Vaginal Progesterone versus Cervical Cerclage to Prevent Preterm Birth

INTRODUCTION

Preterm birth (PTB), defined as birth before the 37th week of pregnancy, is a serious perinatal health issue. It is implicated in 75 percent of prenatal deaths and more than half of long-term neurological impairments, and it is the second most common cause of death in children under the age of five.¹ Preterm births are on the rise in many countries across the world, and they have become a global health concern that is expected to skyrocket over the next decade. ² The increasing rise in preterm births is concerning, as more than 1 million infants die each year as a result of problems caused by premature delivery.³

Various treatments have been identified as having a possible role in reducing the likelihood of repeated preterm birth (PTB). ⁴

Bed rest and vaginal progesterone have been tried to ease this bothersome condition, but only cerclage has been proven to enhance the mechanical and functional length of the cervix, thereby contributing to the reduction of PTB. Cervical shortening alone or in twin gestation with or without a short cervix, excluding instances with an associated cervical length (CL) of less than 15 mm and/or cervical dilatation more than 10 mm, cerclage is not acceptable for all therapeutic situations. ⁵

Progesterone concentrations in the bloodstream rise throughout pregnancy: It is, without a doubt, an important component of pregnancy maintenance. One of the primary mechanisms of progesterone activity in maintaining pregnancy is the cessation of myometrial contractions, which is ascribed to progesterone's relaxant effect on myometrial strips. ⁶

Therefore, the aim of this study was to compare the efficacy of vaginal progesterone and cerclage in preventing preterm birth.

PATIENTS AND METHODS

This study was a prospective cohort randomized clinical study that was conducted on 120 pregnant females with singleton gestation from12-16 weeks. They were at high risk of PTB as those with history of prior spontaneous preterm labor, sonographic cervical length less than 25 mm in mid trimester or women with certain abnormalities of the uterus for instance, septate, unicornate, or bicornate uteri. They were divided into: 60 cases that were prescribed vaginal progesterone (400mg daily at night from the 16^th week till rupture of membranes or delivery) and the remaining 60 cases underwent cervical cerclage. They were all recruited from the outpatient clinics at Al -Hussien university Hospital and Kafr EL- Sheikh General Hospital during the period from March 2020 till December 2020.Written consents were obtained from the patients.

Exclusion criteria: Multiple gestations, fetal chromosomal anomalies, intrauterine growth restriction, any fetal infection, and women who were already receiving an intervention before randomization to our interventions of interest were all excluded from this study.

The elected patients were subjected to detailed history taking, complete general, abdominal examination and ultrasonographic examination using a 3.5- 5-MHz transabdominal probe. After voiding, transvaginal scan was performed to measure the cervical length that was assessed by a 5-9 MHz transvaginal probe. Then group I received vaginal progesterone from the 16th week till rupture of membranes or delivery, and Group underwent cervical cerclage (McDonald operation)

A purse string stitch was used to cinch the cervix shut; the cervix stitching involved a band of suture at the upper part of the cervix followed by post-operative antibiotics. The stitch was generally removed around the 37^th week of gestation or earlier if needed.

Then after intervention cases were followed up till parturition through routine antenatal care and any case developed IUGR were excluded from this study. Serial transabdominal ultrasound examinations were done to monitor AFI and fetus growth

All women received antenatal corticosteroids (Dexamethasone 6mg bidaily for 48 hours) before 36 weeks of gestation. The primary outcome was cases that completed 37 weeks of gestation in both groups.

Statistical analysis: Statistical analyses of data were done utilizing SPSS version 23. Shapiro –Wilks test was used to test normal distribution of variables. Numerical data were expressed as mean ± standard deviation or median and range. Categorical data were summarized as percentages. The significance for the difference between groups was determined by using two-tailed Student’s t test. Also Qualitative variables were assessed by chi-squared χ2test. The probability (P) values of ≤0.05 were considered statistically significant indicated. Mann whitney test was used to compare data that were not normally distributed.

RESULTS

Overall, 120 pregnant women at high risk of preterm birth who were chosen from the outpatient clinics at Al -Hussien university hospital and Kafr EL- Sheikh General hospital during the period of research from March 2020 to December 2020. They all had singleton pregnancy with gestational age at the first antenatal visit of 12-16 weeks. Additionally, they had history of previous spontaneous preterm labor, and they all presented with sonographic cervical length

The mean age was 26.07 ± 3.7 years in group (I) and 26.46 ± 3.6 years in group (II). There were no statistically significant differences in the mean age of both studied groups (P=0.574). Also, these results indicated that there was no statistically significant difference between all studied groups according to body mass index, mean cervical length, and parity (P>0.05) (Table1).

Additionally, the present study showed that there was no statistically significant difference between the two studied groups regarding previous history of preterm prelabour rupture of membranes (PPROM), preterm labour, and abortion (P>0.05). The present study indicated that cerclage, compared with vaginal progesterone treatment, significantly increased the rates of cesarean delivery (75% versus 63.6%) but without significance difference (P=0.194). It was observed that the mean gestational age improved in the cerclage groups by about 3.92 days The gestational age at delivery was higher in the cerclage group (36.32±2.12 weeks) than that in the progesterone group (35.76±2.33 weeks), but without significant difference (P = 0.190).

Considering neonatal birth weight, it was 2185.9±314.2 in women who received vaginal progesterone compared to 2305.8±234.6 in women who underwent cerclage; with P=value =0.025. In women who received vaginal progesterone, 44 (80%) of newborns had weight less than 2.5 kg and remaining babies (20%) were more than 2.5 kg weight whereas 76.8% of newborns to women who underwent cerclage had weight less than 2.5 kg, and 23.2% were of weight more than 2.5 kg. The current study showed that there was no significant difference between distribution of studied groups regarding neonatal birth weight (P =0.681) (Table1).

As regard neonatal outcome of the current delivery, the overall morbidity was shown in 22 cases (19.8%) and mortality was 5 (4.5%). Causes of mortality was very low birth weight (

In addition, the mean Apgar score was higher in the cerclage group than that in the progesterone groups (7.79 vs. 7.72). This results showed that the difference in the Apgar score was not statistically significant between the progesterone and the cerclage groups (P = 0.809) (Table1).

Table 1: Demographic data and biochemical parameters of both studied groups.

Values are expressed as mean ± standard deviation or n (%) unless otherwise specified

BMI — body mass index

*: P ≤0.05, **: P ≤0.01.