Premature rupture of membranes and P-PROM

Question 1

What is premature rupture of membranes

Answer 1

Rupture of foetal membranes at least 1 hour prior to the onset of labour at >37 weeks gestation

Question 2

What percentage of pregnancies result in PROM?

Answer 2

10-15%

Question 3

What is pre-term premature rupture of membranes (P-PROM)?

Answer 3

Rupture of foetal membranes occurring at <37 weeks gestation

Question 4

What percentage of pregnancies are complicated by P-PROM?

Answer 4

2%

Question 5

What percentage of preterm deliveries are associated with P-PROM

Answer 5

40%

Question 6

What are foetal membranes composed of?

Answer 6

Chorion and amnion

Strengthened by collagen

Question 7

What happens to the foetal membranes before labour?

Answer 7

Become weaker - apoptosis and collagen breakdown by enzymes

Question 8

Describe the process of PROM and P-PROM

Answer 8

Early activation of normal physiological processes - higher than normal levels of apoptotic markers and MMPs in amniotic fluid

Infection - inflammatory markers

Genetic predisposition

Question 9

List some risk factors for PROM and P-PROM

Answer 9

Smoking (especially <28 weeks gestation) 
Previous PROM/pre-term delivery
Vaginal bleeding during pregnancy 
Lower GU tract infection
Invasive procedures - amniocentesis 
Polyhydrmnios
Multiple pregnancy 
Cervical insufficiency

Question 10

Describe the clinical features from history of PROM and P-PROM

Answer 10

Broken waters - painless popping sensation followed by a gush of watery fluid from the vagina
Can be less specific - gradual leakage of watery fluid from vagina and damp underwear/pad or a change in colour/consistency of vaginal discharge

Question 11

Give the clinical examination findings of PROM/P-PROM

Answer 11

Get woman to lay on examination couch for 30 mins prior to examination - Fluid seen draining from cervix and pooling in posterior vaginal fornix
Asking woman to cough may cause fluid to be expelled

Question 12

Why should digital vaginal examination be avoided till active labour in women with P-PROM/PROM?

Answer 12

Reduces time between rupture of membranes and onset of labour
Increased risk of introducing an ascending intrauterine infection

Question 13

What is the main differential for PROM?

Answer 13

Urinary incontinence - common in later stages of pregnancy

Question 14

What investigations are done for PROM/P-PROM

Answer 14

Maternal history and examination makes diagnosis

High vaginal swab - GBS

Fernig test - placing cervical secretion on glass slife and allowing it to dry - positive ferm patterned crystals

Actim PROM - swab to look for IGFBP-1 (insulin like growth factor binding protein 1) in vaginal samples (concentration in amniotic fluid is 100-1000x greater than maternal serum

Amnisure - placental alpha microglobulin-1 - present in blood, amniotic fluid and vaginal discharge in pregnant women

Question 15

Describe the management of PROM/P-PROM

Answer 15

Amniotic fluid released stimulates the uterus and causes labour within 24-48hrs

If labour doesnt start, important to consider risk vs benefit of expectant management vs IOL

<34 weeks - aim for increased gestation

> 36 weeks - IOL at 24-48hrs as risk of infection

34-36 weeks - IOL and course of steroids

Question 16

List the complications of PROM

Answer 16

Prognosis correlates with gestational age 
Chorioamnionitis 
Oligohydramnios - lung hypoplasia 
Neonatal death
Placental abruption 
Umbilical cord prolapse