Prevention of preterm labor by AIWA's score

Abstract

Purpose: To elucidate the availability of ‘AIWA’s scoring' in prevention of preterm labor.Patients: We retrospectively studied the 6434 deliveries after 22 weeks of gestation, managed at AIWA‐Maternity Hospital from 1986 to 1990, and from 1995 to 2000. • C‐stage: deliveries from 1986 to 1990: 1786 (control stage without AIWA's scoring); • P‐stage: deliveries from 1995 to 1997: 2190 (prototype stage without AIWA's scoring); • A‐stage: deliveries from 1998 to 2000: 2458 (applied stage with AIWA's scoring). Nine twins and seven cases of pregnant mother transportation (MT) in (C) 1786, 25 twins and 3 MT in (P) 2190, and 17 twins, 2 triplets, 6 MT in (A) 2458, were involved, respectively.Methods: The ‘AIWA’s score' of risk assessment for premature delivery consists of cervical consistency, insertion resistance to external os of uterus by internal examination, and cervical length and funneling of internal os of uterus measured by transvaginal ultrasonography. The full AIWA's score is 12 point, which means extremely high risk of premature labor. On the other hand, 0 point means no risk of it. Then, P‐score (0–3) consists of the history of early delivery, abortion after 18 weeks of gestation, present multiplicity and so forth. AIWA's score + P‐score = AP‐score. (A) From 1998 to 2000, in case with AP‐score >8, before 26 weeks of gestation, patients had cervical cerclage if they wanted after severely informed consent. We compared some parameters between C‐ and A‐stage.Results: The rate of premature delivery declined (from 4.5 to 3.2% <37 weeks [P < 0.05]; from 2.5 to 1.3%, <36 weeks [P < 0.01]) in A‐stage using the risk assessment system. In all premature deliveries, those before 32 weeks of gestation declined from 15.2 to 2.6% (P < 0.01) in A‐stage. The rate of preterm PROM <34 weeks in all deliveries declined from 0.56 to 0.12% (P < 0.05), while the rate of preterm PROM in premature labor decreased from 12.7 to 3.9%, and the rate of emergency cervical cerclage also decreased from 13.5 to 1.2% (P < 0.05). In single baby delivery, the rate of cervical cerclage slightly decreased from 1.1 to 0.75% in nulliparous mother, however, it extremely increased from 2.7 to 5.3% in multipara.Conclusions: Prevention of preterm labor by prophylactic cervical cerclage using ‘AIWA’s score' would be useful to decrease premature deliveries and eventually to relieve the shortage of NICU beds in Japan. Preterm PROM before 34 weeks of gestation has been a problem for long years in perinatal management. Also, the success rate of emergency cervical cerclage has been poor. The rate of those two problems would declined using AIWA's scoring system. The rate of cervical cerclage in multipara was two times higher than that in control stage. The future issues is making of more appropriate indication and contraindication of cervical cerclage with special reference to patients QOL.