Levy H L
Children's Hospital, Boston, Mass.
Enzyme. 1987;38(1-4):312-20.
Maternal phenylketonuria (PKU) refers to fetal damage from PKU in the pregnant woman. The progeny from such pregnancies are almost always microcephalic and mentally subnormal and have an increased frequency of congenital heart disease and low birth weight. Treatment with a phenylalanine-restricted diet, if begun before conception, seems to protect the fetus. The degree of protection is much less if dietary treatment is delayed until the pregnancy is in progress. The origin of fetal damage in maternal PKU is not known. Due to placental concentration of amino acids, the fetus is exposed to a higher concentration of phenylalanine than that in the mother, but it is not certain that phenylalanine is the toxic agent. Animal models made hyperphenylalaninemic by the administration of phenylalanine, often accompanied by a phenylalanine hydroxylase inhibitor, do not reproduce the full maternal PKU syndrome; but fetuses and newborns from these models have had reduced growth of the body and brain, and offspring later may show evidence of impaired learning ability.
母体苯丙酮尿症（PKU）是指孕妇患苯丙酮尿症对胎儿造成的损害。此类妊娠的后代几乎总是小头畸形且智力发育不正常，先天性心脏病的发病率增加，出生体重低。如果在受孕前开始采用限制苯丙氨酸的饮食进行治疗，似乎可以保护胎儿。如果饮食治疗推迟到孕期进行，保护程度会低得多。母体苯丙酮尿症中胎儿损害的起源尚不清楚。由于胎盘对氨基酸的浓缩作用，胎儿接触的苯丙氨酸浓度高于母亲，但尚不能确定苯丙氨酸就是有毒物质。通过给予苯丙氨酸（通常伴有苯丙氨酸羟化酶抑制剂）使动物模型产生高苯丙氨酸血症，并不会重现完整的母体苯丙酮尿症综合征；但这些模型中的胎儿和新生儿身体和大脑生长减缓，其后代后期可能表现出学习能力受损的迹象。
