RSU studies cervical insufficiency – a risk factor for preterm birth
Writers: Ludmila Voložonoka, RSU lead researcher, molecular geneticist,
Dace Rezeberga, RSU professor, gynaecologist, chief obstetrician at Riga Maternity Hospital, chief specialist in obstetrics and gynaecology at RAKUS,
Anna Miskova, RSU associate professor, Dr. med., gynaecologist, specialist in obstetrics at Riga Maternity Hospital
Doctors have long been uncertain about how to help women with premature cervical shortening, which puts them at risk of premature birth or losing the baby.
A seven-year-long study by Rīga Stradiņš University (RSU) is now helping doctors advise pregnant women and decide whether to offer them surgical treatment – cervical cerclage.
Latvia has one of the lowest rates of preterm births in Europe – 5.1–5.4% of all births (compared to an average of 6% and up to 10% or more elsewhere). However, each such event is a major psycho-emotional burden for the family, and the cost of treating premature babies is high. It is therefore important to reduce the number of premature births in Latvia as well.
Premature cervical shortening, or cervical insufficiency, puts pregnant women at risk of premature birth or losing the baby. However, doctors have long been uncertain about which method to use to help women with this condition; causes of the condition can vary and are not always easy to identify, and treatment options differ depending on the cause. A study conducted at RSU and the Riga Maternity Hospital on cervical insufficiency is now aiding doctors in the counselling they provide and gives them more confidence to offer surgical treatment, cervical cerclage, to pregnant women in certain situations, while encouraging them to refrain from it in others.
The scientific part of the study has made it possible to completely change the treatment approach for every patient with a shortened cervix, thus improving treatment outcomes.
Key findings and crucial takeaways
In cases where there is a risk of preterm birth, there are a limited number of treatment options available. The study found that signs of intrauterine infection can be successfully detected indirectly and clinically and used to justify the need for antimicrobial therapy, which can improve the prognosis of pregnancies. Data showed that patients with a shortened cervix and signs of intrauterine infection are four times more likely to go into preterm labour than other pregnant women.
Identifying these indirect signs helps doctors provide counselling and gives them a reason for offering or not offering patients cervical cerclage.
There is a theory that preterm birth could be genetically inherited. During the research process, a rare pathogenic variant (commonly known as a mutation) in the PGR gene (progesterone receptor gene) and the NR3C1 gene (glucocorticoid receptor gene) were discovered for the first time, that might be associated with cervical insufficiency. The authors of the study recommend progesterone therapy until the 36th week of pregnancy in patients with premature cervical shortening. Prescribing additional progesterone has been shown to be an effective way of reducing the risk of miscarriage throughout pregnancy.
The following protocol is currently recommended in Latvia: if the cervix is shortened, patients are offered progesterone; if the cervix is particularly shortened, patients are offered both progesterone and a cerclage.