Preterm Labor

Backgrounds: Preterm birth refers to a delivery that occurs before 37 weeks and is relatively common, occurring in 5 to 18 percent of births worldwide .Material and method: Ideally, identification of modifiable and nonmodifiable risk factors for PTB before conception or early in pregnancy will lead to interventions that help prevent this complication. However, few interventions have been proven to prolong pregnancy in women at risk. This goal has been elusive for several reasons: two-thirds of PTBs occur among women with no risk factors, causality has been difficult to prove.Result: Early signs and symptoms of labor are nonspecific and include: menstrual-like cramping; mild, irregular contractions; low back ache; pressure sensation in the vagina; vaginal discharge of mucus, which may be clear, pink, or slightly bloody (ie, mucus plug, bloody show). The diagnosis of preterm labor is based on clinical criteria of regular painful uterine contractions accompanied by cervical dilation and/or effacement. Uterine contractions (≥4 every 20 minutes or ≥8 in 60 minutes) and Cervical dilation ≥3 cm or Cervical length <20 mm on transvaginal ultrasound or Cervical length 20 to <30 mm on transvaginal ultrasound and positive fetal fibronectin (fFN).Conclusion: For women with a history of sPTB, progesterone supplementation reduces the risk of recurrent sPTB by approximately 30 percent. Short cervical length on transvaginal ultrasound examination between 18 and 24 weeks of gestation in the current pregnancy is a risk factor for PTB and is the basis for screening for a short cervix in the midtrimester. For women with no previous history of sPTB who develop a short cervix, progesterone supplementation may prolong gestation. For women with a history of sPTB who develop a short cervix despite progesterone supplementation, placement of a cerclage may prolong gestation Interventions that have general health benefits and may reduce risk of PTB include smoking cessation, treatment of drug misuse, treatment of asymptomatic bacteriuria, and maintenance of a normal body mass index. Avoiding an interpregnancy interval of less than six months, and ideally less than 12 months, may reduce a woman's risk for sPTB. Singleton gestations are less likely to deliver preterm than multiple gestations. Prevention and reduction of multifetal gestations, particularly high-order multifetal gestations, can reduce the risk of preterm birth. No biomarker performs well as a screening test for predicting spontaneous preterm birth in asymptomatic low risk women.