Phosphorylated IGFBP-1 in predicting successful vaginal delivery in post-term pregnancy

A randomized clinical trial of Premaquick biomarkers versus transvaginal cervical length for pre-induction cervical assessment at term among pregnant women

Objectives

To compare Premaquick biomarkers (combined insulin-like growth-factor binding protein 1 and interleukin-6) and cervical length measurement via transvaginal ultrasound for pre-induction cervical evaluation at term among pregnant women.

Methods

A randomized clinical trial of consenting pregnant women at the Nnamdi Azikiwe University Teaching Hospital, Nnewi, Nigeria. The women were randomized equally into Premaquick group (n = 36) and transvaginal ultrasound group (n = 36). The cervix was adjudged 'ripe' if the Premaquick test was positive or if the trans-vaginal measured cervical length was less than 28 mm. The primary outcome measures were the proportions of women who needed prostaglandin analogue for cervical ripening and the proportion that achieved vaginal delivery after induction of labour. The trial was registered in Pan African clinical trial registry (PACTR) registry with approval number PACTR202001579275333.

Results

The baseline characteristics were similar between the two groups (p > 0.05). There was no statistically significant difference between the two groups in terms of proportion of women that required prostaglandins for pre-induction cervical ripening (41.7 versus 47.2%, p = 0.427), vaginal delivery (77.8 versus 80.6%, p = 0.783), mean induction to delivery interval (22.9 ± 2.81 h versus 24.04 ± 3.20 h, p = 0.211), caesarean delivery (22.2 versus 19.4%, p = 0.783), proportion of neonate with birth asphyxia (8.30 versus 8.30%, p = 1.00) and proportion of neonate admitted into special care baby unit (16.7 versus 13.9%, p = 0.872). Subgroup analysis of participants with 'ripe' cervix at initial pre-induction assessment showed that the mean induction to active phase of labour interval and mean induction to delivery interval were significantly shorter in Premaquick than transvaginal ultrasound group.

Conclusion

Pre-induction cervical assessment at term with either Premaquick biomarkers or transvaginal ultrasound for cervical length is effective, objective and safe with similar and comparable outcome. However, when compared with women with positive transvaginal ultrasound at initial assessment, women with positive Premaquick test at initial assessment showed a significantly shorter duration of onset of active phase of labour and delivery of baby following induction of labour.

Serum Melatonin as a Biomarker for Assessment of Late-term and Postterm Pregnancies in Women without Spontaneous Onset of Labor

We conducted a prospective study to assess serum melatonin as a biomarker to predict the development of late-term and postterm pregnancies and spontaneous beginning of labor in women with term pregnancies. Population of this prospective study included pregnant women with late-term and postterm pregnancies and term pregnancies as controls. In these study groups, serum melatonin concentrations were measured in women with or without labor and their perinatal data were collected. In the postterm pregnancies without labor, the lowest median melatonin concentrations were measured (p<0.05). In the late-term and postterm pregnancies with and without labor, the median serum melatonin concentrations were significantly lower than term ones (p<0.05). In the term pregnancies with labor, the highest median melatonin concentration was measured (p<0.05). A serum melatonin concentration≤34 pg/mL as a cut-off value determines late-term and postterm pregnancy with a sensitivity of 80.4% and a specificity of 81.4%. A serum melatonin concentration>29.35 pg/mL as a cut-off value determines presence of labor with a sensitivity of 82.1% and a specificity of 55.0%. In women with term pregnancies, with the measurement of serum melatonin, it is possible to predict the development of late-term and postterm pregnancies and whether these pregnancies undergo spontaneous labor. With further studies, these findings need to be supported before their routine clinical use.

Role of Cervical Phosphorylated Insulin-Like Growth Factor-Binding Protein 1 (phIGFBP1) for Prediction of Successful Induction Among Primigravida with Prolonged Pregnancy

Purpose of the Study

To estimate and to compare the levels of cervical phIGFBP-1 among primigravida with prolonged pregnancy, with and without successful induction of labor (IOL).

Methods

A diagnostic study (cross-sectional study design) was conducted in our institution from November 2016 to April 2018 on 84 primigravida at ≥ 41 weeks with uncomplicated singleton pregnancy. The results were analyzed using SPSS software and receiver operating characteristics curves to determine the best cutoff using Youden Index. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive (+ LR) and negative likelihood ratio (- LR) were calculated. P value < 0.05 was considered significant. Logistic regression analysis was used to determine the predictive ability of the three markers for successful IOL.

