978, higher to single predictions. Bax and Bcl-2 expressions in late pregnancy placentas were associated with the onset of parturient status and PROM and their combined prediction exhibited accurate PROM predicted. These findings offered a new perspective for understanding the physiological and pathological changes of the placenta during pregnancy.</p>