Seppälä M, Rutanen E M, Jalanko H, Lehtovirta P, Stenman U H, Engvall E
J Clin Endocrinol Metab. 1978 Dec;47(6):1216-9. doi: 10.1210/jcem-47-6-1216.
In a cross-sectional study, the serum levels of pregnancy-specific beta 1-glycoprotein (PSBG), hCG, human LH, and progesterone were measured by RIAs during 94 mid or late luteal phases of 69 women using oral contraceptives. Subsequent spontaneous menstruation took place in every cycle. None of the women using oral contraceptives had any PSBG or hCG-like immunoreactivity in serum. In women with intrauterine devices, PSBG was found in six cycles (6.4%) and hCG-like immunoreactivity was demonstrated in one cycle only, where PSBG also was present. In two out of six PSBG-positive cycles, menstruation was delayed by 5 and 16 days. Although rare, the transient occurrence of trophoblastic antigens in women using intrauterine contraception is taken as evidence for an occult pregnancy in these apparently infertile cycles.
在一项横断面研究中，在69名使用口服避孕药的妇女的94个黄体中期或后期，通过放射免疫分析法测定血清中妊娠特异性β1-糖蛋白（PSBG）、人绒毛膜促性腺激素（hCG）、人促黄体生成素（LH）和孕酮的水平。随后每个周期都出现了自然月经。使用口服避孕药的妇女血清中均未检测到任何PSBG或hCG样免疫反应性。在使用宫内节育器的妇女中，6个周期（6.4%）检测到PSBG，仅在1个周期检测到hCG样免疫反应性，该周期也存在PSBG。在6个PSBG阳性周期中的2个周期，月经分别推迟了5天和16天。尽管罕见，但使用宫内节育器的妇女中滋养层抗原的短暂出现被视为这些明显不孕周期中存在隐匿性妊娠的证据。
