PPROM AND TERM PROM Flashcards
Full meaning of PROM
- Prelabour rupture of membranes
- Premature rupture of membranes
Another term for PROM
Prelabour amniorrhexis
T/F: Premature rupture of membranes is rupture of membranes before the onset of labor, irrespective of gestational age
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3 types of PROM
- Preterm PROM = before 37wks
- Term PROM = 37 or more wks
- Previable PROM = Before 28 wks
What is latency period in PROM
Period from ROM to onset of contractions/labour
T/F: If a woman has ROM and goes into labour within 1 to 2 hours, it is not PROM
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Minimum latency period of PROM
1 - 2 hours
Median latency after PPROM
7 days
What is prolonged ROM
Any ROM that persists for more than 24 hours and prior to the onset of labor
Incidence of PROM in all pregnancies
12%
Incidence of PROM in term pregnancies
8%
Incidence of PROM in preterm deliveries
30%
3 pathways to preterm birth
- Spontaneous preterm labor (40%)
- Premature rupture of membranes (35%)
- Medical intervention (25%)
T/F: Multifetal pregnancies comprise 3% percent of all live births
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% of preterm births resulting from spontaneous preterm labour
40% (40 - 50%)
% of preterm births resulting from premature rupture of membranes
35% (25 - 40%)
% of preterm births resulting from medical intervention
25% (20 - 35%)
8 sequelae of PROM
Preterm delivery
Chorioamnionitis (13-60%; 53.4% Eleje et al)
Non-reassuring fetal status (8 %)
Cord Prolapsed
Abruptio placenta (4%)
Pulmonary hypoplasia
Cesarean
IUFD (1%; 8.7% Eleje et al)
Incidence of chorioamnionitis following PROM
13-60%
(53.4% Eleje et al)
Incidence of IUFD following PROM
1%
(8.7% Eleje et al)
Incidence of abruptio placentae as a consequence of PROM
4%
Incidence of non-reassuring fetal status as a consequence of PROM
8%
T/F: Latency increases with early EGA, AFI
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4 natural history of PROM in terms of delivery
- Delivery in 48hrs
- Delivery in 1 week
- Delivery in > 4 weeks
- Reseal
% of women with PROM that will deliver in 48hrs
30 - 50%
% of women with PROM that will deliver in 1 week
90 - 93%
% of women with PROM that will deliver in > 4 weeks
10%
% of PROM that will reseal
3 - 10%
9 risk factors for PROM
- Chorioamnionitis
- Vaginal infections
- Cervical abnormalities
- Vascular pathology (incl.
abruptio) - Smoking
- 1st, 2nd, 3rd, or multiple
trimester bleeding - Previous preterm delivery
(PPROM) - Acquired or congenital
connective tissue disorder - Nutritional deficiencies (Vit.C,
copper, zinc)
T/F: PROM can result from APH in any trimester
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3 examples of nutritional deficiencies that can lead to PROM
Vit. C
Copper
Zinc
6 mechanisms of preterm PROM
- Bacterial production of proteases
- Host response to blood or bacteria (MMP 1,2,9) or (TIMP1,3)
- Pre-existing weakness
- Strain from preterm uterine activity
- Direct membrane trauma (cerclage or amnio)
- Developmental “weak spot”
T/F: Mechanisms of preterm PROM can include:
ascending infection, stretch, necrosis and decidual adherence
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2 mechanisms of PROM at term
a normal physiologic weakening of the membranes combined with shearing forces created by uterine contractions
T/F: In the history of PROM, the patient reports a “Gush” of fluid or steady leakage of small amounts of fluid
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T/F: Digital examination of the cervix with PPROM has been shown to shorten latency and increase risk of infections
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For the ferning test, the slide should be allowed to dry for how long
10 mins
pH of amniotic fluid
Alkaline
7.1 - 7.3
Normal pH of vaginal secretions
3.8–4.5
Effect of amniotic fluid on nitrazine
Turns nitrazine pH indicator blue
Sensitivity of nitrazine test
90.7%
Specificity of nitrazine test
77.2%
% of false positive nitrazine test
17.4%
% of false negative nitrazine test
12.9%
Other fluids and infections can result in false positive nitrazine test
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Sensitivity of the ferning test
51.4%
Specificity of the ferning test
70.8%
% false positive results in fern test
5-30%
% false negative results in fern test
12.9%
Drawbacks of the fern test
Requires speculum exam, microscope with risks of contamination.
5 causes of false positive nitrazine test
Alkaline urine
Semen (recent coitus)
Cervical mucus
Blood contamination
Vaginitis (e.g. Trichomonas)
2 reasons for false negative nitrazine test
Remote PROM with no residual fluid
Minimal amniotic leakage
What are the drawbacks of pooling as a technique of PROM diagnosis
Speculum exam. Subjective. Other fluids
T/F: USS is a reliable screening test for PPROM
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Not a reliable screening test if used alone
Used only to help confirm
Diagnosis
% of women with PPROM that have reduced amniotic fluid on USS
50 - 70%
Gold Standard for diagnosis of rupture of membranes
Amnio-dye infusion