S‐relaxin as a predictor of preterm delivery in women with symptoms of preterm labour

Abstract

Objective To evaluate whether serum relaxin (S-relaxin) can predict spontaneous delivery before 34 weeks of gestation in high risk pregnancies. Design A prospective cohort study.Setting Calculated sample size was reached over a two-year period, during which 9507 women gave birth. Of these, 157 healthy women were eligible for the study as they were admitted with symptoms of delivery before 34 weeks of gestation. Ninety-three women were included. Overall participation rate was 59%. Population Healthy women with singleton pregnancies with symptoms of delivery before 34 weeks of gestation. Methods S-relaxin was measured using a standard sandwich ELISA.Main outcome measures End points were preterm delivery before 34 weeks of gestation and delivery within three days from initiation of symptoms. The best possible prediction of preterm delivery was established using logistic regression for risk factors individually associated with preterm delivery before 34 weeks of gestation. S-relaxin was dichotomised to obtain best possible fit and then entered into the model. The same analyses were done for delivery within three days. Results Median S-relaxin levels varied significantly in the women with preterm prelabour rupture of membranes (PPROM) (316 pg/mL), contractions (222 pg/mL) or ripe cervices (203 pg/mL) ( P < 0.05). S-relaxin above the 80th centile ( ! 300 pg/mL) was associated with an increased risk of preterm delivery [crude OR ¼ 4.8; (95% CI: 1.9 -12)]. Likelihood ratio of a positive test is 2.6 (1.5 -4.9) and S-relaxin resulted in a post-test probability of preterm delivery of 0.72, compared with a pre-test probability of 0.49. S-relaxin contributed to the identification of delivery within three days [adj. OR ¼ 11 (95% CI: 1.8 -64)]. Conclusion S-relaxin may be a useful predictor in women with symptoms of delivery before 34 weeks of gestation.

Screening to prevent spontaneous preterm birth: systematic reviews of accuracy and effectiveness literature with economic modelling

“…177 One study evaluated the test's serial testing accuracy in predicting spontaneous preterm birth in asymptomatic women. 173 Appendix 5, Table 81 summarises each study's salient features.…”

“…26-8.31) and LR-of 0.861 (95% CI 0.38-1.96) and before 37 weeks' gestation it had LR+ of 0.80 (95% CI 0.19-3.31) and LR-of 1.07 (95% CI 0.72-1.57) Figure 29. 177 These LRs were used in decision-analytic modelling because they represented the largest higher-quality study for this reference standard. Individual accuracy results for symptomatic women can be found in Appendix 5, …”

Prognostic possibilities of relaxin as a marker of preterm birth

“…Ряд работ показал, что при одноплодной беременности высокий уровень релаксина значимо ассоциирован с прежде-временными родами [34,35], но имеется огра-ниченное число исследований по определению связи релаксина с преждевременными родами при многоплодии. При этом клинико-экспери-ментальные исследования R.J. Bell, B. Sutton, L.W.…”

“…В 1997 г. D. Platek, C. Chazotte, B. Girz et al провели работу по определению содержания релаксина у 28 бере-менных двойней и пришли к выводу, что увели-чение уровня сывороточного релаксина больше двух стандартных отклонений выше среднего (≥ 1,4 нг/мл) в ≤ 32 недели гестации является высокочувствительным и специфичным про-гностическим критерием преждевременных ро-дов при сроках более 35 недель [34,36]. В другой работе (2001) авторы также продемонстрирова-ли (n = 188), что в 24 недели гестации уровень релаксина > 90-го процентиля достоверно ассо-циирован с преждевременными родами.…”

Relaxin augments the inflammatory IL6 response in the choriodecidua

“…Elevated systemic relaxin H2 (RLN2, hereafter referred to as relaxin or RLN) levels, originating from the corpus luteum, have been associated with PTB [12]. Thus, in patients with more than one corpus luteum, as in some twin gestations [13], or in superovulation [14], the higher than normal systemic RLN somehow contributes to PTB, although the mechanism involved is currently unknown.…”