N-Acetyl Cysteine for Prevention of Preterm Birth
Condition: Preterm Labour
MeSH terms: Premature Birth; Obstetric Labor, Premature
Study type: Interventional
Phase: Phase 4

Summary: 
      The antioxidant effect of N-Acetyl cysteine can abort the inflammatory cascade responsible
      for initiation of preterm labour especially among patients with reccurent preterm birth and
      patients having bacterial vaginosis
    

Detailed description: 
      Patients who attend the antenatal care clinic at Assiut University Hospital were recruited
      and counseled about participating in the study. A written informed consent was taken.
      Patients had the right to refuse to participate and/or withdraw from the study at ay time
      without being denied their regular full clinical care. Personal information as well as data
      collected were subjected to confidentiality and were not made available to third party.

      Gestational age was determined on the basis of the last menstrual period, confirmed by an
      ultrasound between 14 weeks and 20 weeks gestation and calculated in menstrual weeks.
      Patients were included when they were pregnant +/- 28 to 32 weeks, having a documented
      history of at least one preterm labour in the previous pregnancy and having no uterine
      contractions at the time of the study. Patients were excluded if they refused to participate
      in the study, had prelabour premature rupture of membranes (PPROM), had an incompetent
      cervical os proved by funneling of the internal os on ultrasound examination or by a
      documented history with or without a cercelage done in the previous or current pregnancy.
      Patients with twin pregnancy, intrauterine foetal death, malpresentations, known fetal
      anomaly, progesterone or heparin treatment during the current pregnancy, hypertension
      requiring medication, a seizure disorder, Irregular and/or unsure menstrual dates or abortion
      within 3 months prior to the last menses were also excluded.

      Clinical work-up included history taking, examination, obstetric ultrasound evaluation and
      Bio physical profile (BPP). All Patients were empirically treated for bacterial vaginosis
      prior to enrollment into one of the study groups by giving them oral metronidazole 250 mgm 3
      times/day for one week. After ending one course of the treatment all patients were subjected
      to a vaginal swab to exclude bacterial vaginosis. Criteria used for diagnosing BV were those
      of Amsel et al., 1983 by finding at least three of the four following criteria: 1) thin, dark
      or dull gray, homogenous, malodorous discharge that adheres to the vaginal wall; 2) elevated
      vaginal pH of greater than 4.5; 3) positive whiff/amine test, and 4) presence of clue cells
      on wet-mount microscopic evaluation.

      Patients with free samples were included in the study. Patients who proved an active or mixed
      infection were treated accordingly and excluded from the study. Patients were randomly
      allocated to two treatment groups. Group one, control group: given hydroxyl progesterone
      caproate (150mgm) every 3 days starting from the 28th week of pregnancy till completed 36
      weeks of gestation. Group two patients were given hydroxyl progesterone caproate (150mgm)
      weekly injections plus NAC 0.6 gm (Sedico, Egypt) orally daily starting from the 28th week of
      pregnancy till delivery or completed 36th week of pregnancy. Patients were followed up by
      routine 2 week antenatal clinic visits for the occurrence of uterine contractions, their
      frequency, intensity and need for seeking medical advise. NAC or 17 hydroxyl progesterone
      caproate treatment was discontinued in both groups only if patient either completed 36 weeks
      or entered actively into labour (at least three uterine contractions, 40 seconds each,
      reaching 50 mmHg on external tocodynamometer monitoring and/or associated with progressive
      cervical dilatation reaching 5 cms and/or occurrence of rupture of membranes). Once
      established labour, a second vaginal swab was taken and subjected to microscopical
      examination and amine test to rule out newly developed BV. Outcomes included occurrence of
      contractions, prolongation of pregnancy, neonatal outcome in both groups.

      Sample size:

      Sample size was based on the findings of Iams et al., who found a high incidence of recurrent
      PTL among women who had positive findings with infection (64%). A reduction in incidence of
      PTL of 30% was considered acceptable. Sample size was calculated on a basis of 95% confidence
      interval, 80% power and 49 patients were needed in each arm.
    

Intervention name(s): acetylcysteine in arm 1
Intervention type(s): Drug
Intervention description(s): Arm 2, control group: given hydroxyl progesterone caproate (150mgm) every 3 days starting from the 28th week of pregnancy till completed 36 weeks of gestation.
Arm 1 patients were given hydroxyl progesterone caproate (150mgm) weekly injections plus NAC 0.6 gm (Sedico, Egypt) orally daily starting from the 28th week of pregnancy till delivery or completed 36th week of pregnancy.
Intervention MeSH terms: Acetylcysteine; N-monoacetylcystine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: preterm labour; n acetyl cysteine; bacterial vaginosis