Table 2 Adjusted relative risk for live-birth according to cleavage-stage embryo quality

Q1 (1 point)

1.00 (reference)

1.00 (reference)

1.00 (reference)

Q2 (2 points)

1.99 (1.62–2.44)

1.94 (1.57–2.39)

1.93 (1.56–2.38)

Q3 (3 points)

2.43 (1.98–2.98)

2.35 (1.91–2.90)

2.34 (1.89–2.88)

Q4 (4 points)

2.88 (2.35–3.53)

2.74 (2.21–3.40)

2.72 (2.19–3.38)

Q5 (5 points)

3.07 (2.50–3.76)

2.92 (2.35–3.62)

2.90 (2.33–3.60)

Q6 (6 points)

3.27 (2.64–4.06)

3.12 (2.48–3.91)

3.10 (2.47–3.89)

P_{for trend}

<0.001

<0.001

<0.001