一、妊?/span>早期?/span>?/span>
受孕后的3-12周左叻I是胚胎、胎儿各器官?/span>于高度分化、迅?/span>?/span>?/span>?/span>D，?/span>物媄晌此q?/span>E，可能?/span>致某些系l?/span>和器官畸形。可见妊?/span>12周内是致畸最敏感?/span>?/span>期。此期用药应特别慎重?/span>
?/span>?/span>?/span>与致畸的?/span>p?/span>?/span>
?/span>重的?/span>?/span>异常畸Ş主要?/span>生在器官形成期?/span>妊娠4个月以后Q胎?/span>l?/span>大多数器官己形成Q?/span>?/span>物致畸的敏感性降低，?/span>然不致造成?/span>重畸形，?/span>?/span>未分化完全的器?/span>(如生D系l?/span>)仍有可能?/span>?/span>; ?/span>l?/span>p?/span>l?/span>在整?/span>妊娠?/span>?/span>?/span>l分化?/span>?/span>Ԍ?/span>?/span>物的影晌一直存在。此外，有些?/span>?/span>?/span>胎儿的致怸良媄响，不表?/span>在新生儿期，而是在若q年后才?/span>C出来。如?/span>?/span>服用?/span>?/span>雌酚致生D道畸Ş?/span>?/span>道腺癌，至青春期才明?/span>表现出来?/span>
【对胎儿有害?/span>?/span>?/span>?/span>
甲}?/span>?/span>(?/span>?/span>畸Ş)?/span>?/span>酰?/span>(?/span>?/span>畸Ş)?/span>?/span>霉素(?/span>婴综合征的危?/span>性增?/span>) 、氯Z脌Ӏ甲苯磺丁脲(新生儿低血p、畸形率上升)、可的松(?/span>裂机率上?/span>)、卡那霉?昕力?/span>肾损?/span>) 、巴比妥c?/span>、地西n(?/span>期用?/span>新生?/span>对药物有?/span>?/span>?/span>)、四?/span>?/span>(?/span>?/span>、骨?/span>?/span>育障?/span>)?/span>?/span>?/span>(?/span>|膜?/span>?/span>)、三甲双?骨畸形、小?/span>畸Ş)、碳?/span>?/span>(心血畸?、乙??/span>期量大可?/span>?/span>?/span>骨、智力障胎儉K_?/span>l?/span>合征)、碘?/span>(先天性甲状腺?/span>大、甲状腺功能低下)、美沙酮、vz因(?/span>?/span>?/span>用新生儿对药物有?/span>?/span>?/span>)、甲N(x胎儿男性化)、抗雄性激?h胎儿女性化)?/span>?/span>雌酮?/span>炔诺?/span>(x胎儿男性化)、苯妥英?/span>(唇裂、腭?、丙氧嘧啶(先天性甲状腺?/span>?/span>)、沙立度?v肢畸?、三甲恶唑二?先天?/span>?/span>畸Ş)、双香豆?/span>c?/span>(ȝ形、眼?/span>実뀁智?/span>?/span>育障、心?/span>畸Ş、流?/span>、死胎、而)、苯?/span>利定(不育?、异l?/span>A?耳畸形?/span>?/span>畸Ş)、三环类抗抑郁症?/span>(血l?/span>?/span>?/span>?/span>)?/span>
?/span>?/span>?/span>?/span>?/span>?/span>明有致畸作用?/span>?/span>?/span>?/span>
乙醇: 早孕期日用量过2g/kg先天畸Ş发生率增?-3倍?/span>抗肿瘤药?/span>: 如白消安、苯丁酸氮芥、消卡芒芥、芥、环酰胺等;甲}蝶呤Q氟嘧Ӟ嘌呤，溶癌늭?/span>抗生?/span>:青霉胺、四环素、氯霉素{?/span>性甾体激?/span>:如乙烯雌酚、氯c{?/span>其他: 如一氧化뀁锂制剂( 酸? 、汞制剂(如甲基汞、硫化汞) ;视黄酸、丙戊酸钠、三甲双酮、苯妥英钠、沙立度?反应?及香豆素c?如华法林)?
q些药物应列为早孕期忌应用之列。但未列入的q无致畸性，而己列入的也未必是致畸性最强的。具有致畸性能药物应用后，是否出现畸Ş与孕妇暴露于该药旉长短、剂量大、胎龄等均有养I与致畸的机率也有相关。例丙戊酔R可致胎儿发生脊柱裂、小头畸形发生率增高Q但暴露于丙戊酸钠的孕妇仍有U?/span>95%的机会获得正常婴儿，对这些孕妇可借助声波检查、取水或血生化定Q及时决定可否l妊娠?/span>
?/span>药物对胎儿危害的分类标准?/span>
Ac?/span>:动物实验和床观察未见对胎儿有损宻I是最安全的一c，如青霉素钠?/span>
Bc?/span>:动物实验昄对胎仔有危害Q但临床研究未能证实Q或动物实验未发现有致畸作用Q但无床验证资料。多U床常用药属此c，例如U霉素、磺胺类、地高辛、氯苯那敏等?/span>
Cc?/span>:仅在动物实验证实对胎仔有致畸或杀胚胎的作用，但在人类~Z研究资料证实。如酸庆大霉素、氯霉素、盐酸异丙嗪{?/span>
Dc?/span>:临床有一定资料表明对胎儿有危宻I但治疗孕妇疾病的疗效肯定Q又无代替之药物Q其效益明显过其危xQ再考虑应用Q如抗惊厥药苯妥英钠Q以及链霉素{?/span>
Xc?/span>: 证实对胎儿有危害Qؓ妊娠期禁用的药物?/span>
二、中期和晚期妊娠用药问题
妊娠的中晚期Q药物对胎儿的致畸可能性减。但此时的牙、神l系l和x生D系l还在l分化发Ԍ药物的不良媄晌主要表现在上述各系l、各器官发育q缓和功能异常，此时期用药也应慎重，Ҏ(gu)用药适应证权衡利弊做出选择?/span>
三、妊娠期用药原则Q?/span>
单药有效的避免联合用药；有疗效肯定的老药避免用尚隄定对胎儿有无不良影响的新药；剂量有效的避免用大剂量。早孕期间避免?/span>CcRDc药物。若病情急需Q要应用肯定对胎儿有危害的药物，则应先终止妊娠，再用药?/span>
