Background Smoking is a modifiable lifestyle factor that has been shown to be associated with adverse perinatal outcomes and to have adverse health and dose-dependent connective tissue effects. The objective of this study was to examine whether smoking during pregnancy was associated with the incidence of obstetric anal sphincter injuries (OASIS) among six birthweight groups in singleton vaginal deliveries, considering nulliparous and multiparous women separately between 1997 and 2007 in Finland. Methodology A retrospective population-based register study. Populations included women with spontaneous singleton vaginal deliveries, consisting of all 213,059 nulliparous and all 288,391 multiparous women. Incidence of OASIS (n = 2,787) between smoking status groups was adjusted using logistic regression analyses. Principal Findings Of the nulliparous women, 13.1% were smokers, 3.6% had given up smoking during the first trimester of their pregnancy and 81.1% were non-smokers. Among these groups 0.7%, 0.9% and 1.1%, respectively suffered OASIS (p≤0.001). Nulliparous women who smoked had a 28% (95% CI 16–38%, p≤0.001) lower risk of OASIS compared to non-smokers, when adjusting for background variables. In multiparous women, the overall frequencies of OASIS were much lower (0.0–0.2%). A similar inverse relationship between OASIS rates and smoking was significant in pooled univariate analysis of multiparous women, but multivariate analysis revealed statistically insignificant results between non-smokers and smokers. Conclusions Nulliparous women who were smokers had a 28% lower incidence of OASIS. However, smoking during pregnancy cannot be recommended since it has shown to be associated with other adverse pregnancy outcomes and adverse health effects. The observed association warrants clinical repetition studies and, if confirmed, also in vitro studies focusing on connective tissue properties at a molecular and cellular level.
References
[1]
Millar J, Mattke S, the Members of the OECD Patient Safety Panel (2004) Selection Indicators for Patient Safety at Health System Level in OECD countries. Accessed 29 May 2012.
[2]
Nordisk Ministerr？d (2010) Nordisk kvalitetsm？ling i sundhedsv？senet. Nordisk Ministerr？d. 256 p.
[3]
Sultan A (1999) Obstetric perineal injury and anal incontinence. Clinical Risk 5: 193–196.
[4]
Dudding TC, Vaizey CJ, Kamm MA (2008) Obstetric anal sphincter injury: incidence, risk factors, and management. Ann Surg 247(2): 224–237.
[5]
EURO-PERISTAT Project (2008) EUROPEAN PERINATAL HEALTH REPORT. Accessed on 2012 Jun 22.
[6]
Frankman EA, Wang L, Bunker CH, Lowder JL (2009) Episiotomy in the United States: has anything changed? Am J Obstet Gynecol 200(5): 573.e1–573.e7.
[7]
Power D, Fitzpatrick M, O’Herlihy C (2006) Obstetric anal sphincter injury: how to avoid, how to repair: a literature review. J Fam Pract 55(3): 193–200.
[8]
Pearse WH (1963) Electronic recording of forceps delivery. Am J Obstet Gynecol 86: 43–51.
[9]
Carroli G, Mignini L (2009) Episiotomy for vaginal birth. Cochrane Database Syst Rev. CD000081 p.
[10]
Mendelsohn C (2011) Women who smoke - A review of the evidence. Aust Fam Physician 40(6): 403–407.
[11]
Green AC, Hughes MC, McBride P, Fourtanier A (2011) Factors associated with premature skin aging (photoaging) before the age of 55: a population-based study. Dermatology 222(1): 74–80.
[12]
Ward KD, Klesges RC (2001) A meta-analysis of the effects of cigarette smoking on bone mineral density. Calcif Tissue Int 68(5): 259–270.
[13]
Kanis JA, Johnell O, Oden A, Johansson H, De Laet C, et al. (2005) Smoking and fracture risk: a meta-analysis. Osteoporos Int 16(2): 155–162.
[14]
Torrungruang K, Gongsakdi V, Laohaviraphab L, Likittanasombat K, Ratanachaiwong W (2012) Association between cigarette smoking and the intraoral distribution of periodontal disease in Thai men over 50 years of age. J Investig Clin Dent 3(2): 135–141.
[15]
Mehendale R, Hibbard J, Fazleabas A, Leach R (2007) Placental angiogenesis markers sFlt-1 and PlGF: response to cigarette smoke. Am J Obstet Gynecol 197(4): 363.e1–363.e5.
[16]
Bulmanski Z, Brady M, Stoute D, Lallier TE (2011) Cigarette Smoke Extract Induces Select MMP and Integrin Expression in Periodontal Ligament Fibroblasts. J Periodontol. In press.
