Delivery Flashcards
Premature rupture of the membranes
PROM
the rupture of fetal membranes at least 1 hour prior to the onset of labour, at ≥37 weeks gestation.
It occurs in 10-15% of term pregnancies, and is associated with minimal risk to the mother and fetus due to the advanced gestation.
Pre-term premature rupture of the membranes (P-PROM)
the rupture of fetal membranes occurring at <37 weeks gestation.
It complicates ~2% of pregnancies and has higher rates of maternal and fetal complications. It is associated with 40% of preterm deliveries.
Pathophysiology of PROM
Early activation of normal physiological processes – higher than normal levels of apoptotic markers and MMPs in the amniotic fluid.
Infection – inflammatory markers e.g. cytokines contribute to the weakening of fetal membranes.
Genetic predisposition
Prolonged rupture of membranes
amniotic sac ruptures more than 18 hours before delivery
risk factors PROM/P-PROM
smoking previous PROM-pre-term delivery vaginal bleeding during pregnancy lower genital tract infection invasive procedures, e.g. amniocentesis multiple pregnancy cervical insufficiency
Prematurity classification
Under 28 weeks: extreme preterm
28 – 32 weeks: very preterm
32 – 37 weeks: moderate to late preterm
clinical features of PROM
painless popping sensation
gush of water
gradualleakage of watery fluid from the vagina
fluid draining from cervix and pooling in posterior vaginal fornix
washed cleann- lack of normalvaginal discharge
options for prophylaxis of pre-term labour
vaginal progesterone
cervical cerclage
vaginal; progesterone for prophylaxis of pre-term labour
Progesterone can be given vaginally via gel or pessary as prophylaxis for preterm labour. Progesterone has a role in maintaining pregnancy and preventing labour by decreasing activity of the myometrium and preventing the cervix remodelling in preparation for delivery. This is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation.
cervical cerclage for prophylaxis of pre-term labvour
Cervical cerclage involves putting a stitch in the cervix to add support and keep it closed. This involves a spinal or general anaesthetic. The stitch is removed when the woman goes into labour or reaches term.
Cervical cerclage is offered to women with a cervical length less than 25mm on vaginal ultrasound between 16 and 24 weeks gestation, who have had a previous premature birth or cervical trauma (e.g. colposcopy and cone biopsy).
“Rescue” cervical cerclage may also be offered between 16 and 27 + 6 weeks when there is cervical dilatation without rupture of membranes, to prevent progression and premature delivery.
PROM differentials
urinary incontinence normal vaginal secretions of pregnancy increased sweat/moisture arounbd perineum increased cervical discharge vesicovaginal fistula loss of mucus plug
investigations for PROM
high vaginal swab for GBS, figure out cause (BV) ferning test actim-PROM amnisure nitrazine testing
ferning test
placing cervical secretion onto a glass slide and allowing it to dry (forming fern-patterned crystals if there is PROM/PPROM). The false positive rate is around 6%.
Actim-PROM (Medix Biochemica)
uses a swab test looking for IGFBP-1 (insulin-like growth factor binding protein-1) in vaginal samples. The concentration in amniotic fluid is 100 – 1000 times the concentration of maternal serum. This test is unlikely to be affected by blood contamination
Amnisure (QiaGen) –
looks for Placental alpha microglobulin-1 (PAMG-1) which is present in the blood, amniotic fluid (in large concentrations) and cervico-vaginal discharge of pregnant women (in low concentrations with membranes intact).
Nitrazine testing
measures the pH of vaginal fluids and has previously been used to diagnose PROM and PPROM (amniotic fluid pH is higher than vaginal fluids). However, this test carried a high false positive rate (17%), due to contamination with urine, blood or semen – and is no longer routinely used.
PROM management >36 weeks
Monitor for signs of clinical chorioamnionitis.
Clindamycin/penicillin during labour if GBS isolated.
Watch and wait for 24 hours (60% of women go into labour naturally), or consider induction of labour.
IOL and delivery recommended if greater than 24 hours (but women can wait up to 96 hours – beyond this is their choice after counselling)
PROM management 34-36 weeks
Monitor for signs of clinical chorioamnionitis, and advise patient to avoid sexual intercourse (can increase risk of ascending infection).
Prophylactic erythromycin 250 mg QDS for 10 days.
Clindamycin/penicillin during labour if GBS isolated.
Corticosteroids if between 34 and 34+6 weeks gestation.
IOL and delivery recommended.
24-33 weeks PROM management
Monitor for signs of clinical chorioamnionitis, and advise patient to avoid sexual intercourse.
Prophylactic Erythromycin 250 mg QDS for 10 days.
Corticosteroids (as less than 34+6).
Aim expectant management until 34 weeks.
diagnossi Pre-term labour with intact membrANES
Clinical assessment includes a speculum examination to assess for cervical dilatation. The NICE guidelines (2017) recommend:
Less than 30 weeks gestation, clinical assessment alone is enough to offer management of preterm labour.
More than 30 weeks gestation, a transvaginal ultrasound can be used to assess the cervical length. When the cervical length on ultrasound is less than 15mm, management of preterm labour can be offered. A cervical length of more than 15mm indicates preterm labour is unlikely.
fetal fibronectin
fetal fibronectin in diagnosis pre-term labour with intact,membranes
Fetal fibronectin is an alternative test to vaginal ultrasound. Fetal fibronectin is the “glue” between the chorion and the uterus, and is found in the vagina during labour. A result of less than 50 ng/ml is considered negative, and indicates that preterm labour is unlikely.
pre-term labour with intact membranes
regular painful contractions
cervical dilatation without rupture of amniotic sac
management of pre-term labour
Fetal monitoring (CTG or intermittent auscultation)
Tocolysis with nifedipine: nifedipine is a calcium channel blocker that suppresses labour
Maternal corticosteroids: can be offered before 35 weeks gestation to reduce neonatal morbidity and mortality
IV magnesium sulphate: can be given before 34 weeks gestation and helps protect the baby’s brain
Delayed cord clamping or cord milking: can increase the circulating blood volume and haemoglobin in the baby at birth
