Universal screening for short cervical length could cut preterm births

A short cervical length in mid-pregnancy can dramatically increase the risk of preterm birth and most cases of preterm birth occur with no prior history. A team of researchers from The University of Western Australia (UWA) said that measuring the length of a woman’s cervix at mid-pregnancy can help decrease the risk of preterm delivery.

Preterm birth is the largest cause of infant death and occurs in 8% of births in Australia (26,000 babies every year).

The UWA team is part of a state-wide initiative, The Western Australian Preterm Birth Prevention initiative, which aims to lower the rate of preterm birth across WA.

Lead researcher and PhD student Michelle Pedretti, from UWA’s School of Women’s & Infants’ Health, said as part of the initiative, the team was visiting doctors and medical professionals throughout the state to help them understand the importance of cervical length screening during mid-pregnancy.

“We are also helping medical practitioners evaluate the best ways of screening the cervix, using an ultrasound,” Pedretti said.

“For women at low-risk of preterm birth it has been suggested a transabdominal ultrasound is one way to assess the cervical length, but emerging data on this is now showing this is not as accurate as the transvaginal method.”

Women’s attitudes towards the two scanning methods are also being investigated by the researchers.

“An imaging technique is important to achieve the most accurate measurement of the cervical length in mid-pregnancy and the education of medical practitioners has been shown to be effective in increasing both the competency and quality of the cervical length measurement. There are several cervical length competency courses available to sonographers and imaging staff,” she said.

Pedretti said that currently there was great debate about whether to implement cervical length screening in all pregnancies or just restrict it to those at the greatest risk.

“Opponents to cervical length screening have raised concerns about the lack of universal access there is to a transvaginal ultrasound (the method of choice for cervical length measurement), and the need for standardised protocols such as consistent measurement, treatment standards and cost effectiveness of treatments,” she said.

Given that there are treatments available to reduce the risk once it’s identified, there appears to be a clear role for routine cervical length screening as part of the regular pregnancy ultrasound examinations.

Pedretti explained, “There is also strong evidence supporting the use of vaginal progesterone in women with a short mid-pregnancy cervix to significantly reduce the risk of preterm birth. This is effective mainly for women carrying one baby but recent data is now demonstrating it is effective for twin pregnancies too.”

The research has been published in the ANZJOG Journal.

Image credit: ©stock.adobe.com/au/Halfpoint