TY - JOUR
T1 - Risk of preterm birth for placenta previa or low-lying placenta and possible preventive interventions
T2 - A systematic review and meta-analysis
AU - Jansen, Charlotte H. J. R.
AU - van Dijk, Charlotte E.
AU - Kleinrouweler, C. Emily
AU - Holzscherer, Jacob J.
AU - Smits, Anouk C.
AU - Limpens, Jacqueline C. E. J. M.
AU - Kazemier, Brenda M.
AU - van Leeuwen, Elisabeth
AU - Pajkrt, Eva
N1 - Publisher Copyright: Copyright © 2022 Jansen, van Dijk, Kleinrouweler, Holzscherer, Smits, Limpens, Kazemier, van Leeuwen and Pajkrt.
PY - 2022/9/2
Y1 - 2022/9/2
N2 - Objective: To investigate the risk of preterm birth in women with a placenta previa or a low-lying placenta for different cut-offs of gestational age and to evaluate preventive interventions. Search and methods: MEDLINE, EMBASE, CENTRAL, Web of Science, WHO-ICTRP and clinicaltrials.gov were searched until December 2021. Randomized controlled trials, cohort studies and case-control studies assessing preterm birth in women with placenta previa or low-lying placenta with a placental edge within 2 cm of the internal os in the second or third trimester were eligible for inclusion. Pooled proportions and odds ratios for the risk of preterm birth before 37, 34, 32 and 28 weeks of gestation were calculated. Additionally, the results of the evaluation of preventive interventions for preterm birth in these women are described. Results: In total, 34 studies were included, 24 reporting on preterm birth and 9 on preventive interventions. The pooled proportions were 46% (95% CI [39 – 53%]), 17% (95% CI [11 – 25%]), 10% (95% CI [7 – 13%]) and 2% (95% CI [1 – 3%]), regarding preterm birth <37, <34, <32 and <28 weeks in women with placenta previa. For low-lying placentas the risk of preterm birth was 30% (95% CI [19 – 43%]) and 1% (95% CI [0 – 6%]) before 37 and 34 weeks, respectively. Women with a placenta previa were more likely to have a preterm birth compared to women with a low-lying placenta or women without a placenta previa for all gestational ages. The studies about preventive interventions all showed potential prolongation of pregnancy with the use of intramuscular progesterone, intramuscular progesterone + cerclage or pessary. Conclusions: Both women with a placenta previa and a low-lying placenta have an increased risk of preterm birth. This increased risk is consistent across all severities of preterm birth between 28-37 weeks of gestation. Women with placenta previa have a higher risk of preterm birth than women with a low-lying placenta have. Cervical cerclage, pessary and intramuscular progesterone all might have benefit for both women with placenta previa and low-lying placenta, but data in this population are lacking and inconsistent, so that solid conclusions about their effectiveness cannot be drawn. Systematic review registration: PROSPERO https://www.crd.york.ac.uk/prospero/, identifier CRD42019123675.
AB - Objective: To investigate the risk of preterm birth in women with a placenta previa or a low-lying placenta for different cut-offs of gestational age and to evaluate preventive interventions. Search and methods: MEDLINE, EMBASE, CENTRAL, Web of Science, WHO-ICTRP and clinicaltrials.gov were searched until December 2021. Randomized controlled trials, cohort studies and case-control studies assessing preterm birth in women with placenta previa or low-lying placenta with a placental edge within 2 cm of the internal os in the second or third trimester were eligible for inclusion. Pooled proportions and odds ratios for the risk of preterm birth before 37, 34, 32 and 28 weeks of gestation were calculated. Additionally, the results of the evaluation of preventive interventions for preterm birth in these women are described. Results: In total, 34 studies were included, 24 reporting on preterm birth and 9 on preventive interventions. The pooled proportions were 46% (95% CI [39 – 53%]), 17% (95% CI [11 – 25%]), 10% (95% CI [7 – 13%]) and 2% (95% CI [1 – 3%]), regarding preterm birth <37, <34, <32 and <28 weeks in women with placenta previa. For low-lying placentas the risk of preterm birth was 30% (95% CI [19 – 43%]) and 1% (95% CI [0 – 6%]) before 37 and 34 weeks, respectively. Women with a placenta previa were more likely to have a preterm birth compared to women with a low-lying placenta or women without a placenta previa for all gestational ages. The studies about preventive interventions all showed potential prolongation of pregnancy with the use of intramuscular progesterone, intramuscular progesterone + cerclage or pessary. Conclusions: Both women with a placenta previa and a low-lying placenta have an increased risk of preterm birth. This increased risk is consistent across all severities of preterm birth between 28-37 weeks of gestation. Women with placenta previa have a higher risk of preterm birth than women with a low-lying placenta have. Cervical cerclage, pessary and intramuscular progesterone all might have benefit for both women with placenta previa and low-lying placenta, but data in this population are lacking and inconsistent, so that solid conclusions about their effectiveness cannot be drawn. Systematic review registration: PROSPERO https://www.crd.york.ac.uk/prospero/, identifier CRD42019123675.
KW - cerclage
KW - low-lying placenta
KW - pessary
KW - placenta previa
KW - preterm birth
KW - preventive interventions
KW - progesterone
UR - http://www.scopus.com/inward/record.url?scp=85138157523&partnerID=8YFLogxK
U2 - https://doi.org/10.3389/fendo.2022.921220
DO - https://doi.org/10.3389/fendo.2022.921220
M3 - Review article
C2 - 36120450
SN - 1664-2392
VL - 13
JO - Frontiers in Endocrinology
JF - Frontiers in Endocrinology
M1 - 921220
ER -