title: To ignore or not to ignore placental calcifications on prenatal ultrasound: a systematic review and meta-analysis.
abstract: OBJECTIVE
  The human placenta is known to calcify with advancing gestational age, and, in fact, the presence of significant calcifications is one of the components of grade III placenta, typical of late gestation. As such, the presence of significant placental calcifications often prompts obstetric providers to expedite delivery. This practice has been attributed, in part, to the presumed association between grade III placenta and adverse pregnancy outcomes. Such approach, however, can be the source of major anxiety and may lead to unnecessary induction of labor, with its associated predisposition to cesarean delivery as well as a myriad of maternal and neonatal morbidities. The objective of this study was to examine the association between grade III placental calcifications and pregnancy outcomes.
  
  
  METHODS
  A systematic review of the literature was performed for studies evaluating the association between grade III placenta and a number of pregnancy outcomes, including labor induction, fetal distress (abnormal fetal heart tracing), low Apgar score (less than 7 at 5 min), need for neonatal resuscitation, admission to the Neonatal Intensive Care Unit, perinatal death, meconium liquor, and low birth weight.
  
  
  RESULTS
  There was a five-fold increase in risk of labor induction with the presence of grade III placenta (OR 5.41; 95% CI 2.98-9.82). There was no association between grade III placenta and the incidence of abnormal fetal heart tracing (OR 1.62; 95% CI 0.94-2.78), low Apgar score of less than 7 at 5 min (OR 1.68; 95% CI 0.84-3.36), need for neonatal resuscitation (OR 1.08; 95% CI 0.67-1.75), and admission to the Neonatal Intensive Care Unit (OR 0.90; 95% CI 0.21-3.74). In turn, the incidence of meconium liquor was higher in the setting of grade III placentae (OR 1.68; 95% CI 1.17-2.39). Similarly, a positive association between grade III placental calcifications and low birth weight (OR 1.63; 95% CI 1.19-2.22) and perinatal death (OR 7.41; 95% CI 4.94-11.09) was identified.
  
  
  CONCLUSIONS
  The study alerts us to a significant association between grade 3 placental calcifications and labor induction, although it demonstrates that these sonographic findings do not appear to predispose to fetal distress, low Apgar score, need for neonatal resuscitation, or admission to the NICU.
authors.affiliation: a Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology , American University of Beirut Medical Center, Faculty of Medicine and Medical Center , Beirut , Lebanon.|b Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology , Columbia University Medical Center , New York , NY , USA.
authors.forename: Fadi G
authors.initials: FG
authors.lastname: Mirza
authors.affiliation: a Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology , American University of Beirut Medical Center, Faculty of Medicine and Medical Center , Beirut , Lebanon.
authors.forename: Labib M
authors.initials: LM
authors.lastname: Ghulmiyyah
authors.affiliation: c Biostatistics Unit, Clinical Research Institute , American University of Beirut Medical Center , Beirut , Lebanon.
authors.forename: Hani
authors.initials: H
authors.lastname: Tamim
authors.affiliation: c Biostatistics Unit, Clinical Research Institute , American University of Beirut Medical Center , Beirut , Lebanon.
authors.forename: Maha
authors.initials: M
authors.lastname: Makki
authors.affiliation: a Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology , American University of Beirut Medical Center, Faculty of Medicine and Medical Center , Beirut , Lebanon.
authors.forename: Dima
authors.initials: D
authors.lastname: Jeha
authors.affiliation: a Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology , American University of Beirut Medical Center, Faculty of Medicine and Medical Center , Beirut , Lebanon.
authors.forename: Anwar
authors.initials: A
authors.lastname: Nassar
mesh_terms: D001034:Apgar Score; D002114:Calcinosis / Q000145:classification / Q000000981:diagnostic imaging*; D005260:Female; D005316:Fetal Distress / Q000209:etiology; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007751:Labor, Induced / Q000009:adverse effects / Q000706:statistics & numerical data*; D008470:Meconium; D066087:Perinatal Death; D010920:Placenta / Q000000981:diagnostic imaging* / Q000378:metabolism; D011247:Pregnancy; D012151:Resuscitation; D012307:Risk Factors; D016216:Ultrasonography, Prenatal
keywords: Calcifications; fetal growth restriction; outcome; placenta; pregnancy