Interpretation
Our findings are partially in line with the most recent Cochrane
systematic review, confirming that there is evidence of higher OVD rate
in IOL at 40 GW vs IOL at 41 GW.8 Discrepancies
between our results for CS rates and other studies8,
10, 13, 15, 35 could be accounted for by differences in setting, study
design, and different definitions of comparison groups. Our study was
set in Sri Lanka and includes recent data from a maternity hospital
registry, evaluating optimal timing of IOL in routine circumstances in a
LMIC setting at predefined GW. Only 9 of 30RCTs included in the Cochrane
review were conducted in LMIC, while 13 (43%) studies were published
from 1960s-1980s.19 Furthermore, comparison groups in
the Cochrane review are not directly comparable since timing of IOL
differed among included trials as well as group definition, timing, and
monitoring of expectant management.
Moreover, while RCT would be the most appropriate study design to
address the question of optimal timing of IOL, this design has potential
limitations. As shown in the two most recent RCTs comparing IOL at term
versus expectant management11, 14, recruiting women
for such trials is extremely difficult. In both trials a high number of
women declined participation (73% in the US study and 78% in the
Swedish study). This could have affected the characteristics of the
sample and the generalizability of findings. Moreover, it highlights the
fact that the views of women on onset of labour can be strong, both in
refusing or requesting induction. This underscores the need for
patient-centered care which takes into account the perspective of
patients,36 as well as for more research on women’s
preferences and views. Another limitation of RCTs is that the
intervention cannot be masked, thus being open to possible bias due to
differences in treatment/monitoring by allocation group. The
availability of a prospective database capturing characteristics and
outcomes of each delivery provides the opportunity to easily monitor
indicators over time and compare practices and results in a real world
setting.
Overall, findings of this study highlight the need for caution in
generalizing the results of RCT conducted in high income settings to
different clinical settings and populations. More studies should be
conducted to further explore the ideal timing of IOL in LMICs.
CONCLUSIONS
Women with low risk pregnancies
who underwent elective induction at 40 GW or induction at 41 GW in
Colombo, Sri Lanka had significantly increased risk of negative birth
outcomes (CS, OVD or any complication) compared to women with
spontaneous onset of labour. While more evidence is needed on a global
level to further understand the optimal timing of IOL in settings with
low resources, these findings should be used to improve monitoring and
routine practices in Sri Lanka, as well as in other LMIC where IOL is
frequent practice.
ACKNOWLEDGMENTS
We would like to thank the staff of the Professorial Unit of the De
Soysa Hospital and the Medical Records Officer and his staff for
assisting with this study.
We are thankful to dr. Rebecca Lundin, for the English language review.
DISCLOSURE OF INTERESTS
No competing interests.
FUNDING
The implementation of the database was funded for the first year by a
grant from the GREAT Network, Canadian Institutes of Health Research,
St. Michael’s Hospital, Toronto
AUTHOR CONTRIBUTIONS
HS and ML conceived the study and procured funds.
IM analysed data.
HS, IM, EPV, BA, MP, CB, MR, BC, and ML interpreted data and contributed
to the manuscript.
All authors revised and approved the final manuscript.
REFERENCES
1. Organization WH. WHO recommendations: induction of labour at or
beyond term. Geneva2018.
2. WHO. World Health Organization. WHO recommendations for Induction of
labour. 2011.
3. NICE. National Institute for Health and Clinical Excellence.
Induction of labour: NICE clinical guideline 70. Manchester.
Manchester2008.
4. Senanayake H. HNE. National Guidelines for Maternal and Newborn Care
Volume 1. Family Health Bureau, Ministry of Health, Colombo .
2013;
5. Delaney M, Roggensack A. No. 214-Guidelines for the Management of
Pregnancy at 41+0 to 42+0 Weeks. Practice Guideline. Journal of
Obstetrics and Gynaecology Canada . 08/01/August 2017
2017;39(8):e164-e174. doi:10.1016/j.jogc.2017.04.020
6. WHO. World Health Organization. WHO recommendations: induction of
labour at or beyond term. Geneva2018.
