The association of early pregnancy dyslipidemia with preterm birth in twin pregnancies: a retrospective cohort study oleh Li-Yang Zhou, Zhou Xu, Li Wen, Xin-Zhen Chen, Ying-Ling Yao, Rui-Ling Liu, Yong-Jia Zhang, Zhao-Hui Zhong, Li-Juan Fu, Gong-Li Chen, Yu-Bin Ding