Basic Science of Spontaneous Preterm Labor premature cervical

Basic Science of Spontaneous Preterm Labor

premature cervical dilatation and effacement premature activation of uterine contractions

Four major causes of spontaneous preterm labor include uterine distention maternal–fetal stress • premature cervical changes infection •

The preterm parturition syndrome. Multiple pathologic processes can lead to activation of the common pathway of parturition. In: Creasy, Resnik. Maternal – Fetal Medicine, 2009

Sources for Intrauterine Infection. Transplacental transfer of maternal systemic infection Retrograde flow of infection into the peritoneal cavity via the fallopian tube ascending infection with bacteria from the vagina and cervix

ﻣﺮﺍﺣﻞ ﻋﻔﻮﻧﺖ ﻭﺍژیﻨﻮﺯ ﺑﺎکﺘﺮیﺎﻝ : 1 ﻣﺮﺣﻠﻪ ﻋﻔﻮﻧﺖ ﺩﺳیﺪﻭﺍ : 2 ﻣﺮﺣﻠﻪ ﻋﻔﻮﻧﺖ ﺍﻣﻨیﻮﻥ : 3 ﻣﺮﺣﻠﻪ ﻋﻔﻮﻧﺖ ﺳیﺴﺘﻤیک ﺟﻨیﻦ : 4 ﻣﺮﺣﻠﻪ Ascending intrauterine infections stage I changing flora vagina/cervix, II Microorganism alocated between the amnion and chorion, III intra amniotic infection, IV fetal invation � �

Infections associated with preterm delivery Genital * Bacterial vaginosis (BV) * Group B streptococcus * Chlamydia * Mycoplasmas Intra-uterine * Ascending (from genital tract) * Transplacental (blood-borne) * Transfallopian (intraperitoneal) * Iatrogenic (invasive procedures) Extra-uterine * Pyelonephritis * Malaria * Typhoid fever * Pneumonia * Listeria * Asymptomatic bacteriuria In: Jane Norman. Preterm labor 2005

Relation of Infection and Preterm Birth Genome Uteroplacental Insufficiency Maternal Stress Fetal Stress ↓Progesterone Inhibition Bacteria, Virus, Protozoa Infection: Leukocyte Response ↑TOLL 4 Receptors Cytokine Cascade: ↑TNF, ↑IL 6, ↑ IL 8, etc Genome Decidual Activation Phospholipase A, prostaglandins, lysolethecin, mettaloproteinases, collagenases, elastases. .

Phospholipase A, prostaglandins, lysolethecin, mettaloproteinases, collagenases, elastases. . Preterm Labor Rupture of Membrane Cervical Incompetence PRETERM BIRTH Ref: Edward R. Newton: Clin Perinatol 32 (2005) 571 -600

Stretch Inflammation Abruption Stress Integrins ↑IL-1β ↑TNF-α Thrombin ↑ CRH ↑ Estrogen ↑COX 2 ↓ PGDH ↓ PR-B ↑ MMPs ↑ IL-6 and 8 PTL or PPROM Principal biomechanical mechanisms responsible for chain pathways of preterm parturition COX 2=cyclooxygenase 2, PGDH=prostaglandin dehydrogenase PR-B=Progesteron receptor. B. CRH=corticotropin releasing hormon MMPs=matrix metallo proteinase In: Creasy, Resnik. Maternal – Fetal Medicine, 2009