正常分娩讲课教案.ppt

正常分娩(英文) Definitions Labor is the process by which contractions of the gravid uterus expel the fetus and the other products of conception after 28 weeks from the last menstrual period Term Delivery A term delivery occurs between 37 and 42 weeks from the last menstrual period. Premature labor. Preterm labor is that occurring before 37 weeks of gestational age. Postdate pregnancy Postdate pregnancy occurs after 42 weeks The etiology of labor Not sure 1, Cervix ripend and lower uterine segment development theory; 2, Endocrine regulating theory 3、 Mechanical theory 4、 Neurohumor theory 5、 Immunologic theory Maturation of fetus and change of uterus function is necessary. Four Determinate Factors of labor The progress and final outcome of labor are influenced by 4 factors (I)the powers (2)the passage ()the passenger (4)the psyche The expulsive forces(The powers) The power that expulse the fetus and the other products of conception is called the expulsive forces, which include ♀ uterine contraction 9 intra-abdominal pressure 9 levator ani muscles contractions 6 Uterine contractions Have three unique characteristics: *Rhythm: increase in frequency and duration, is the important marker of in laboro * Symmetry and polarity ★ Retraction Rhythm Increase in frequency and duration Periods of relaxation between contractions are essential to the welfare of the fetus Characteristic of normal uterine action intramuscular pressure (mmHg) Intersity of the contraction T ⊥Pain x Symmetry and Polarity The intensity of the upper segment of the uterus is the most strong 子宫收缩力的对称性