7. Coates D, Homer C, Wilson A, et al. Induction of labour indications
and timing: A systematic analysis of clinical guidelines. Women
Birth . May 2020;33(3):219-230. doi:10.1016/j.wombi.2019.06.004
8. Middleton P, Shepherd E, Crowther CA. Induction of labour for
improving birth outcomes for women at or beyond term. Cochrane
Database of Systematic Reviews .
2018;(5)doi:10.1002/14651858.CD004945.pub4
9. Muglu J, Rather H, Arroyo-Manzano D, et al. Risks of stillbirth and
neonatal death with advancing gestation at term: A systematic review and
meta-analysis of cohort studies of 15 million pregnancies. PLoS
Med . Jul 2019;16(7):e1002838. doi:10.1371/journal.pmed.1002838
10. Walker KF, Bugg GJ, Macpherson M, et al. Randomized Trial of Labor
Induction in Women 35 Years of Age or Older. New England Journal
of Medicine . 2016/03/03 2016;374(9):813-822. doi:10.1056/NEJMoa1509117
11. Grobman WA, Rice MM, Reddy UM, et al. Labor Induction versus
Expectant Management in Low-Risk Nulliparous Women. N Engl J Med .
Aug 9 2018;379(6):513-523. doi:10.1056/NEJMoa1800566
12. Grobman WA, Caughey AB. Elective induction of labor at 39 weeks
compared with expectant management: a meta-analysis of cohort studies.
Review Article. American Journal of Obstetrics and Gynecology .
10/01/October 2019 2019;221(4):304-310. doi:10.1016/j.ajog.2019.02.046
13. Keulen JK, Bruinsma A, Kortekaas JC, et al. Induction of labour at
41 weeks versus expectant management until 42 weeks (INDEX):
multicentre, randomised non-inferiority trial. BMJ . Feb 20
2019;364:l344. doi:10.1136/bmj.l344
14. Wennerholm UB, Saltvedt S, Wessberg A, et al. Induction of labour at
41 weeks versus expectant management and induction of labour at 42 weeks
(SWEdish Post-term Induction Study, SWEPIS): multicentre, open label,
randomised, superiority trial. BMJ . Nov 20 2019;367:l6131.
doi:10.1136/bmj.l6131
15. Rydahl E, Declercq E, Juhl M, Maimburg RD. Routine induction in
late-term pregnancies: follow-up of a Danish induction of labour
paradigm. BMJ Open . 2019;9(12):e032815.
doi:10.1136/bmjopen-2019-032815
16. Rydahl E, Eriksen L, Juhl M. Effects of induction of labor prior to
post-term in low-risk pregnancies: a systematic review. JBI
Database System Rev Implement Rep . Feb 2019;17(2):170-208.
doi:10.11124/jbisrir-2017-003587
17. Coates R, Cupples G, Scamell A, McCourt C. Women’s experiences of
induction of labour: Qualitative systematic review and thematic
synthesis. Midwifery . Feb 2019;69:17-28.
doi:10.1016/j.midw.2018.10.013
18. Downe S, Finlayson K, Oladapo OT, Bonet M, Gülmezoglu AM. What
matters to women during childbirth: A systematic qualitative review.PLoS One . 2018;13(4):e0194906. doi:10.1371/journal.pone.0194906
19. Vogel JP, Souza JP, Gülmezoglu AM. Patterns and Outcomes of
Induction of Labour in Africa and Asia: A Secondary Analysis of the WHO
Global Survey on Maternal and Neonatal Health. PLOS ONE .
2013;8(6):e65612. doi:10.1371/journal.pone.0065612
20. Yim C, Wong L, Cabalag C, Wallace EM, Davies-Tuck M. Post-term
surveillance and birth outcomes in South Asian-born compared with
Australian-born women. J Perinatol . Feb 2017;37(2):139-143.
doi:10.1038/jp.2016.190
21. Cox AG, Narula S, Malhotra A, Fernando S, Wallace E, Davies-Tuck M.
The influence of maternal ethnicity on neonatal respiratory outcome.Arch Dis Child Fetal Neonatal Ed . Jan 2020;105(1):50-55.
doi:10.1136/archdischild-2018-316418
22. Balchin I, Whittaker JC, Patel RR, Lamont RF, Steer PJ. Racial
variation in the association between gestational age and perinatal
mortality: prospective study. BMJ . Apr 21 2007;334(7598):833.
doi:10.1136/bmj.39132.482025.80
23. STROBE. STROBE Statement. STrengthening the Reporting of
OBservational studies in Epidemiology. 2009.https://www.strobe-statement.org/index.php?id=strobe-home.
