PROM And P-PROM

Question 1

What is premature rupture of membranes?

Answer 1

The rupture of the foetal membranes at least 1 hour prior to the onset of labour at >/= 37 weeks gestation.
This occurs in 10-15% of term pregnancies and is associated with minimal risk to the mother and foetus due to the advanced gestation.

Question 2

What is pre-term premature rupture of membranes?

Answer 2

The rupture of foetal membranes occurring at under 37 weeks gestation.
It complicates around 2% of pregnancies and has higher rates of maternal and foetal complications.
It is associated with 40% of preterm deliveries.

Question 3

Describe the normal physiological process which results in rupture of foetal membranes.

Answer 3

The foetal membranes consist of the chorion and the amnion. They are strengthened by collagen and become weaker at term in preparation for labour.
The weakening is caused by apoptosis and collagen breakdown by matrix metalloproteinases.

Question 4

What factors can lead to early weakening and rupture of foetal membranes?

Answer 4

Early activation of normal physiological processes (higher than normal apoptotic markers and MMPs in the amniotic fluid).
Infection (inflammatory markers like cytokines contribute to weakening of foetal membranes. Approx. 1/3 of women with P-PROm have positive amniotic fluid cultures).
Genetic predisposition.

Question 5

What are the risk factors for P-PROM and PROM?

Answer 5

Smoking 
Previous PROM/pre-term delivery
Vaginal bleeding during pregnancy
Lower genital tract infection
Invasive procedures like amniocentesis
Polyhydraminos
Multiple pregnancy
Cervical insufficiency

Question 6

What are the clinical features of PROM?

Answer 6

Painless popping sensation followed by a gush of watery fluid leaking from the vagina.
Can also be gradual leakage of fluid and dap underwear/pad.
Change in colour/consistency of vaginal discharge.
Lack of normal vaginal discharge (washed clean).

Question 7

What would you do to examine a woman with suspected PROM?

Answer 7

Ask the woman to cough and observe amniotic fluid being expelled.
If this does not occur, conduct a speculum examination on which you can see fluid draining from the cervix and pooling in the posterior vaginal fornix. The patient should first be laid down on the examination couch for 30 mins to allow pooling of the fluid.

Question 8

In suspected PROM/P-PROM, why should you avoid digital vaginal examination unless actively in labour?

Answer 8

Digital examination can reduce the time between rupture of membranes and the onset of labour.
There is also an increased risk of introducing ascending intrauterine infection.

Question 9

What are the differentials of PROM and P-PROM?

Answer 9

Urinary incontinence (common in later stages of pregnancy)
Normal vaginal secretions of pregnancy
Increased sweat/moisture around the perineum
Increased cervical discharge e.g. with infection
Vesicovaginal fistula
Loss of mucous plug

Question 10

How is the diagnosis of PROM/P-PROM made?

Answer 10

Maternal history

Positive examination

Question 11

What investigations may be performed or suspected PROM/P-PROM?

Answer 11

High vaginal swab in all cases (may grow GBS which indicates antibiotics in labour/give potential cause e.g. bacteria vaginosis)
USS (not routinely used, but when Dx unclear) - shows reduced levels of amniotic fluid in utero
Ferning test (cervical secretion forms fern-patterned crystals)
Actin-PROM - vaginal swab for IGFBP-1 which is in higher concentrations in amniotic fluid
Amnisure- PAMG-1 - high concentrations in amniotic fluid
Nitrazine testing - measures vaginal pH (amniotic fluid has a high pH) - no longer routinely used - high false positives (17%) due to ontamination with urine, blood or semen

Question 12

Why does labour usually begin 24-48 hours after rupture of membranes?

Answer 12

Amniotic fluid stimulates the uterus.

There is very little that can be done to stop this process.

Question 13

Describe the management aims for managing rupture of membranes at under 34 weeks.

Answer 13

Aim for increased gestation.

Question 14

Describe the management aims for managing rupture of membranes at over 36 weeks.

Answer 14

If labour has not started after 24-48 hours, consider induction of labour.
This is because the risk of infection outweighs the benefit of the foetus remaining in utero.

Question 15

Describe the management aims for managing rupture of membranes at 34-36 weeks.

Answer 15

Induction of labour with a course of steroids.

Question 16

What is the management of P-PROM/PROM at over 36 weeks?

Answer 16

Monitor signs of chorioamnionitis.
Clindamycin/penicillin during labour if GBS isolated.
Watch and wait for 24 hours (60% go into labour)/consider induction of labour.
Greater than 24 hours - IOL and delivery recommended.

Question 17

What is the management of P-PROM/PROM at 34-36 weeks?

Answer 17

Monitor for signs of chorioamnionitis
Advise to avoid sexual intercourse as can increase the risk of ascending infection.
Prophylactic erythromycin 250mg QDS for 10 days
Clindamycin/penicillin during labour if GBS isolated.
Corticosteroids if between 34 and 34+6 weeks gestation.
IOL and delivery recommended.

Question 18

What is the management of P-PROM/PROM at 24-33 weeks?

Answer 18

Monitor for signs of chorioamnionitis.
Avoid sexual intercourse due to risk of ascending infection.
Corticosteroids.
Expectant management until 34 weeks.

Question 19

What are the complications of PROM?

Answer 19

Risk of complications correlates with gestational age as there is a greater latency period.

Chorioamnionitis (risk increases the longer the membranes remain ruptured and baby undelivered).
Olighydramnios (particularly significant if under 24 weeks as increases risk of lung hypoplasia)
Neonatal death due to complications associated with prematurity, sepsis and pulmonary hypoplasia
Placental abruption
Umbilical cord prolapse