Article Figures & Data
Figures
- Figure 1.
Relation between gender of offspring and maternal risk of ovarian cancer in uniparous, biparous, and triparous women born before 1935 (3,219 cases and 15,810 controls for the three parities). Data are adjusted for age at diagnosis or enrollment, age at first childbirth, education level closest to age 40, and area of residence closest to age 40.
Tables
- Table 1.
Characteristics of the study subjects (n = 45,065)
Variables Cases (n = 7,407), n (%) Controls (n = 37,658), n (%) Age at diagnosis or enrollment (y) 17-29 148 (2.0) 868 (2.3) 30-39 741 (10.0) 3,974 (10.6) 40-49 2,003 (27.0) 10,177 (27.0) 50-59 2,594 (35.0) 13,054 (34.7) 60+ 1,921 (26.0) 9,585 (25.4) Parity 1 2,071 (28.0) 8,653 (23.0) 2 3,313 (44.7) 16,498 (43.8) 3 1,418 (19.1) 8,430 (22.4) 4 or more 605 (8.2) 4,077 (10.8) Age at 1st childbirth (y) 14-19 1,350 (18.2) 6,490 (17.2) 20-24 3,158 (42.6) 16,179 (43.0) 25-29 2,011 (27.2) 10,557 (28.0) 30-34 673 (9.1) 3,365 (9.0) 35+ 215 (2.9) 1,067 (2.8) Education level (y) <9 3,652 (49.3) 18,086 (48.0) ≥9 3,503 (47.3) 18,536 (49.2) Missing information 252 (3.4) 1,036 (2.8) Area of residence Urban 3,985 (53.8) 20,775 (55.2) Rural 3,422 (46.2) 16,883 (44.8) Gender of offspring All girls 2,007 (27.1) 8,836 (23.5) All boys 2,103 (28.4) 10,007 (26.6) Mixed boys and girls 3,297 (44.5) 18,815 (50.0) - Table 2.
Gender distribution of the offspring by birth order
Gender of offspring Cases Controls Boy (n)/girl (n) % Boy Boy (n)/girl (n) % Boy Birth order 1st child 3,773/3,634 50.9 19,467/18,191 51.7 2nd child 2,678/2,694 49.9 15,315/14,192 51.9 3rd child 1,057/997 51.5 6,766/6,237 52.0 4th child 312/302 50.8 2,181/2,083 51.2 5th child 91/77 54.2 709/653 52.1 6th and above 44/41 51.8 433/405 51.7 All children 7,955/7,745 50.7 44,871/41,761 51.8 - Table 3.
Number of boys and girls among ovarian cancer cases and control subjects and the associated OR with 95% CI
No. girls No. boys Adjusted OR*,† (95% CI) Birth year <1935, adjusted OR*,‡ (95% CI) 0 1 2 3+ 0 Cases — 998 797 212 1.00 (reference) 1.00 (reference) Control — 3,929 3,697 1,210 1 Cases 1,037 1,696 517 141 1.00 (0.94-1.06) 1.06 (0.97-1.15) Control 4,222 8,617 3,071 855 2 Cases 825 537 146 52 1.03 (0.95-1.11) 1.11 (0.99-1.25) Control 4,190 3,354 1,060 323 3+ Cases 241 139 48 21 1.13 (0.99-1.28) 1.33 (1.10-1.59) Control 1,595 944 376 215 Adjusted OR*,† (95% CI) 1.00 (reference) 0.92 (0.87-0.98) 0.87 (0.80-0.94) 0.82 (0.73-0.94) Birth year <1935, adjusted OR*,‡ (95% CI) 1.00 (reference) 0.90 (0.82-0.98) 0.84 (0.75-0.94) 0.85 (0.70-1.01) ↵* Data are adjusted for age at diagnosis or enrollment, age at first childbirth, parity, education level closest to age 40, and area of residence closest to age 40.
↵† P value from test for trend was <0.001 for number of boys and 0.16 for number of girls.
↵‡ P value from test for trend was 0.004 for number of boys and 0.006 for number of girls.
- Table 4.