Accessed 15 Jul 2020.
24. Lazzerini M, Senanayake H, Mohamed R, et al. Implementation of an
individual patient prospective database of hospital births in Sri Lanka
and its use for improving quality of care. 2019.
25. Consultation WWHOE. Appropriate body-mass index for Asian
populations and its implications for policy and intervention strategies.Lancet . 2004;363 North American Edition(9403):157-163.
doi:10.1016/s0140-6736(03)15268-3
26. Senanayake H, Piccoli M, Valente EP, et al. Implementation of the
WHO manual for Robson classification: an example from Sri Lanka using a
local database for developing quality improvement recommendations.BMJ open . 2019;9(2):e027317. doi:10.1136/bmjopen-2018-027317
27. Bligard KH, Lipsey KL, Young OM. Simulation Training for Operative
Vaginal Delivery Among Obstetrics and Gynecology Residents A Systematic
Review. OBSTETRICS AND GYNECOLOGY . 10/01/ 2019;134:16S-21S.
doi:10.1097/AOG.0000000000003431
28. Bailey PE, van Roosmalen J, Mola G, Evans C, de Bernis L, Dao B.
Assisted vaginal delivery in low and middle income countries: an
overview. BJOG-AN INTERNATIONAL JOURNAL OF OBSTETRICS AND
GYNAECOLOGY . 08/01/ 2017;124(9):1335-1344. doi:10.1111/1471-0528.14477
29. Jordal M, Wijewardena K, Olsson P. Unmarried women’s ways of facing
single motherhood in Sri Lanka - a qualitative interview study.BMC Womens Health . Feb 6 2013;13:5. doi:10.1186/1472-6874-13-5
30. Raifman S, Cunha AJ, Castro MC. Factors associated with high rates
of caesarean section in Brazil between 1991 and 2006. Acta
Paediatr . Jul 2014;103(7):e295-9. doi:10.1111/apa.12620
31. Mostafa Kamal SM. Preference for institutional delivery and
caesarean sections in Bangladesh. Article. Journal of Health,
Population and Nutrition . 03 / 01 / 2013;31(1):96-109.
32. Boatin AA, Schlotheuber A, Betran AP, et al. Within country
inequalities in caesarean section rates: observational study of 72 low
and middle income countries. 2018.
33. Zimmo M, Fosse E, Lieng M, et al. Differences in rates and odds for
emergency caesarean section in six Palestinian hospitals: A
population-based birth cohort study. Article. BMJ Open . 03 / 01 /
2018;8(3)doi:10.1136/bmjopen-2017-019509
34. Wehberg S, Guldberg R, Gradel KO, et al. Risk factors and
between-hospital variation of caesarean section in Denmark: A cohort
study. Article. BMJ Open . 02 / 01 /
2018;8(2)doi:10.1136/bmjopen-2017-019120
35. Coates D, Makris A, Catling C, et al. A systematic scoping review of
clinical indications for induction of labour. PLoS One .
2020;15(1):e0228196. doi:10.1371/journal.pone.0228196
36. Einerson BD, Grobman WA. Elective induction of labor: friend or foe?
Review Article. Seminars in Perinatology . 03/01/March 2020
2020;44(2)doi:10.1016/j.semperi.2019.151214
TABLE/FIGURE CAPTION LIST
Figure 1. Study sample selection
Table 1. Characteristics of the study population
Figure 2. Births with negative
outcomes by type of labour
Table 2. Adjusted odds ratios for negative birth outcomes by type of
labour
Table 1. Characteristics of the study population