Bernstein L, Depue R H, Ross R K, Judd H L, Pike M C, Henderson B E
J Natl Cancer Inst. 1986 Jun;76(6):1035-9.
Serum samples drawn from 34 women in the early part of both their first and their second pregnancies were assayed for estradiol (E2), percentage of free E2, and sex hormone-binding globulin-binding capacity (SHBG-bc). Subjects were participants in the Collaborative Perinatal Study conducted by the National Institute of Neurological and Communicative Disorders and Stroke (Bethesda, MD) to evaluate factors related to adverse pregnancy outcome. All pregnancies were full term, and no offspring had a congenital malformation. After adjustment for week of pregnancy, the percentage of free E2 was 9% higher (two-sided P = .007) and the amount of free E2 was 17% higher (two-sided P = .03) in first-pregnancy sera. Total E2 was also 7% higher in first-pregnancy sera after adjustment for week of pregnancy; SHBG-bc was 7% lower after adjustment for week of pregnancy and 9% lower after simultaneous adjustment for week of pregnancy and weight at the start of pregnancy; but these differences were not statistically significant. These findings confirm our previously published hypothesis that the early part of a woman's first pregnancy differs endocrinologically from her second and may provide further insight into pregnancy-related risk factors for testis cancer and cryptorchidism and into the protection afforded by first full-term pregnancy against breast cancer.
采集了34名女性在首次和第二次怀孕早期的血清样本，检测其中雌二醇（E2）、游离E2百分比以及性激素结合球蛋白结合能力（SHBG-bc）。这些受试者参与了由国立神经疾病和中风研究所（马里兰州贝塞斯达）开展的围产期协作研究，以评估与不良妊娠结局相关的因素。所有妊娠均为足月产，且无后代患有先天性畸形。在对孕周进行校正后，首次怀孕血清中的游离E2百分比高出9%（双侧P = 0.007），游离E2量高出17%（双侧P = 0.03）。在对孕周进行校正后，首次怀孕血清中的总E2也高出7%；在对孕周进行校正后，SHBG-bc降低了7%，在同时对孕周和怀孕开始时的体重进行校正后，SHBG-bc降低了9%；但这些差异无统计学意义。这些发现证实了我们之前发表的假设，即女性首次怀孕早期在内分泌方面与第二次怀孕不同，这可能会进一步深入了解睾丸癌和隐睾症的妊娠相关危险因素，以及首次足月妊娠对乳腺癌的保护作用。
