Leveno K J, Santos-Ramos R, Duenhoelter J H, Reisch J S, Whalley P J
Am J Obstet Gynecol. 1980 Nov 15;138(6):615-9. doi: 10.1016/0002-9378(80)90076-9.
Sonar measured biparietal diameter (BPD) differences of twin paires were examined in 123 twin pregnancies at or beyond 28 weeks' gestation. Among 117 liveborn sets, the risk of a twin infant being small for gestational age was threefold greater when paired BPD differences were 5 mm or more compared to 4 mm or less. The incidence of fetal death increased from 2.7% for twin pairs with 0 to 6 mm BPD differences to 20% when the difference was 7 mm or more. Sonar cephalometry may be helpful in the antepartum evaluation of twin pregnancies, although detection of BPD discordancy does not preclude normal twin outcome.
在123例妊娠28周及以上的双胎妊娠中，通过超声测量双胎双顶径（BPD）差异。在117例活产双胎中，当双胎双顶径差异为5毫米或更大时，与4毫米或更小相比，双胎中一个胎儿小于孕周的风险增加了两倍。胎儿死亡发生率从双胎双顶径差异为0至6毫米时的2.7%增加到差异为7毫米或更大时的20%。超声头测量法可能有助于双胎妊娠的产前评估，尽管检测到双顶径不一致并不排除双胎有正常结局。
