Premature rupture of the membranes (PROM) is defined as spontaneous rupture of membranes prior to the onset of labor. PROM carries high risks of infection and sepsis and can lead to oligohydramnios. Diagnosis is based on history and testing fluid samples. Management depends on gestational age - if after 36 weeks labor is induced, if earlier conservative management is used to continue the pregnancy while monitoring for infection until the lungs are mature.

1. Premature rupture of the membranes General hospital of Tianjin medical university Zhang Xuhong

2. Definitions PROM is defined as amniorrhexis prior to the onset of labor at any stage of gestation. Amniorrhexis means spontaneous rupture of membranes as opposed to amniotomy. PPROM is used to defined that the patient who are preterm with ruptured membranes, whether or not they have contractions.

3. Etiology and risk factors Vaginal and cervical infections Abnormal membrane physiology Incompetent cervix Nutritional deficiencies

4. Diagnosis It is based on the history of vaginal loss of fluid and confirmation of amniotic fluid in the vaginal A sterile vaginal speculum examination should be performed Before labor, vaginal examination should not be performed Carry out a complete ultrasonic examination

5. Confirmation of the diagnosis can be made by: Testing the fluid with nitrazine paper, which will turn blue in the presence of the alkaline amniotic fluid Placing a sample on a microscopic slide, air drying, and examining for ferning

6. Management General considerations Conservitive expectant management Management of chorioamnionitis Tests of pulmonary maturity

7. General considerations Membranes are a natural barrier to prevent infections PPROM has high risks of infections and sepsus PPROM can lead to oligohydramnios

8. Diagnosis of oligohydramnios Ultrasonic definition has been standadized Criteria include: (1) measure the amniotic fluid present in 4 quadrands by vertical axis (2) AFI: total being called the amniotic fluid index (3) A value of less than 5 cm is considered abnormal

9. Oligohydramnios results in: Fetal crowding with thoracic compression Restriction of fetal breathing Disturbances of pulmonary fluid production and flow Constaints placed on fetal movements in utero can also result in positional skeletal abnomalities, such as talipes equinovarus

10. If PROM occurs at 36 weeks or later, condition of the cervix is favorable,no spontaneous contractions, labor should be induced after 6-12 hours . If PROM occurs prior to 36 weeks’ gestation, we should manage as followings:

11. Laboratory tests Complete blood cells Gram stain and culture of amniotic fluid Pulmonary maturation studies of amniotic fluid

12. Conservative expectant management The goal is to continue the pregnancy until the lung profile is mature Take careful surveillance to diagnose subclinical infection and chorioamnionitis

13. Clinical signs and symptoms of chorioamnionitis Maternal temperature is greater than 100.4 0 F (38 0 C) Fetal tachycardia A tender uterus Uterine irritability on nonstress testing White blood cells elevates Measure the amniotic fluid by ultranography

14. Management of chorioamnionitis Use antibiotics depends on cultures and sensitivity Once antibiotics have been started, labor should be induced Vaginal delivery or cesarean section

15. Tocolytic therapy Use of corticosteriods Labor and delivery They are just the same with preterm labor

16. Tests of pulmonary maturity Lecithin/sphingomyelin(L/S) ratio maturity >2 Lamellar body number density(LBND) maturity>46000  L LBND

17. Surfactant therapy It is effective in animal tests Only on human trials