Table 2.
Duration of gestation and infant birth weight for the live-born children of female childhood cancer survivors and female siblings*
| No. of live-born children of |
||||
|---|---|---|---|---|
| Outcome | Survivors (N = 2201), N (%) |
Siblings (N = 1175), N (%) |
OR (95% CI) | P† |
| Duration of gestation |
||||
| Preterm‡ | 441 (21.1) | 145 (12.6) | 1.9 (1.4 to 2.4) | <.001 |
| Full term‡ | 1653 (78.9) | 1007 (87.4) | Referent | |
| Unknown | 107 | 23 | ||
| Birth weight, g§ | ||||
| <1500 | 37 (1.8) | 9 (0.8) | ||
| 1500–1999 | 37 (1.8) | 9 (0.8) | ||
| 2000–2499 | 115 (5.5) | 30 (2.6) | ||
| 2500–2999 | 354 (16.8) | 170 (14.9) | ||
| 3000–3499 | 751 (35.6) | 371 (32.5) | ||
| 3500–3999 | 581 (27.6) | 390 (34.2) | ||
| ≥4000 | 233 (11.1) | 163 (14.3) | ||
| Unknown | 93 | 33 | ||
| LBW∥ | 189 (9.0) | 48 (4.2) | 1.3 (0.9 to 1.9)¶ | .23 |
| Non-LBW∥ | 1919 (91.0) | 1094 (95.8) | Referent | |
| SGA# | ||||
| Yes | 191 (9.5) | 101 (9.2) | 1.0 (0.8 to 1.4) | .84 |
| No | 1815 (90.5) | 1002 (90.8) | Referent | |
| Unknown | 195 | 72 | ||
Odds ratios were adjusted for maternal age, birth order, sex of child, maternal drinking of alcohol during pregnancy, maternal smoking of cigarettes during pregnancy, and the use of assisted reproductive technology. Odds ratios for low birth weight were further adjusted for gestational week at birth. OR = odds ratio; CI = confidence interval.
P values (two-sided) were calculated based on a z score using empirical standard error estimates derived from a logistic regression model using generalized estimating equations.
Preterm birth = less than 37 weeks gestation; full-term birth = 37 weeks gestation or longer.
Birth weight of survivors versus siblings, P <.001 (chi-square, two-sided test).
LBW = low birth weight = birth weight less than 2.5 kg; Non-LBW = birth weight 2.5 kg and greater.
The odds ratio adjusting for all listed confounders except gestational week at birth was 2.1 (95% CI = 1.5 to 2.9).
SGA = small-for-gestational-age, defined as birth weight in the bottom 10th percentile for infants of the same sex born on the same gestational week, using the standard of Alexander et al. (19).