Results

The cutoff level of phIGFBP-1, Bishop score (BS) and transvaginal cervical length (TVL) were 7.8 µg/l, 3 and 3.5 cm, respectively. The sensitivity, specificity, PPV, NPV, + LR and - LR of phIGFBP-1 (> 7.8 µg/l) were 0.87, 0.87, 0.89, 0.85, 6.76 and 0.15, respectively. Using logistic regression analysis, phIGFBP-1 was found to be the best predictor of successful IOL (OR 44.200; 95% CI 12.378-157.831, p < 0.001).

Conclusion

phIGFBP-1 is a strong independent predictor successful IOL as compared to TVL and BS in primigravida with prolonged pregnancy.

Cervical biomarkers as predictors of successful induction of labour by Foley catheter

The prediction of successful labour induction is difficult, indicating a need for a biomarker test. Little is known about the effect of Foley catheter (FC) induction on biochemical mediators in the cervix, such as the insulin-like growth factor binding protein-1 (IGFBP-1), matrix metalloproteinases (MMP) and their inhibitors (TIMP). We enrolled 35 nulliparous women with singleton pregnancies, intact amniotic membranes and cephalic presentation ≥40 gestational weeks scheduled for labour induction by FC. Serial cervical swab samples were collected at FC insertion and expulsion. The concentrations of IGFBP-1, PhIGFBP-1, MMP-8, MMP-2, MMP-9, TIMP-1 and TIMP-2 were analysed. The IGFBP-1 and phIGFBP-1 concentrations increased during the FC-induced cervical ripening. In contrast, MMP-8 and MMP-9 concentrations decreased. However, these changes did not predict the outcome of the labour induction, thus appearing not suitable for clinical use. Impact statement What is already known on this subject? During cervical ripening, various constituents interact in a complex network. Insulin-like growth factor binding protein-1 (IGFBP-1), matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) appear to play a role in cervical ripening. The mechanism of Foley catheter on cervical ripening consists of direct mechanical stretching of the cervix and lower uterine segment, and the stimulation of local secretion of endogenous prostaglandins. What do the results of this study add? This study investigated the role of cervical biochemical mediators during Foley catheter-induced cervical ripening, and their predictive value in a successful labour induction and vaginal delivery. The IGFBP-1 and phosphorylated IGFBP-1 concentrations increased, whereas MMP-8 and MMP-9 concentrations decreased during the Foley catheter-induced cervical ripening in nulliparous women. However, these changes did not predict the outcome of labour induction, thus appearing not suitable for clinical use. What are the implications of these findings for clinical practice and/or further research? Prediction of a successful labour induction is difficult, indicating a need for a biomarker test. Future studies with larger data are needed for investigating the role of these cervical biomarkers in successful labour induction, and in developing a future bedside a screening tool for clinical use.

Enhanced expression of transient receptor potential channel 3 in uterine smooth muscle tissues of lipopolysaccharide-induced preterm delivery mice

OBJECTIVES

We aimed to investigate the influence of transient receptor potential channel 3 (TRPC3) on lipopolysaccharide-induced (LPS) preterm delivery mice.

MATERIALS AND METHODS

Mice were randomly assigned to the four groups: an unpregnant group, a mid-pregnancy group (E15), a term delivery group, and an LPS-induced preterm delivery group (intraperitoneal injection LPS at 15 days). Uterine smooth muscles were obtained through caesarean section; TRPC3 expression was measured by real-time PCR, western blotting, and immunohistochemistry. A specific inhibitor of TRPC3 (SKF96365) was injected into the LPS-induced preterm delivery group to determine whether the delivery interval was prolonged.

RESULTS

TRPC3 was primarily expressed in the uterine smooth muscle layer. In addition, the LPS-induced preterm delivery group had an obviously higher expression level of TRPC3 mRNA and protein compared with the unpregnant and E15 groups, which were close to term delivery. More importantly, SKF96365 prolongs the delivery interval of LPS-induced preterm delivery mice.

CONCLUSION

Enhanced expression of TRPC3 may be associated with LPS-induced preterm delivery in mice. The specific inhibitor of TRPC3 (SKF96365) may be helpful for clinical treatment of preterm delivery.