Methods:
The study was approved by the Human Research Ethics Committee in the ACT
(reference number 2019/ETH12446; approved 17 July 2019). The
intervention was the PTB prevention initiative and the main outcomes
measured were rates of PTB and early term birth before and after
implementation of the initiative.
The PTB prevention initiative was a multifaceted initiative. Initially a
guideline on the prevention and management of PTB was developed and a
three-month program of outreach education and dissemination of the new
clinical guidelines took place with sonographers, obstetricians,
midwives and general practitioners across the territory and surrounding
southern New South Wales (NSW) areas. The initiative was officially
launched on 28 February 2019 and received philanthropic support to
establish the service and Ministerial endorsement.
The key interventions in the new clinical guidelines for the ACT were
based on the WA initiative.
These included:
- universal screening of cervical length at all routine 18-20 week fetal
anomaly ultrasound scans
- prescription of vaginal progesterone pessary for women who have a
shortened cervix (≤25mm) on
ultrasound (between 16-24 weeks)
- prescription of vaginal progesterone pessary for all women with a
history of spontaneous preterm birth (24-34 weeks) or spontaneous loss
(16-24 weeks)
- consideration of cervical cerclage for cervical length <10mm
- avoidance of early planned birth unless medically indicated
- implementation of a structured smoking cessation program
- implementation of a dedicated preterm birth prevention clinic.
After the launch, further multidisciplinary education sessions were
organised for sonographers, general practitioners, midwives and
obstetricians throughout the ACT and hospitals in the southern NSW and
Murrumbidgee districts.
The new PTB prevention clinic was established within the Fetal Medicine
Unit (FMU) at CHWC. CHWC is the sole tertiary level centre for referral
of high-risk pregnancies for the ACT and surrounding NSW areas. Thus,
the initiative aimed to capture all women with an increased risk of PTB.
Referrals were made through the FMU and were triaged as a priority. The
clinic is staffed by an Obstetrician, a Fetal Medicine Fellow, a
midwife, a sonologist and sonographers. Continuity of care was offered
to all women or they could refer back to their original care provider
once the early risk of PTB had passed.
A pre and post intervention study was conducted to examine the
association between the PTB prevention initiative and preterm and early
term birth rates. Our analysis included women who gave birth at the CHWC
in the pre intervention period from 1 January 2014 to 31 December 2018
and the post intervention period from 1 January 2019 to 30 April 2020.
Inclusion criteria included women who had a singleton birth between
20-39 weeks gestation within the study period. Rates of PTB and early
term birth before (2014-2018) and after 16 months of implementation of
the initiative were evaluated. Rates of early birth were assessed using
run charts of bimonthly preterm and early term rates from 2014-2020. Run
charts show patterns of change over time and can identify trends, runs
and how an intervention is performing.
Data was collected from the Central Birth Outcome System electronic
medical record. This system collects all births from 20 weeks of
pregnancy at the CHWC. Retrospective collection of existing records
occurred for both the pre intervention and post intervention groups.
Data included demographic information, gestational age at birth,
plurality, birth outcomes and whether births were spontaneous or
iatrogenic. All data was de-identified and the study did not require
patient involvement. Discrete data were reported as number and percent
and compared using Chi Square tests. A p-value of 0.05 was considered
significant.