조산 및 지연임신

Survival Rate by Birthweight

Probability of Mortality by Gestational Age

Percent Mortality by Birthweight

Causes of Preterm Birth Medical and obstetrical complication Threatened abortion Lifestyle factors Genetic factors Amniotic fluid infection

Causes of Preterm Birth Medical and obstetrical complication Placental hemorrhage Preeclampsia Cervical incompetence Uterine anomaly Hydramnios Trauma

Causes of Preterm Birth Lifestyle factors Alcohol Smoking Cocaine Young maternal age Poverty Short stature Occupational factors

Causes of Preterm Birth Amniotic fluid infection Pathogenesis Bacterial products  monocytes, macrophage  Cytokines  Arachidonic acid  Prostaglandins  Uterine contractions

Causes of Preterm Birth Amniotic fluid infection Diagnosis Amniocentesis Bacterial culture & Gram stain Amniotic fluid WBC Low glucose Cytokines

Identification of Women at Risk Risk scoring system Prior preterm birth Cervical dilatation Signs and symptoms Fetal fibronectin Ambulatory uterine contraction testing Salivary estriol

Identification of Women at Risk Risk Scoring System Scores of 1 through 10 Socioeconomic status Reproductive history Daily habits Current pregnancy complications Scores of 10 or more  high risk

Identification of Women at Risk Prior preterm birth First birth Second birth Next birth preterm(%) Term - 5 Preterm - 15 Term Preterm 24 Preterm Preterm 32

Identification of Women at Risk Cervical dilatation Asymptomatic dilatation USG measurement of cervical length Knowledge of antenatal cervical dilatation Did not affect outcome Prenatal cervical exam Neither beneficial nor harmful

Identification of Women at Risk Signs and Symptoms Painful or painless uterine contractions Pelvic pressure symptoms Menstrual-like cramps Watery or bloody vaginal discharge Pain in the low back  Late warning sign of preterm birth

Identification of Women at Risk Fetal fibronectin Glycoprotein Cervicovaginal secretion Negative results are more meaningful Effective predictor

Identification of Women at Risk Ambulatory uterine contraction testing Ineffective in prevention of preterm birth Salivary estriol Under investigation

Diagnosis of Preterm Labor Herron's criteria Regular uterine contraction after 20 weeks or before 37 weeks 5 to 8 minutes apart or less With one or more of following Progressive change in the cervix Cervical dilatation of 1 cm or more Cervical effacement of 80% or more

Antepartum Management Preterm ruptured membranes Preterm labor with intact membranes

Preterm Ruptured Membranes Natural history 75% already in labor 10% spontaneous labor within 48 hours 7%  delivery delayed 48 hours or more Appeared to benefit from delayed delivery, no neonatal death occurred Time period from rupture to delivery Inversely proportional to gestational age

Preterm Ruptured Membranes Complication Cord prolapse Fetal infection Chorioamnionitis Abruptio placentae

Preterm Ruptured Membranes Expectant management Active interventions did not improve perinatal outcomes May have aggravated infection-related complications Ampicillin plus corticosteroids were beneficial because of less respiratory disease Neonatal survival was not affected by any intervention

Preterm Ruptured Membranes Overt chorioamnionitis Chorioamnionitis가 진단되면 가능한 한 질식분만을 통한 신속한 분만을 시도한다. Fever is the only reliable indicator Infants born to women with chorioamnionitis had increased mortality and morbidity

Preterm Ruptured Membranes Antimicrobial therapy Fewer RDS, necrotising enterocolitis Longer latency Prolonged therapy May cause superinfection Pseudomonas aeruginosa

Preterm labor with intact membranes Same with PROM Antimicrobial therapy 조기진통이 이미 생긴 경우, cytokine cascade를 막기에는 너무 늦다. Glucocorticoid therapy Betamethasone 12 mg IM in two doses 24 hours apart Dexamethasone 5 mg IM every 12 hours for 4 doses, repeated every 7 days

Methods to Inhibit Preterm Labor Bed rest Hydration and sedation Beta-adrenergic receptor agonist Magnesium sulfate Prostaglandin inhibitors Calcium channel-blocking drugs Nitric oxide donor Oxytocin antagonist

Methods to Inhibit Preterm Labor Bed rest Hydration and sedation Beta-adrenergic receptor agonist Ritodrine (Yutopar) Terbutaline

Methods to Inhibit Preterm Labor Beta-adrenergic receptor agonist Ritodrine (Yutopar) Intravenous Side effects Maternal tachycardia, hypotension, apprehension, chest tightness, pulmonary edema Hyperglycemia, hyperinsulinemia, hypokalemia, lactic acidosis

Methods to Inhibit Preterm Labor Beta-adrenergic receptor agonist Terbutaline Not so effective

Methods to Inhibit Preterm Labor Magnesium sulfate 4 g loading dose, 2 g/hr continuous infusion Complications Pulmonary edema Respiratory depression Cardiac arrest Profound muscular paralysis Profound hypotension

Methods to Inhibit Preterm Labor Prostaglandin inhibitors Aspirin, indomethacin, sulindac, naproxen Closure of ductus arteriosus, necrotising enterocolitis, intracranial hemorrhage

Methods to Inhibit Preterm Labor Calcium channel-blocking drugs Nifedipine Decrease vascular resistence Maternal hypotension Decreased uteroplacental perfusion Combination of nifedipine and magnesium for tocolysis is potentially dangerous

Methods to Inhibit Preterm Labor Nitric oxide donor Nitroglycerin Severe hypotension Oxytocin antagonist Atosiban FDA approval  denied

Intrapartum Management Continuous electronic monitoring Prevention of neonatal Group B Streptococcal infection Penicillin G or ampicillin Every 6 hours until delivery Neonatal resuscitation

Postterm Pregnancy Definition ACOG (1997) 42 completed weeks (294 days) or more

Gestational Age at Birth

Perinatal Mortality in Late Pregnancy

Pathophysiology Postmaturity syndrome Unique and characteristic appearance Wrinkled skin Long and thin body Open-eyed, unusually alert, old and worried-looking Long nail Growth - not restricted

Pathophysiology High rate of mortality and morbidity Pregnancy hypertension Prolonged labor with CPD Unexplained anoxia Malformation Primary adrenal hypoplasia Anencephaly

Pathophysiology Fetal distress and oligohydramnios Oligohydramnios  cord compression  fetal distress Fetal release of meconium into already reduced amniotic fluid Thick, viscous meconium  meconium aspiration syndrome

Pathophysiology Increased perinatal risk Meconium stain Labor induction Cesarean delivery Macrosomia Shoulder dystocia Meconium aspiration

Postmaturity Syndrome

Intrapartum management Continuous electronic monitoring Meconium passage Suction the pharynx as soon as the head is delivered Trachea should be aspirated as soon as possible after delivery Consider cesarean section when delivery is remote