Table 1 Main characteristics of the included studies in the systematic review and meta analyses
Row | First author, publication year | Study design | Study period | Study subjects | Placenta Previa diagnosis | Congenital abnormalities type | Total Sample size (subject with PP) | Crude OR (95% CI) | Adjusted OR (95% CI); adjustment factors | Quality of study |
|---|---|---|---|---|---|---|---|---|---|---|
1 | Anwar, 2020 | Hospital-based Cohort | 2012-15 | Group A: PP with & Without congenital malformation. Group B: Absence of PP with & Without congenital malformation | Second or third trimester ultrasonography | All structural anomalies, chromosomal defects, and congenital hypothyroidisms | 90, 223 (1076) | Not reported | Not reported | High |
2 | Kancherla, 2015 | Population-based Cohort | 2000-10 | All singletons born at or after 22 ± 0 weeks of gestation | Second or third trimester ultrasonography | Congenital abnormalities (including Major structural anomalies and chromosomal defects) | 621,163 (1644) | 1.65, (1.35,2.02) | 1.55; (1.27,1.90) Maternal age, parity, fetal Sex, smoking, Socioeconomic status, chorionic villus biopsy, IVF, pre-existing Diabetes, depression, preeclampsia, and prior caesarean Section | High |
3 | Rosenberg, 2011 | Hospital-based Cohort | 1988–2009 | Singletons | Second or third trimester ultrasonography | Congenital abnormalities (types not specified) | 185,476 (771) | 2.4 (1.9,3.0) | Not reported | High |
4 | Salihu, 2003 | Population-based Cohort | 1997 | Singleton, Livebirths | Birth certificate | Congenital abnormalities (types not specified) | 3,772,369 (9656) | 1.11 (0.99,1.26) | Not reported | High |
5 | Sheiner, 2001 | Hospital-based Cohort | 1990–98 | Singletons over 22 weeks of Gestation | Ultrasound and During delivery | Congenital abnormalities Including structural and Chromosomal anomalies | 78,524 (298) | 2.6 (1.5,4.2) | 16.1 (13.4,19.3); Unknown | High |
6 | Crane, 1999 | Population-based Cohort | 1988-95 | Singletons over 20 weeks of Gestation | Ultrasound /at Deliveries by Double-set or Caesarean Section | Cardiovascular, gastrointestinal, Respiratory, otolaryngology, Genitourinary, dermatologic, musculoskeletal, neurologic, and Chromosomal anomalies | 92,983 (305) | 2.52 (1.52, 4.17) | 2.48 (1.50,4.11); Maternal age | High |
7 | Neri, 1989 | Hospital-based Case-Control | 1980-86 | Unknown | Ultrasound | Congenital heart defects | 164 (82) | Not reported | Not reported | Low |
8 | Brenner, 1978 | Hospital-based Cohort | 1962-69 | Singletons At each gestational age | 1131-albuminalbumin radioisotope technique | Congenital abnormalities Including structural &Chromosomal anomalies | 31,070 (185) | Not reported | Not reported | High |