Normal pregnancy
Screening for PP is not indicated in this population, even if other risk factors are present (with the exception of previous scarred uterus, prior PP, and IVF treatment). Prediction models combining risk factors for PP are too inefficient to be useful.[9]Odibo AO, Cahill AG, Stamilio DM, et al. Predicting placental abruption and previa in women with a previous cesarean delivery. Am J Perinatol. 2007 May;24(5):299-305.
http://www.ncbi.nlm.nih.gov/pubmed/17514600?tool=bestpractice.com
Previously scarred uterus
Screening by ultrasound with referral for colour flow Doppler ultrasound if PP is suspected.[2]Royal College of Obstetricians and Gynaecologists. Placenta praevia and placenta accreta: diagnosis and management. Green-top guideline no. 27a. Sep 2018 [internet publication].
https://www.rcog.org.uk/en/guidelines-research-services/guidelines/gtg27a
[3]Reddy UM, Abuhamad AZ, Levine D, et al. Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal-Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging Workshop. J Ultrasound Med. 2014 May;33(5):745-57.
http://www.ncbi.nlm.nih.gov/pubmed/24764329?tool=bestpractice.com
[4]American College of Obstetricians and Gynecologists / Society for Maternal-Fetal Medicine. ACOG SMFM obstetric care consensus #7: placenta accreta spectrum. Dec 2018 [internet publication].
https://www.acog.org/clinical/clinical-guidance/obstetric-care-consensus/articles/2018/12/placenta-accreta-spectrum
The radiologist should be informed about the risk of placenta accreta spectrum.[4]American College of Obstetricians and Gynecologists / Society for Maternal-Fetal Medicine. ACOG SMFM obstetric care consensus #7: placenta accreta spectrum. Dec 2018 [internet publication].
https://www.acog.org/clinical/clinical-guidance/obstetric-care-consensus/articles/2018/12/placenta-accreta-spectrum
Advice should be sought from the ultrasonographer or consultant obstetrician as to whether or not an MRI is indicated.[6]Getahun D, Oyelese Y, Salihu HM, et al. Previous cesarean delivery and risks of placenta previa and placental abruption. Obstet Gynecol. 2006 Apr;107(4):771-8.
http://www.ncbi.nlm.nih.gov/pubmed/16582111?tool=bestpractice.com
[9]Odibo AO, Cahill AG, Stamilio DM, et al. Predicting placental abruption and previa in women with a previous cesarean delivery. Am J Perinatol. 2007 May;24(5):299-305.
http://www.ncbi.nlm.nih.gov/pubmed/17514600?tool=bestpractice.com
[10]Qublan HS, Tahat Y. Multiple cesarean section. The impact on maternal and fetal outcome. Saudi Med J. 2006 Feb;27(2):210-4.
http://www.ncbi.nlm.nih.gov/pubmed/16501678?tool=bestpractice.com
[24]Wu S, Kocherginsky M, Hibbard JU. Abnormal placentation: twenty-year analysis. Am J Obstet Gynecol. 2005 May;192(5):1458-61.
http://www.ncbi.nlm.nih.gov/pubmed/15902137?tool=bestpractice.com
[31]Kallen B, Finnstrom O, Nygren KG, et al. In vitro fertilisation in Sweden: obstetric characteristics, maternal morbidity and mortality. BJOG. 2005 Nov;112(11):1529-35.
http://www.ncbi.nlm.nih.gov/pubmed/16225574?tool=bestpractice.com
[32]Shevell T, Malone FD, Vidaver J, et al. Assisted reproductive technology and pregnancy outcome. Obstet Gynecol. 2005 Nov;106(5 Pt 1):1039-45.
http://www.ncbi.nlm.nih.gov/pubmed/16260523?tool=bestpractice.com
Prior placenta praevia
PP has a moderate risk of recurrence (about 0.7%).[13]Ananth CV, Demissie K, Smulian JC, et al. Placenta previa in singleton and twin births in the United States, 1989 through 1998: a comparison of risk factor profiles and associated conditions. Am J Obstet Gynecol. 2003 Jan;188(1):275-81.
http://www.ncbi.nlm.nih.gov/pubmed/12548229?tool=bestpractice.com
Careful attention should be paid to the position of the placenta in subsequent pregnancies; ultrasound should be obtained mid second trimester.
In vitro fertilisation (IVF)
Pregnancies resulting from IVF have about a 2% risk of PP.[33]Reddy UM, Wapner RJ, Rebar RW, et al. Infertility, assisted reproductive technology, and adverse pregnancy outcomes: executive summary of a National Institute of Child Health and Human Development workshop. Obstet Gynecol. 2007 Apr;109(4):967-77.
http://www.ncbi.nlm.nih.gov/pubmed/17400861?tool=bestpractice.com
[34]Mukhopadhaya N, Arulkumaran S. Reproductive outcomes after in-vitro fertilization. Curr Opin Obstet Gynecol. 2007 Apr;19(2):113-9.
http://www.ncbi.nlm.nih.gov/pubmed/17353678?tool=bestpractice.com
[35]Romundstad LB, Romundstad PR, Sunde A, et al. Increased risk of placenta previa in pregnancies following IVF/ICSI; a comparison of ART and non-ART pregnancies in the same mother. Hum Reprod. 2006 Sep;21(9):2353-8.
https://academic.oup.com/humrep/article/21/9/2353/2938873
http://www.ncbi.nlm.nih.gov/pubmed/16728419?tool=bestpractice.com
Screening by ultrasound, at about 18 to 22 weeks' gestation, is indicated.[33]Reddy UM, Wapner RJ, Rebar RW, et al. Infertility, assisted reproductive technology, and adverse pregnancy outcomes: executive summary of a National Institute of Child Health and Human Development workshop. Obstet Gynecol. 2007 Apr;109(4):967-77.
http://www.ncbi.nlm.nih.gov/pubmed/17400861?tool=bestpractice.com
[34]Mukhopadhaya N, Arulkumaran S. Reproductive outcomes after in-vitro fertilization. Curr Opin Obstet Gynecol. 2007 Apr;19(2):113-9.
http://www.ncbi.nlm.nih.gov/pubmed/17353678?tool=bestpractice.com
[35]Romundstad LB, Romundstad PR, Sunde A, et al. Increased risk of placenta previa in pregnancies following IVF/ICSI; a comparison of ART and non-ART pregnancies in the same mother. Hum Reprod. 2006 Sep;21(9):2353-8.
https://academic.oup.com/humrep/article/21/9/2353/2938873
http://www.ncbi.nlm.nih.gov/pubmed/16728419?tool=bestpractice.com