Preterm labour and new management guidelines

upgrading Knowledge

1. Dr. Sourav Chowdhury Senior Resident P reterm Labour

2. Definitions WHO defines PTL as onset of labour after the gestation of viability and before 37 completed weeks or 259 days of pregnancy.

3. Working Classifications < 28 weeks 28 - < 32 weeks 32 - < 37 weeks The majority of the preterm infants belong to the late preterm subgroup ( Marken et al., 2008) .

4. Criteria for PTL James 4 th Edition High Risk Pregnancy Chap. 61 pg-1075

5. Associations Low socioeconomic status Maternal age Low pregnancy wt. Smoking & substance abuse Multiparity Previous History Infection Cervical Intrumentation or surgery Uterine Abnormalities PROM

6. Screening Uterine contraction monitoring Colton and Associates US preventive service task force Cervical screening by TVS( sogc ) Cervical length (less than 25mm ) Cervical Funneling Fetal Fibronectin ( 50ng/ml ) RCOG 23 rd edition Williams Obstetrics ACOG Practice Bulletin Vol.120 no.4 N Engl J Med 1998;338:15–9. (Level I)

7. Preterm Management Management Preventive Definitive

8. Prevention There is no clear evidence that tocolytic drugs improve outcome and therefore it is reasonable not to use them. However, tocolysis should be considered if the few days gained would be put to good use, such as completing a course of corticosteroids or in utero transfer.

9. Progesterone Cervical Length ≤15mm or prior H/O – spont . Preterm Progesterone group 90-200mg P/V or 17a-Hydroxy P caproate IM Spontaneous delivery before 34 weeks in progesterone group vs placebo significantly less ( 19.2% vs 34.4%; RR 0.56; 95% CI 0.36 to 0.86) No statistical Significant reduction in neonatal morbidity SOGC & ACOG

10. Short Cervix with TVS Singleton Multiple Low risk Group Vaginal Progesterone offered if Cx 20mm or less at or before 24 weeks High risk Group and receiving progesterone since 16-34wks Cerclage should be considered if cervical length is less than25 mm before24 weeks of gestation No intervention improves outcome ACOG

11. Indications Indicated Formulation, dose and route FDA Approved Prior spont . preterm birth Yes 17alpha Hydroxyprogesterone caproate 250mg weekly IM from 16-20weeks to 36weeks Yes Cervical shortening ≤15mm prior to 24 weeks Yes Progesterone suppository 90-200mg vaginally each night from time of diagnosis to 36weeks No Multiple gestations No - No PPROM No - No Positive fFN test No - No Cervical cerclage in place No - No Undelivered after an episode Unclear - No

12. Cervical Circlage History Indicated Circlage Only if 3 or more previous preterm or 2 nd Trimester loss (15% vs 32% p<0.005) Not offered if 2 or less previous preterm or 2 nd trimester loss (14% vs 17% & 12% vs 14%) H/O painless cervical dilatation, rupture of membrane before onset of contraction and additional risk factors are not helpful for decision to place History indicated circlage Usg Indicated If Cx is ≤ 25mm circlage is not indicated if no H/O spontaneous preterm or 2 nd trimester loss ( 22% vs 26%; RR 0.84; 95% CI 0.54 -1.3; p=0.44) Women with singleton pregnancy without Spontaneous Midterm loss or preterm birth should not be offered usg indicated circlage IF Cx is ≤ 25mm before 24 weeks gestation USG indicated circlage not recommended for funneling of cervix in absence of cervical shortening≤ 25mm Rescue C erclage – Cx dilated >1-2cm with or without perceived ut . Contractractions ( with or wihtout membrane bulging)

13. Definitive Corticosteroid Administration Single dose antenatal corticosteroids to women between 24-34 weeks with High risk of preterm birth (level 1++) Ante-natal corticosteroid can be considered for women between 23 rd and 23 +6 (level 2) Ante-natal corticosteroid should be given to all women whom an elective caesarean section planned prior to 38weeks . (level 2) Green-top Guideline no.7 RCOG

14. Tocolysis : There is no clear evidence that tocolytic drug improve outcome therefore it is reasonable not to use them. (level A) -Use them only to gain few days would be put to good use such as corticosteroid course or in- utero transfer Tocolytic drug not associated with clear reduction in perinatal or neonatal mortality or morbidity (level A) Not recommended in suspected preterm labour who had otherwise uncomplicated pregnancy Only in those who benefit by gaining time to Hosiptal or NICU transfer or not completed steroid course

15. Tocolytic Drugs : Nifedepine and Atosiban has comparable effectiveness ( levelA ) Compared to β agonist nifedepine improves neonatal outcome ( levelA ) β agonist have higher side-effects ( levelA ) Nifedepine , Atosiban and COX inhibitor lesser side-effects( levelA ) comparing effectiveness is unclear There is insufficient evidence for any firm conclusions about whether or not tocolysis leads to any benefit in preterm labour in multiple pregnancy Maintenace therapy in threatened preterm is not recommended

16. Antibiotics : In PROM Routine use reduces maternal and neonatal morbidity (level 1a) Choice of antibiotic any penicillin (except co- amoxiclav ) or erythromycin for 10days In Preterm L abour (membrane intact) Use of antibiotic is not at all recommended Kenyon & colleagues study shows neonatal exposure to antibiotic more prone to cerebral palsy at age 7 than non exposed

17. Neuroprotection Magnesium Sulphate Administration of MgSO 4 significant reduction in cerebral palsy in gestation age before 28weeks ( rouse et al ) Administration of MgSO 4 before 30weeks of gestation ( University of Adelaide ) Administration even for multiple gestation For expected delivery within 24hour Even in PROM Can be administer 4hour before delivery ( Australian guidelines )

18. Take Home Message TVS preferred modality for Cx length Fibronectin level positivity between 24-34 wks- asso with PTL No usefulness of routine uterine monitoring ( cost-benefit ) Vaginal Progesterone recomm . for singleton pregnancy( lowrisk ) with CxL <2cm at 24 weeks or more High risk group should given 17alpha Hydroxy Progesterone C aproate Only if 3 or more previous preterm or 2 nd Trimester loss - History indicated cerclage There is no clear evidence that tocolytic drug improve outcome therefore it is reasonable not to use them . Administration of MgSO4 before 30weeks of gestation for Fetal neuroprotection .

19. Thank You !