Int J Cancer. 2006 Sep 1;119(5):1108-24. doi: 10.1002/ijc.21953.
The International Collaboration of Epidemiological Studies of Cervical Cancer has combined individual data on 11,161 women with invasive carcinoma, 5,402 women with cervical intraepithelial neoplasia (CIN)3/carcinoma in situ and 33,542 women without cervical carcinoma from 25 epidemiological studies. Relative risks (RRs) and 95% confidence intervals (CIs) of cervical carcinoma in relation to number of full-term pregnancies, and age at first full-term pregnancy, were calculated conditioning by study, age, lifetime number of sexual partners and age at first sexual intercourse. Number of full-term pregnancies was associated with a risk of invasive cervical carcinoma. After controlling for age at first full-term pregnancy, the RR for invasive cervical carcinoma among parous women was 1.76 (95% CI: 1.53-2.02) for > or => or =7 full-term pregnancies compared with 1-2. For CIN3/carcinoma in situ, no significant trend was found with increasing number of births after controlling for age at first full-term pregnancy among parous women. Early age at first full-term pregnancy was also associated with risk of both invasive cervical carcinoma and CIN3/carcinoma in situ. After controlling for number of full-term pregnancies, the RR for first full-term pregnancy at age <17 years compared with > or => or =25 years was 1.77 (95% CI: 1.42-2.23) for invasive cervical carcinoma, and 1.78 (95% CI: 1.26-2.51) for CIN3/carcinoma in situ. Results were similar in analyses restricted to high-risk human papilloma virus (HPV)-positive cases and controls. No relationship was found between cervical HPV positivity and number of full-term pregnancies, or age at first full-term pregnancy among controls. Differences in reproductive habits may have contributed to differences in cervical cancer incidence between developed and developing countries.
宫颈癌流行病学研究国际协作组汇总了来自25项流行病学研究的11161例浸润性癌女性、5402例宫颈上皮内瘤变（CIN）3/原位癌女性以及33542例无宫颈癌女性的个体数据。根据研究、年龄、性伴侣终生数量和首次性交年龄进行校正后，计算了与足月妊娠次数及首次足月妊娠年龄相关的宫颈癌相对风险（RR）和95%置信区间（CI）。足月妊娠次数与浸润性宫颈癌风险相关。在控制首次足月妊娠年龄后，经产妇中足月妊娠≥7次者浸润性宫颈癌的RR为1.76（95%CI：1.53 - 2.02），而1 - 2次者为对照。对于CIN3/原位癌，在控制经产妇首次足月妊娠年龄后，未发现随着生育次数增加有显著趋势。首次足月妊娠年龄早也与浸润性宫颈癌和CIN3/原位癌风险相关。在控制足月妊娠次数后，首次足月妊娠年龄＜17岁者与≥25岁者相比，浸润性宫颈癌的RR为1.77（95%CI：1.42 - 2.23），CIN3/原位癌的RR为1.78（95%CI：1.26 - 2.51）。在仅限于高危人乳头瘤病毒（HPV）阳性病例和对照的分析中结果相似。在对照中未发现宫颈HPV阳性与足月妊娠次数或首次足月妊娠年龄之间存在关联。生殖习惯的差异可能导致了发达国家和发展中国家宫颈癌发病率的差异。