Relation between gender of offspring and maternal risk of ovarian cancer in uniparous, biparous, triparous, and all women
Gender of offspring Cases/controls Crude OR (95% CI) Adjusted OR* (95% CI) Birth year <1935, adjusted OR* (95% CI) Among uniparous women (n = 10,724) Boy 1,058/4,478 0.97 (0.89-1.07) 0.97 (0.88-1.07) 0.94 (0.82-1.08) Girl 1,013/4,175 1.00 (reference) 1.00 (reference) 1.00 (reference) Among biparous women (n = 19,811) 1st child Boy 1,680/8,522 0.96 (0.89-1.04) 0.96 (0.89-1.04) 0.92 (0.82-1.02) Girl 1,633/7,976 1.00 (reference) 1.00 (reference) 1.00 (reference) 2nd child Boy 1,664/8,489 0.95 (0.88-1.03) 0.96 (0.89-1.03) 0.92 (0.82-1.03) Girl 1,649/8,009 1.00 (reference) 1.00 (reference) 1.00 (reference) 1st child/2nd child Boy/boy 826/4,200 0.91 (0.82-1.02) 0.91 (0.82-1.02) 0.84 (0.71-0.98) Boy/girl 854/4,322 0.92 (0.82-1.02) 0.91 (0.82-1.01) 0.87 (0.74-1.02) Girl/boy 838/4,289 0.91 (0.82-1.01) 0.90 (0.81-1.01) 0.87 (0.75-1.02) Girl/girl 795/3,687 1.00 (reference) 1.00 (reference) 1.00 (reference) Among triparous women (n = 9,848) 1st child Boy 722/4,403 0.95 (0.85-1.06) 0.95 (0.85-1.06) 0.93 (0.79-1.10) Girl 696/4,027 1.00 (reference) 1.00 (reference) 1.00 (reference) 2nd child Boy 703/4,423 0.89 (0.80-0.99) 0.89 (0.80-1.00) 0.83 (0.70-0.98) Girl 715/4,007 1.00 (reference) 1.00 (reference) 1.00 (reference) 3rd child Boy 727/4,431 0.95 (0.85-1.06) 0.94 (0.84-1.06) 0.98 (0.83-1.16) Girl 691/3,999 1.00 (reference) 1.00 (reference) 1.00 (reference) Three boys 196/1,276 0.81 (0.65-1.01) 0.81 (0.65-1.00) 0.72 (0.52-0.98) Two boys and one girl 526/3,249 0.86 (0.71-1.03) 0.85 (0.71-1.02) 0.76 (0.58-0.98) One boy and two girls 512/2,931 0.93 (0.77-1.11) 0.92 (0.76-1.10) 0.77 (0.59-1.01) Three girls 184/974 1.00 (reference) 1.00 (reference) 1.00 (reference) All women (n = 45,065) All boys 2,103/10,007 0.93 (0.87-0.99) 0.93 (0.87-0.99) 0.88 (0.80-0.97) Mixed boys and girls 3,297/18,815 0.77 (0.73-0.82) 0.89 (0.83-0.95) 0.89 (0.80-0.98) All girls 2,007/8,836 1.00 (reference) 1.00 (reference) 1.00 (reference) ↵* Data are adjusted for age at diagnosis or enrollment, age at first childbirth, education level closest to age 40, and area of residence closest to age 40. For biparous and triparous women, data are further adjusted for age at last birth with the previous covariates. For all women, data are further adjusted for parity.
- Table 5.
Associations between pregnancy-related hormones, offspring gender, and ovarian cancer risk
Pregnancy-related hormones and proteins (1) Possible association between hormone and ovarian cancer risk (2) Possible association between bearing male offspring and hormone* (3) Predicted association between bearing male offspring and maternal ovarian cancer risk† Agreement between the present findings and the predicted association‡ Estrogen ↑/− ↓ −/↓ Partial agreement Androgens ↑ ↑/− ↑/− Disagreement Progesterone ↓ ↑/− −/↓ Partial agreement hCG ↓ ↓ ↑ Disagreement IGF-I ↑ −/↓ −/↓ Partial agreement α-Fetoprotein 0 ↑ 0 Undetermined NOTE: ↑, positive association; ↓, inverse association; −, null association; 0, no information.
↵* Compared with bearing female offspring.
↵† Predicted associations, based on the possible associations in (1) and (2), between bearing male offspring and ovarian cancer risk.
↵‡ Agreement or disagreement between the predicted and our observed associations between bearing male offspring and maternal ovarian cancer risk.
Volume 16, Issue 11
