OB LE 7 POWERPOINT HANDOUT FORM.pdf

OB LE#7: PREMATURE RUPTURE OF MEMBRANE, GENETICS PRELABOR RUPTURE OF MEMBRANES MEMBRANES

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Decidual activation - mediated by the fetal-decidual paracrine system and through localized decreases in progesterone concentration. Intrauterine bleeding or occult intrauterine infection. 

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The  progesterone withdrawal theory stems from studies in sheep. As parturition nears, the fetal-adrenal axis becomes more sensitive to adrenocorticotropic hormone, increasing the secretion of cortisol (see Chap. 6, p. 157). Fetal cortisol stimulates placental 17- β-hydroxylase  β-hydroxylase activity, which decreases progesterone secretion and increases estrogen production. The reversal in the estrogen/progesterone ratio results in increased prostaglandin formation, which initiates a cascade that culminates in labor. In human beings, serum progesterone concentrations do not fall as labor approaches. Even so, because progesterone antagonists such as RU486 initiate preterm labor and progestational agents prevent  preterm labor, decreased decreased local progesterone progesterone concentrations may may play a role. Because intravenous oxytocin  oxytocin   increases the frequency and intensity of uterine contractions, oxytocin is assumed to play a part in labor initiation. But serum concentrations of oxytocin do not rise before labor, and the clearance of oxytocin remains constant. Accordingly, oxytocin is an unlikely i nitiator.  An important pathway leading to labor initiation implicates inflammatory decidual activation. activation. At term, such activation seems to be mediated at least in part by the fetal-decidual paracrine system and perhaps through localized decreases in  progesterone concentration. concentration. In many cases cases of early preterm labor, however, however, decidual activation seems to arise in the con- text of intrauterine bleeding or occult intrauterine infection.

Dr. Maria Anna Luisa L. Festin-Dalawangbayan, Festin-Dalawangbayan, MD, FPOGS, FPSUOG

Objectives:  To be able to define Preterm Labor and Premature Rupture of Membranes  To be able to identify the risk factors in PROM  To be able to diagnose PROM  To be able to identify the risks o f PROM to the mother and baby To be able to review the management of patients with PROM  Definition of Terms  PRETERM LABOR  regular contractions before 37 weeks AOG associated w ith cervical change  THREATENED PRETERM LABOR criteria not meant but warrants active intervention  PRETERM BIRTH   birth before 37 week AOG or 259 days from the first day of last n ormal LMP  EXTREMELY PRETERM PRETERM::