DOI: http://dx.doi.org/10.18203/2320-1770.ijrcog20184473

Evolution of second trimester low implanted placenta to previa at term: a prospective cohort study

Omar M. Shaaban, Hamdy A. Ahmed, Mohammed K. Ali, Ahmed M. Abbas, Ahmed Nasr, Ahmed M. Makhlouf

Abstract


Background: The objective of this study is to identify the percentage of low implanted placenta (LIP) at second trimester of pregnancy and identify the risk factors of its persistence to placenta previa (PP) at term.

Methods: Through a registered prospective cohort study conducted at tertiary hospital in Upper Egypt, authors screened all pregnant ladies comes to present facility for antenatal second trimester USG between 18-24 weeks gestation. All participants interviewed for detailed risk factors of placenta previa. Those diagnosed to have a LIP (≤1.5 cm from the internal os) had had TVS to confirm the exact distance between the lower edge of the placenta and the internal os. Serial USG had been done every 4 weeks up to delivery to measure the same distance. The primary outcome was the percentage of LIP at 18-24 weeks. Logistic regression analysis was performed to predict the risk factors for PP at term.

Results: Through screening of 1000 pregnant lady, LIP had been identified in (52 cases) 5.2% of pregnant women between 18-24 weeks. This percentage dropped gradually to reach 1.3% at 36 weeks of gestation and at time of delivery. The logistic regression analysis demonstrated that the distance between the internal os and the lower edge of the placenta between 18-24 weeks was the single significant variable associated with PP at term (p<0.001, odds ratio 0.319, 95% CI 0.20-0.50). However, excluding the distance from the regression model demonstrated other risk factors as previous miscarriage, previous cesarean section (CS), and history of multiple pregnancies and history of previous PP.

Conclusions: About 5.0% of pregnant women have LIP at the second trimester of pregnancy (18-24 weeks) and only 25.0 % of them remain placenta previa at term. A cut-off value of 10 mm between the internal os and the lower edge of the placenta is the most important predictor of development of PP.


Keywords


Low implanted placenta, Placenta previa, Ultrasound

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References


Royal College of Obstetricians and Gynaecologists. Placenta praevia, placenta praevia accreta and vasa praevia: diagnosis and management. Green-top Guideline No. 27. London: RCOG; 2011.

Umazume T, Hayasaka S, Kato F, Ishikawa S, Morikawa M, Minakami H. Sudden maternal hypoxemia during elective cesarean section in a woman with placenta previa. Clin Case Rep. 2017;5(10):1668-71.

Kollmann M, Gaulhofer J, Lang U, Klaritsch P. Placenta praevia: incidence, risk factors and outcome. J Matern Fetal Neonatal Med. 2016;29(9):1395-8.

Betrán AP, Ye J, Moller AB, Zhang J, Gülmezoglu AM, Torloni MR. The increasing trend in caesarean section rates: global, regional and national estimates: 1990-2014. PloS One. 2016;11(2):e0148343.

Royal College of Obstetricians and Gynaecologists. Placenta Praevia, Placenta Praevia Accreta and Vasa Praevia: Diagnosis and Management. Green-top Guideline No.27. London: RCOG; 2011.

Rosenberg T, Pariente G, Sergienko R, Wiznitzer A, Sheiner E. Critical analysis of risk factors and outcome of placenta previa. Arch Gynecol Obstet. 2011;284(1):47-51.

Sekiguchi A, Nakai A, Kawabata I, Hayashi M, Takeshita T. Type and location of placenta previa affect preterm delivery risk related to antepartum hemorrhage. Int J Med Sci. 2013;10(12):1683-8.

Bhide A, Thilaganathan B. Recent advances in the management of placenta previa. Curr Opin Obstet Gynecol. 2004;16(6):447-51.

Reddy UM, Abuhamad AZ, Levine D, Saade GR. Fetal imaging: executive summary. Obstet Gynecol. 2014;123:1070-82.

Eichelberger KY, Haeri S, Kessler DC, Swartz A, Herring A, Wolfe HM. Placenta previa in the second trimester: sonographic and clinical factors associated with its resolution. Am J Perinatol. 2011;28:735-40.

Lauria MR, Smith RS, Treadwell MC, Comstock CH, Kirk JS, Lee W, et al. The use of second-trimester transvaginal sonography to predict placenta previa. Ultrasound Obstet Gynecol. 1996;8(5):337-40.

Durst JK, Tuuli MG, Temming LA, Hamilton O, Dicke JM. Resolution of a low-lying placenta and placenta previa diagnosed at the mid trimester anatomy scan. J Ultrasound Med. 2018.

SOGC clinical practice guideline. Diagnosis and Management of Placenta Previa. No. 189, March 2007.

Macdonald AA, Fowden AL. Microscopic anatomy of the ungulate placenta. Equine Vet J Suppl. 1997;24:7-13.

Mustafa SA, Brizot ML, Carvalho MH, Watanabe L, Kahhale S, Zugaib M. Transvaginal ultrasonography in predicting Placenta previa at delivery: a longitudinal study. Ultrasound Obstet Gynecol. 2002;20:356-9.

Daskalakis G, Simou M, Zacharakis D, Detorakis S, Akrivos N, Papantoniou N, et al. Impact of placenta previa on obstetric outcome. Int J Gynaecol Obstet. 2011;114:238-41.

Rosati P, Guariglia L. Clinical significance of placenta previa detected at early routine transvaginal scan. J Ultrasound Med. 2000;19(8):581-5.

Shukunami K, Nishijima K, Kurodawa T, Tajima K, Kamitani N, Yoshida Y, et al. A small-angled thin edge of the placenta predicts abnormal placenation at delivery. J Ultrasound Med. 2005;24:331-5.

Becker RH, Vonk R, Mende BC. The relevance of placental location at 20-23 gestational weeks for prediction of Placenta previa at delivery: evaluation of 8650 cases. Ultrasound Obstet Gynecol. 2001;17:496-501.

Bhide A, Prefumo F, Moore J, Hollis B, Thilaganathan B. Placental edge to internal os distance in the late third trimester and mode of delivery in placenta praevia. BJOG. 2003;110(9):860-4.

Obata S, Ishiharak. Ultrasonographic study and low-lying placenta and it's clinical significance. Nippon Sanka Fujinka Gakkai Zasshi. 1993;45:1115-8.

Omokanye LO, Olatinwo AW, Salaudeen AG, Ajiboye AD, Durowade KA. A 5-year review of pattern of placenta previa in Ilorin, Nigeria. Int J Health Sci. 2017;11(2):35.

Kollmann M, Gaulhofer J, Lang U, Klaritsch P. Placenta praevia: incidence, risk factors and outcome. Ultrasound Med-Eur J Ultrasound. 2013;34(S 01):WS_SL6_01.

Fidan U, Ulubay M, Bodur S, FerdiKinci M, EmreKaraşahiN K, Cemal Yenen M. The effect of anatomical placental location on the third stage of labor. Clin Anat. 2017;30(4):508-11.

Kacey E, Honor M, Anthony S, Dave K, Amy H. Second trimester placenta previa and resolution patterns: a four year institutional review. JOG. 2009;201(6):135.

Taipale P, Hiilesmaa V, Ylostalo P. Diagnosis of Placenta previa by transvaginal sonographic screening at 12-16 weeks in a non-selected population. Obstet Gynecol. 1997;89:364-7.