男性精液品質長期趨勢分析及其危險因子之探討

根據國內推估，國內不孕症盛行率約為 15﹪，研究發現國外不孕症的盛行率約介於 6-24﹪之間，臨床上不孕夫妻的診斷中，男性因素約佔了 25-40﹪。因工商社會與科技進步形成的許多毒性物質、不良生活習慣與壓力等均可能危害男性精液品質，近年來男性精液品質有逐漸下降的趨勢，國外研究紛紛指出，WHO在 1999年所公佈的精液品質參考值已不符合實際狀況，所以本研究目的有二：第一個目的是比較正常生育力與低生育力男性的精液品質狀況（精蟲數、活動力與外觀等），找出國內正常生育與低生育力男性精液品質的判斷指標，提供未來制訂男性精液品質標準的建議。本研究收集正常生育力（ 53人）與低生育力男性（ 290人）的精液品質分析資料作比較，採用 Receiver operator characteristic（ ROC） curve訂定精液品質建議值；結果顯示低生育力男性具活動力精蟲與正常型態精蟲的比例顯著低於正常生育力男性，單一的精液品質指標中以正常型態精蟲比例最能判別出正常生育力的男性（敏感度： 94.34%，特異度： 71.72%）。本研究第二個目的是以病例對照研究法探討正常生育力與低生育力男性間的差異，本研究收集 55位正常生育力男性與 52位低生育力男性，以自塡性問卷收集夫妻雙方基本資料、生育史、職業史、健康狀況、生活習慣等資料，除計算等待懷孕時間（ Time to pregnancy； TTP）外，並收集血液與精液檢體，測定血中鉛、精液中鉛及血中四種生殖荷爾蒙－濾泡激素（ FSH）、黃體激素（ LH）、泌乳激素（ Prolactin）與睪固酮（ Testosterone）的含量；結果測得低生育力與正常生育力男性血中鉛平均值呈統計上顯著差異（ 59.20 ± 6.76 μg/l； 32.81 ± 1.31μg/l）；低生育力與正常生育力男性精液中鉛則無顯著差異（ 3.62 ± 1.47μg/l； 3.26 ± 0.46μg/l）；結果並顯示男性從事與鉛相關工作以及女性服用藥物會延長等待懷孕時間（ TTP），男性服用保健食品、女性有工作與睪固酮（ Testosterone）則會使其縮短；而調整干擾變項後血中鉛濃度大於 40 μg/l的男性，低生育力的機率（ OR=39.876, 95%C.I.= 3.656 - 434.903）明顯增加，精蟲正常率下降（ OR=0.326, 95%C.I.= 0.084 — 1.266）；而睪固酮（ Testosterone）則能使等待懷孕時間（ TTP）減少（ p=0.0364），使低生育力的機率降低（ OR=0.315, 95%C.I.= 0.161 — 0.617）並增加精蟲正常率（ OR=1.785, 95%C.I.=1.149 — 2.771）。

本研究建議以WHO制定的精蟲數量（≧ 20×106/ml）、精液量（≧ 2ml）與具活動力精蟲（≧ 50%）比例或活動力 III精蟲比例（≧ 25%），合併本研究正常型態精蟲比例建議值（ >50%）所組合而成的綜合指標作為判定可孕男性的參考值（敏感度： 66-68%，特異度： 80-82%），較為符合國內實際狀況。本研究也顯示男性低生育能力的危險因子有男性從事與鉛相關工作、男性血鉛值增加與配偶服用藥物有關，而其保護因子則有男性服用保健食品、睪固酮（ Testosterone）含量較高與配偶有工作等。

The prevalence of subfertility was 15% in our country. Many researches showed that 6-24% couples had experiences of subfertility, which is 25-40% attributed to male factor. In developed countries, environmental factors, lifestyles and stress have been suggested to play a role in human subfertility. Recent studies reported that semen qualities had decreased gradually. This study contains two aims. The first aim is to compare semen qualities in fertile and subfertile men and to provide information on value of semen qualities for predicting fertile male. Semen data from 53 fertile and 290 subfertile men were collected. We find the suggested values of semen qualities by receiver operator characteristic （ ROC） curve. The result shows that semen morphology (sensitivity: 94.34%, specificity: 71.72%) is the best criteria for male fertility. The secondary aim is to search for differences between fertile and subfertile men. A total of 55 fertile and 52 suberfertile men was recruited in this study. Their blood, semen samples and questionnaires were collected. The personal TTP（ Time to pergnancy） was calculated. The concentrations of blood lead, semen lead and four serum hormones（ FSH, LH, Prolactin and Testosterone） were also determinated. Results show that the differences of blood lead concentrations in fertile and subfertile men(3.62 ± 1.47μg/l vs. 3.26 ± 0.46μg/l) were statistically significant； but semen lead concentrations in fertile and subfertile men(3.62 ± 1.47μg/l vs. 3.26 ± 0.46μg/l) were not. In multiple regression, the result indicates positive impact of time to pregnancy and semen concentration with testosterone. A negative relation of semen concentration, time to pregnancy and subfertility with blood lead in logistic regression and multiple regression.

These results suggest that the sperm count 20×106/ml, semen volume 2ml, sperm morphology 50% ≧ ≧ ≧and sperm motility 50%≧ （ or sperm motility III 25%≧ ） are the suitable criterias for Taiwan males. The risk factors of male subfertility lead contaminated workers, blood lead concentration 40μg/l and wife t≧aking medicines,. Higher serum testosterone level, male taking healthy foods and wife having job were the protective factors.

Key words: semen quality, ROC curve, male subfertility, time to pergnancy