Infection & Preterm Birth

Objectives Understand magnitude of problem of PTB. Gain understanding of role of infection in spontaneous PTB. Overview of clinical decision making and “art” of medicine regarding PTB.

Rate of PTB ~ 10% and increasing Primary cause of neonatal morbidity and mortality

Economic Impact of PTB

Risk Factors for Preterm Delivery Previous obstetric history Race/ethnicity Multiple gestation Incompetent cervix Congenital Anomalies

Risk Factors for Preterm Delivery Substance abuse Pre-Pregnancy Weight Stress Maternal Age INFECTION

Infection and PTB 40% of PTB due to infection ↓ Gestational Age Infection Only pathologic process with firm causal link established Fetal infection & inflammation  Cerebral palsy & chronic lung disease

Infection & PTB: Pathophysiology Change in flora Localized Inflammatory Reaction Invasion of Amniotic Fluid Fetal Invasion

Case Study 1 24 yo at 23 weeks EGA with gush of fluid Bacterial vaginosis diagnosed on vaginal exam Admitted, antibiotics started, counseled Family opts for expectant management

Case Study 1 Develops fever and uterine tenderness Contractions increased Vaginal delivery of 800 gm baby boy Severe respiratory distress, multi-organ system failure.

Case Study 2 34 yo at 35 weeks with contractions and cervical dilation. Group B Strep isolated from vagina at last prenatal visit.

Case Study 2 Amniocentesis showed mature fetal lungs Antibiotics continued Vaginal delivery Baby weighted 5#5oz; stayed in nursery for 5 days then discharged to home. No long term sequelae.

Case Study 3 30 yo at 26 weeks presenting with flu-like illness, rash, vaginal discharge and uterine cramping. Primary Genital Herpes

Case Study 3 Intravenous anti-viral medication Tocolytics to relax uterus Contractions continued and membranes ruptured Cesarean delivery of 2.5# infant

Case Study 3 Support in NICU IV antivirals Spinal tap Disseminated HSV