[17]
Schaffer JI, Wai CY, Boreham MK (2005) Etiology of pelvic organ prolapse. Clin Obstet Gynecol 48(3): 639–647.
[18]
Kim CM, Jeon MJ, Chung DJ, Kim SK, Kim JW, et al. (2007) Risk factors for pelvic organ prolapse. Int J Gynaecol Obstet 98(3): 248–251.
[19]
Hannestad YS, Rortveit G, Daltveit AK, Hunskaar S (2003) Are smoking and other lifestyle factors associated with female urinary incontinence? The Norwegian EPINCONT Study. BJOG 110(3): 247–254.
[20]
Tahtinen RM, Auvinen A, Cartwright R, Johnson TM 2nd, Tammela TL, et al (2011) Smoking and bladder symptoms in women. Obstet Gynecol 118(3): 643–648.
[21]
Olsen AL, Smith VJ, Bergstrom JO, Colling JC, Clark AL (1997) Epidemiology of surgically managed pelvic organ prolapse and urinary incontinence. Obstet Gynecol 89(4): 501–506.
[22]
Baghestan E, Irgens LM, Bordahl PE, Rasmussen S (2010) Trends in risk factors for obstetric anal sphincter injuries in norway. Obstet Gynecol 116(1): 25–34.
[23]
Christianson LM, Bovbjerg VE, McDavitt EC, Hullfish KL (2003) Risk factors for perineal injury during delivery. Am J Obstet Gynecol 189(1): 255–260.
[24]
Hudelist G, Gelle’n J, Singer C, Ruecklinger E, Czerwenka K, et al. (2007) Factors predicting severe perineal trauma during childbirth: role of forceps delivery routinely combined with mediolateral episiotomy. Am J Obstet Gynecol 192(3): 875–881.
[25]
Lowder JL, Burrows LJ, Krohn, Weber AM (2007) Risk factors for primary and subsequent anal sphincter lacerations: a comparison of cohorts by parity and prior mode of delivery. Am J Obstet Gynecol 196(4): 344–345.
[26]
Lewis C, Williams AM, Rogers RG (2008) Postpartum anal sphincter lacerations in a population with minimal exposure to episiotomy and operative vaginal delivery. Int Urogynecol J Pelvic Floor Dysfunct 19(1): 41–45.
[27]
Raisanen S, Vehvilainen-Julkunen K, Gissler M, Heinonen S (2011) High episiotomy rate protects from obstetric anal sphincter ruptures: A birth register-study on delivery intervention policies in Finland. Scand J Public Health 39(5): 457–463.
[28]
Raisanen SH, Vehvilainen-Julkunen K, Gissler M, Heinonen S (2009) Lateral episiotomy protects primiparous but not multiparous women from obstetric anal sphincter rupture. Acta Obstet Gynecol Scand 88(12): 1365–1372.
[29]
Raatikainen K, Huurinainen P, Heinonen S (2007) Smoking in early gestation or through pregnancy: a decision crucial to pregnancy outcome. Prev Med 44(1): 59–63.
[30]
Kalis V, Laine K, de Leeuw J, Ismail K, Tincello D (2012) Classification of episiotomy: towards a standardisation of terminology. BJOG 119(5): 522–526.
[31]
de Leeuw JW, Struijk PC, Vierhout ME, Wallenburg HC (2001) Risk factors for third degree perineal ruptures during delivery. BJOG 108(4): 383–387.
[32]
Hackshaw A, Rodeck C, Boniface S (2011) Maternal smoking in pregnancy and birth defects: a systematic review based on 173 687 malformed cases and 11.7 million controls. Hum Reprod Update 17(5): 589–604.
[33]
Bernhard D, Moser C, Backovic A, Wick G (2007) Cigarette smoke–an aging accelerator? Exp Gerontol 42(3): 160–165.
[34]
Laine K, Gissler M, Pirhonen J (2009) Changing incidence of anal sphincter tears in four Nordic countries through the last decades. Eur J Obstet Gynecol Reprod Biol 146(1): 71–75.
[35]
Gissler M, Teperi J, Hemminki E, Merilainen J (1995) Data quality after restructuring a national medical registry. Scand J Soc Med 23(1): 75–80.
[36]
Jaakkola N, Jaakkola MS, Gissler M, Jaakkola JJ (2001) Smoking during pregnancy in Finland: determinants and trends, 1987–1997. Am J Public Health 91(2): 284–286.
[37]
Keskim？ki I, Aro S (1991) Accuracy of data on diagnoses, procedures and accidents in the Finnish Hospital Discharge Register. IJHS 2: 15–21.
