Preterm Labor & PROM

Preterm Labor When onset of labor prior to completion of 37 weeks (259 days) of pregnancy, after the attainment of period of viability is called preterm labor. The lower limit varies in different countries WHO- 22wks and 500gm United kingdom- 24wks India- 28wks

Incidence It varies 5-15% in different part of world & India Aetiology In >30% cases exact cause of preterm labor is not known Certain risk factors which increases the incidence of preterm labor.

Risk factors Genital tract infection- Group B streptococci - Bacterial Vaginosis - Chlamydia, Gonorrhea Ante partum Hemorrhage Overdistended Uterus- polyhydromnios - Multiple pregnancy Uterine anomalies - unicornuate,Bicornuate -septate,arcuate, Fibroid uterus

Incompetent Cervical os Acute fever & maternal illness Premature rupture of membrane Low socioeconomic status, poor nutrition, & anaemia Smoking & tobacco addiction U T I Pervious H/o preterm labor (17-40%) Iatrogenic- Induction of labor without knowing EDD

Diagnosis of PTL P/A- Regular uterine contractions > 4 in 20 minutes or >8 in 60 minutes, with changes in cervix Cervical effacement >80% Cervical dilatation > 1 cm

Preterm Labor Can be 1. Advanced PTL 2. Early PTL 3. Threatened PTL

Advance PTL Diagnosis: -Regular uterine contraction >4 in 20 mts or >8 in 60 mts -Cervix >3 cm dilated - 80% effaced

Management of Advanced PTL Allow delivery if -Cx is >4cm dilated -Signs of chorioamnionitis -Baby malformed -Severe placental insufficiency But if Cx is <4cm and none of the above is present give tocolysis,corticosteroid & antibiotic if indicated Aim – to give corticosteroid to prevent RDS &IVH in baby & mother with fetus in utero can transfer to place where neonatal care facility available

Early PTL -Regular uterine contraction Diagnosis: -Regular uterine contraction -Cervix > 1 cm & <3 cm dilated -Cervix > 80% effaced

Management of Early PTL If there is signs of – Chorioamnionitis - Congenital anomaly in fetus - Mother& fetus condition is not good Allow labour and delivery.

But if - Fetal condition is not compromised - Maternal condition is good - No signs of chorioamnionitis - Membranes are intact Then Expectant management includes- - Bed rest in left lateral position - Antibiotic if infection is evident - Tocolysis - Corticosteroid if pregnancy < 34 weeks

Threatened PTL When there are regular uterine contractions, Cervix is <1cm dilated , length of cervix <2.5cm on USG & GA <37 wks- Threatened PTL Diagnosis is by – Clinical examination - USG - Detection of fetal fibronectin in cervical discharge FFN in cervical discharge is usually absent between 24-34wks , so if it is present it is predictor of PTL

If FFN is negative in cervical discharge indicates no delivery with in 7 days. If threatened PTL is diagnosed by clinically, USG & FFN then give tocolysis and corticosteroid to woman.

Doses of Corticosteroids Betamethasone- 2 doses,12mg IMI,24 hours apart. OR Dexamethasone- 6mg IMI 12 hrly total 4 doses Corticosteroids are beneficial when delivery occurs at least 48 hrs after 1st dose

Tocolytic Drugs Various tocolytic drugs which can be used are :- * Nefedipine * Betamimetics –Isoxsuprine -Terbutaline - Retrodine * Indomethacin * Mgso4 * Nitroglycerine

Doses of Tocolytic drugs Nefedipine It is the best first line tocolytic It is a calcium channel blocker causes smooth muscles relaxent Doses – Initial 20-30mg orally followed by 10mg 4-6hrly till uterine contraction cease f/b 10mg 8hrly for about 1wk. Side effects- headach,hypotension,nausea flushing

Bitamimetic Tocolytics Turbutaline It can be given IV or subcutaneous For IV- Dissolve 5mg of terbutaline in 500ml of RL, each ml contains 10ug -Start with 5ug (o.5ml)/min. & increase the dose of 5ug every 10-20min.till uterine contraction stops. -Maximum dose 30ug/min. Subcutaneous dose-o.25mg every 3-4 hours for 12hrs A maintenance dose-2.5-5mg orally 4-6 times/day

Ritodrine Beta mimetic drug causes smooth muscle relaxation by B2 receptor stimulation Doses- given by IV infusion - Start with 100ug/min. & increase the dose by 50ug every 10-20 min. till the uterine contraction stops or maximum dose of 350ug - Continue infusion for 12hrs after the contractions stop.

