A pregnant patient comes at 34 weeks gestation with leaking. What examination will reliably confirm premature rupture of membranes in this patient?
Ans: (a) Speculum examinationRef: DC Textbook of Obstetrics, 8th edition, Page 369PREMATURE RUPTURE OF MEMBRANES (PROM)Spontaneous rupture of membranes anytime beyond 28th week but before the onset of labour is called prelabour rupture of the membranes.When it occurs before 37 completed weeks it is called preterm PROM (PPROM)Causes:PolyhydramniosCervical incompetenceMultiple pregnancyChorioamnionitisLow BMIConfirmation of diagnosis:Speculum examination-Most confirmatoryVaginal pool for pH-6-6.2, ferning pattern, orange blue discoloration of exfoliated cellsAmnisure radioimmunoassayUltrasoundInvestigationsComplete blood count, C reactive protein, urine routine and cultureHigh vaginal swab for Group B streptococcusVaginal pool for estimation of phosphatidyl glycerol and L:S ratioUSG for fetal biophysical profile, cardiotocographyComplications:ObstetricNeonatal*. Chorioamnionitis*. Neonatal sepsis*. Cord prolapse*. RDS*. Dry labour*. IVH*. Placental abruption*. NECNote:How to diagnosis ruptured membranes?Sterile speculum examination-ruptured membranes are diagnosed if amniotic fluid pools in the posterior fornix or clear fluid flows from cervical canal.Litmus test-PH of vaginal secretions normally ranges from 4.5 to 5.5 whereas that of amniotic fluid is usually 7.0 to 7.5. Therefore red litmus paper turns blueMicroscopic ferning.Nitrazine test-yellow nitrazine paper turns blueArborization or ferning of vaginal fluid-Amniotic fluid crystallizes to form fern like pattern due to relative concentrations of sodium chloride, proteins and carbohydrates.Detection of alphafetoprotein in vaginal vault has been used to identify amniotic fluid.0.1% Nile blue sulfate test (orange coloured cells seen)USG will show oligohydramniosFalse positive test results may occur with coexistent blood, semen, or bacterial vaginosis where results may occur due to scant fluid.
Speculum examination
USG
Non stress test
Amnisure
Physiology & Histology