上海交通大学医学院：《妇产科学》（双语） 23 Preterm labor

Preterm Labor Lin Qi de

Preterm Labor Lin Qi de

Definition Preterm Labor Labor occurring prior to the completion of 37 weeks' of gestation (228 weeks), or 196-258 days from the last menstrual period (LMP)

Definition Preterm Labor : Labor occurring prior to the completion of 37 weeks’ of gestation(≥28 weeks’), or 196-258 days from the last menstrual period (LMP)

Etiology o Maternal factors (1) Clinical complication: cardiovascular, liver renal dieases pih severe anemia et al (2) Uterine distortion: Leiomyoma, uterus didelphys, uterus septus, Incompetent cervix and other abnomalities

Etiology Maternal factors: (1) Clinical complication:cardiovascular, liver,renal dieases,PIH , severe anemia et al (2) Uterine distortion: Leiomyoma,uterus didelphys , uterus septus, Incompetent cervix and other abnomalities

o Fetal and placental factors (1) Hydramnios (2) Multiple pregnancy (3)PROM (4)Placental abruption ()Placenta praevia (6 Urinary, intra-amniotics infection

Fetal and placental factors: (1) Hydramnios (2) Multiple pregnancy (3) PROM (4) Placental abruption (5) Placenta praevia (6) Urinary , intra- amniotics infection

Symptoms and signs e Uterine contraction, 〔 irregulation→ regulation) oIncrease or change in vaginal discharge (mucous, watery, light bloody discharge) Taking up“ of the cervix o Progressive dilatation of the os

Symptoms and Signs Uterine contraction, (irregulation regulation) Increase or change in vaginal discharge (mucous,watery,light bloody discharge) “Taking up “ of the cervix Progressive dilatation of the os

Preventation (1)Antenatal care (2)Treat clinical complication (oPeration for the os

Preventation (1) Antenatal care (2) Treat clinical complication (3) Operation for the os

Management of PTL The purpose of treating PTL: delay delivery, if possible, until fetal maturity ◆ fetal alive ● no fetal distress e no PROM (1 Rest in the bed, lie on left side (2)Prevent RDS: dexamethasone 5mg im 3days to enhance pulmonary maturity

Management of PTL The purpose of treating PTL : delay delivery, if possible, until fetal maturity fetal alive no fetal distress no PROM (1) Rest in the bed, lie on left side (2) Prevent RDS: dexamethasone 5mg im 3days to enhance pulmonary maturity

(3 Tocolysis therapy B-adrenergic agents: increase CAMP in cell which decreases free calciun(B2- receptors predominate in the uterus lung and blood vessels) Prostaglandin synthetase inhibitors decrease prostaglandin(PG) production o Calciun channel blockers prevent calcium entry into muscle cells

(3) Tocolysis therapy : -adrenergic agents: increase cAMP in cell which decreases free calciun(2- receptors predominate in the uterus ,lung and blood vessels) Prostaglandin synthetase inhibitors: decrease prostaglandin(PG) production Calciun channel blockers: prevent calcium entry into muscle cells

Q Magnesium sulfate: competes with calcium for entry in to cells 25%MySO4+ 5%GS 500ml 80-100ml h(first hour) pay attention to >The respiratory: more than 16/ min )The knee reflection must be exist >The urine volume must be more than 600m/24h(25m/h) >Calcium resistance must be prepared

Magnesium sulfate:competes with calcium for entry in to cells 25%MySO4 + 5%GS 500ml 80-100ml/h(first hour) pay attention to : ➢The respiratory: more than 16 /min ➢The knee reflection must be exist ➢The urine volume must be more than 600ml/24h (25ml/h) ➢Calcium resistance must be prepared