Isoxsuprine Doses- 0.2-0.5mg/min I V infusion for 12hrs followed by 10mg IMI every 6-8 hour for 24hours Side effects of Beta mimetics Headache Palpitation , Tachycardia Hypotension , Hypokalemia Pulmonary oedema & Cardiac failure

Indomethacin It is an excellent tocolytic but is not used as first line because it causes constriction of ductus arteriosis. Dose – Initial dose 25-50mg orally followed by 25mg every 4-6 hours for 3days. Side effects – Heart burn, G.I.bleeding Thrombocytopenia, asthma

Mgso4 Dose – 4-6 gm (20% solution) i.v. slow in 20-30 min. followed by an infusion of 1-2gm/hr & continue for 12 hrs after the contraction have stopped Side effects- Headache , flushing - Muscular weakness - Rarely pulmonary oedema

Nitro-glycerine It is usually given in form of patch Dose – 0.1- 0.4 mg/ hr Side effects – Tachycardia - Headache - Hypotension

(PROM) Premature Rupture Of Membranes or Prelabour Rupture Of Membranes Spontaneous rupture of fetal membrane any time after the period of viability but before the onset of labor is called PROM. When it occurs before 37 wks completed gestation it is called PPROM. Incidence – 10%

Causes of PROM Polyhydromnios Multiple pregnancy Incompetent Cervix Poorly applied presenting part in unstable lie and malpresentations Traumatic- ECV, amniocentesis Weakness of chorion & amnion- developmental or inflammatory,chorioamnionitis

Diagnosis H/O- discharge of fluid p/v P/S- examination shows liquor coming out through cervical os it may be clear or meconium stained. Sometimes liquor is not appreciable through os D/D – liquor amnii - urine - vaginal discharge

Confirmatory Tests for liquor Amnii Fern Test- Take the sample of vaginal fluid on a slide & allow it to dry then look under microscope. Crystallization of liquor looks like fern. Nitrazine Test- Normal vaginal PH is 4.5-5.5 but PH of liquor is 7-7.5. Put the Nitrazine paper on vaginal discharge Liquor turns the Nitrazine paper deep blue. Nile blue sulphate Test- when centrifuged cells of watery discharge is stained with Nile blue sulphate it shows, orange blue coloration of cells indicates presence of exfoliating fetal cells in liquor

Indigo-carmine Test- When other tests are negative and still doubt of leaking. Inject 2-3cc of indigo carmine in amniotic cavity & put a tampon in vagina wt. for ½-1hr if tampon turns blue indicate liquor. Detection of fetal fibronectin in endocervix & vagina between 24-34 wks of GA indicates PROM USG - Shows less liquor

Hazards of PROM Maternal- Increased liability to infection - chorioamnionitis - Premature placental separation - Postpartum endometritis Fetal - Cord prolapse - Premature labor & hyaline membrane disease - Intrauterine Infection

Management ofPROM Initial Assessment- main objective of the initial assessment are:- - Confirm the diagnosis of PROM - To determine the gestation of the fetus - To identify the women who need to deliver

Management of PROM If Pregnancy is ->37 weeks - Congenital anomalies - Fetal distress , cord prolapse or - Signs of chorioamnionitis Then deliver the patient. Induction of labor- if no contraindication

Management of PPROM Balance between risk of infection in expectant management & Premature labor Shift the patient where the facility for neonatal care is available . If pregnancy is >34 and <37 weeks - Haemogram, cervical swab c/s - Antibiotics - Careful watch on signs of chorioamnionitis Maternal & fetal conditions - If no spontaneous labor in 24-48hrs-induction of labor

If pregnancy <34 weeks Expectant Management- The aim is to prolong the pregnancy for fetal maturity - Bed rest - send haemogram & Cervical swab c/s - give corticosteroid & tocolysis if contraction +nt - Antibiotics - Watch for signs of chorioamnionitis, Maternal & fetal condition.

Signs of chorioamnionitis Temperature > 100.4*F and 2 or more of: -Maternal tachycardia pulse >100/min. -Uterine Tenderness - Foul smelling vaginal discharge - Leukocytosis15000cmm - C-reactive protein >2.5mg% - Fetal tachycardia >160 min if there is no other site of infection