Table 1:
Study | Type of Study | Fetal genes | Maternal genes | Limitations |
---|---|---|---|---|
Boyd et al.33 | Population epidemiology | − | + | No distinction between sPTB and medically-induced |
Clausson et al.42 | Twin mothers study | NA | + | No distinction between sPTB and medically-induced |
Kistka et al.41 | Twin mothers study | − | ++ | No distinction between sPTB and medically-induced |
Lunde et al.36 | Population-based (parent-infant pair) | + | + | Excluded births <35 weeks, used gestational age as quantitative trait |
Plunkett et al.37 | Segregation analysis (mother-infant pair) | + | ++ | Potential confounding between maternal & fetal estimates |
Svensson et al.39 | Population epidemiology (Children of siblings) | − | ++ | Categorically defined preterm birth (<37 weeks) |
Treloar et al44 | Twin mothers study | NA | ++ | No distinction between sPTB and medically-induced |
Wilcox et al.46 | Population epidemiology (mother-infant pair) | − | ++ | Categorically defined preterm birth (<37 weeks) |
Wu et al.38 | Population epidemiology (mother-infant pair) | − | ++ | Not able to control for environmental risk factors |
York et al.40 | Twin mothers study | + | + | Excluded births <30 weeks |
No evidence of genetic contribution
Moderate genetic contribution
Strong genetic contribution
NA, Not available