Skip to main content

Table 1 Weight at the three assessment times for fresh ART, frozen ART (FET) and naturally conceived (NC) singleton babies

From: The growth of assisted reproductive treatment-conceived children from birth to 5 years: a national cohort study

  Adjusted BW (GROW)
N = 26,010
Weight at 6/8 weeks
N = 19,028
Weight at school entry
N = 11,573
Effect size (95% CI) (g) P Effect size (95% CI) (g) P Effect size (95% CI) (g) P
Type of conception
 Naturally Conceived Reference < 0.001 Reference < 0.001 Reference 0.340
 ART - Fresh Cycle -93.7 (-110.6, -76.6) -171 (-200, -143) -58 (-231, 115)
 ART - Frozen Cycle 57.5 (30.7, 86.5) 1 (-47, 49) 200 (-135, 560)
Scottish Deprivation Index Quintile
 1 (most deprived) -44.6 (-64.2, -25.7) < 0.001 -48 (-80, -17) 0.052 38 (-168, 240) 0.131
 2 -25.1 (-44.1, -6.4) -25 (-57, 4) 229 (42, 430)
 3 -6.8 (-24.3, 10.3) -32 (-61, 0) 104 (-74, 294)
 4 3.8 (-13.8, 22.0) -15 (-48, 13) 29 (-150, 201)
 5 (least deprived) Reference Reference Reference
Smoked during pregnancy -211.1 (-227.6, -195.2) < 0.001 -190 (-216, -163) < 0.001 -40 (-194, 136) 0.638
Maternal age (linear) 41.3 (30.1, 52.2) < 0.001 -7 (-25, 12) < 0.001 118 (3, 240) 0.011
Maternal age (quadratic) -20.8 (-35.6, -8.1) -52 (-75, -29) -121 (-266, 17)
Type of feeding
 Breast only    Reference < 0.001 Reference 0.125
 Bottle only    77 (54, 98) 99 (-31, 229)
 Breast and bottle    -9 (-52, 30) 229 (-25, 501
  1. Results from multiple linear regression models for weight at the three time points, adjusting for type of conception, Scottish Index of Multiple Deprivation, maternal age and smoking status during pregnancy, feed type at 10 days and the ART-NC matching variables: gender, year and month of delivery and delivery hospital. Full model details are available in Additional file 1: Table S4
  2. Quoted effect sizes represent the difference from the indicated reference category. The effect size for maternal smoking represents the difference between mothers who smoked and those who did not smoke during pregnancy
  3. P values are calculated from an omnibus chi-squared test that parameter estimates are simultaneously zero
  4. Note that for ease of interpretation, the effect sizes for the linear and quadratic components of maternal age represent the change in outcome for a 10-year change in maternal age