孕早期颈项透明层增厚与胎儿结构畸形的关系

Relationship between nuchal translucency thickness and fetal structural anomalies

目的探讨颈项透明层(nuchal translucency,NT)厚度与孕早期胎儿结构畸形的关系。方法孕11~13+6周单胎妊娠孕妇6399例,均行超声检查筛查胎儿结构畸形、测量NT厚度,并依据胎儿NT厚度分为NT正常组(NT厚度<3.5 mm)5925例和NT增厚组(NT厚度≥3.5 mm)474例。有结构畸形选择继续妊娠者、未发现结构畸形者,于孕中晚期重复行超声检查,必要时进行产前诊断,发现致死性结构畸形建议终止妊娠,非致死性结构畸形根据孕妇意愿选择终止妊娠或继续妊娠。继续妊娠者随访至新生儿出生后6个月。记录2组终止妊娠、胚胎停止发育、引产、早产、足月产例数;比较2组胎儿结构畸形发生率及畸形部位差异。再将NT增厚组分为3.5~<4.5 mm组197例、4.5~<5.5 mm组94例、5.5~<6.5 mm组55例、≥6.5 mm组128例,比较不同亚组胎儿结构畸形发生率。结果NT正常组胚胎停止发育11例,引产106例,早产11例,足月产5797例;NT增厚组停止发育6例,引产192例,早产3例,足月产273例。NT增厚组胎儿结构畸形发生率(26.6%)较NT正常组(2.4%)高(P<0.05);≥6.5 mm组、5.5~<6.5 mm组结构畸形发生率(43.0%、34.5%)均高于3.5~<4.5 mm组(15.2%),且≥6.5 mm组高于4.5~<5.5 mm组(23.4%)(P<0.05),≥6.5 mm组与5.5~<6.5 mm组、4.5~<5.5 mm组与3.5~<4.5 mm组胎儿结构畸形比较差异无统计学意义(P>0.05)。NT增厚组心血管系统畸形发生率(57.9%)高于NT正常组(18.7%),中枢神经系统、腹腔脏器畸形发生率(12.7%、9.5%)低于NT正常组(32.6%、22.9%)。结论孕早期NT增厚的胎儿较易伴有结构畸形,且胎儿结构畸形发生率随NT厚度增加而增高,其中以心血管系统结构畸形最常见。

Objective To discuss the relationship between nuchal translucency(NT)thickness and fetal structural anomalies in the first trimester.Methods In the first trimester(11 to 13+6 weeks),a total of 6399 singleton pregnant women were examined by ultrasound to measure the thickness of NT.According to the thickness of NT,6399 patients were divided into 5925 patients with NT thickness<3.5 mm(normal NT group)and 474 patients with NT thickness≥3.5 mm(increased NT group).Those confirmed with or without structural anomalies and still willing to continue pregnancy were suggested terminating pregnancy if the fetal anomalies were found on the repeated ultrasound examination and by prenatal test in the second and third trimesters,or continuing pregnancy if the anomalies were non-fatal.The pregnant women continuing pregnancy were followed up for 6 months after delivery.The numbers of pregnancy termination,cessation of fetal development,induction of labor,preterm labor,and term labor were recorded in two groups.The incidences of fetal structural anomalies and the anomalies part were compared between two groups.Increased NT group was redivided into 3.5-<4.5 mm subgroup(n=197),4.5-<5.5 mm subgroup(n=94),5.5-<6.5 mm subgroup(n=55)and≥6.5 mm subgroup(n=128).The incidence of fetal structural anomalies were compared among these subgroups.Results There were 11 cases of fetal development cessation,106 cases of induction of labor,11 cases of premature labor and 5797 cases of term labor in normal NT group,and 6 cases of fetal development cessation,192 cases of induction of labor,3 cases of premature labor and 273 cases of term labor in increased NT group.The incidence of fetal structural anomalies was higher in increased NT group(26.6%)than that in normal NT group(2.4%)(P<0.05),higher in≥6.5 mm subgroup(43.0%)and 5.5-<6.5 mm subgroup(34.5%)than that in 3.5-<4.5 mm subgroup(15.2%),and in≥6.5 mm subgroup than that in 4.5-<5.5 mm subgroup(23.4%)(P<0.05),and showed no significant differences between≥6.5 mm subgroup and 5.5-<6.5 mm subgroup and between 4.5-<5.5 mm subgroup and 3.5-<4.5 mm subgroup(P>0.05).The incidence of cardiovascular anomalies was higher in increased NT group(57.9%)than that in normal NT group(18.7%),and the incidences of central neural system anomalies and abdominal organs anomalies were lower in increased NT group(12.7%,9.5%)than those in normal NT group(32.6%,22.9%).Conclusion Structural anomaly commonly occurs in the fetuses with increased NT in the first trimester,and it increases with the increase of NT thickness.Cardiovascular anomaly is the most common one.