Yuning Zhu1, Shiming Lu2, Xuming Bian3, He Wang4, Baosheng Zhu5, Hua Wang6, Zhengfeng Xu7, Liangpu Xu8, Weihua Yan9, Yan Zeng10, Zhiyang Chen11, Shaohua Tang12, Guosong Shen13, Zhengyou Miao14. 1. Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, China; Prenatal Diagnosis Center of Zhejiang Province, Hangzhou, China. 2. Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, China; Prenatal Diagnosis Center of Zhejiang Province, Hangzhou, China. Electronic address: lushiminghz@163.com. 3. Department of Obstetrics and Gynecology, Academy of Medical Science, Chinese Peking Union Medical College, Peking Union Medical College Hospital, Beijing, China. 4. West China Second University Hospital, Sichuan University, Prenatal Diagnosis Center of Sichuan Province, Chengdu, China. 5. Genetic Diagnostic Center, the First People's Hospital of Yunnan Province, Kunming, China. 6. The Maternal and Child Health Hospital of Hunan Province, Prenatal Diagnosis Center of Hunan Province, Changsha, Hunan, China. 7. Center of Prenatal Diagnosis, Nanjing Maternity and Child Health Care Hospital, Nanjing, China. 8. Center of Prenatal Diagnosis, Maternal and Child Health Hospital of Fujian Province, Fuzhou, China. 9. Center of Prenatal Diagnosis, Taizhou Hospital, Taizhou, China. 10. Center of Prenatal Diagnosis, Shaoxing Maternity and Child Health Care Hospital, Shaoxing, China. 11. Center of Prenatal Diagnosis, Ningbo Maternity and Child Health Care Hospital, Ningbo, China. 12. Center of Prenatal Diagnosis, Wenzhou Central Hospital, Wenzhou, China. 13. Center of Prenatal Diagnosis, Huzhou Maternity and Child Health Care Hospital, Huzhou, China. 14. Center of Prenatal Diagnosis, Jiaxing Maternity and Child Health Care Hospital, Jiaxing, China.
Abstract
OBJECTIVE: This study aimed to determine the rates of different fetal chromosomal abnormalities among women of advanced maternal age in China and to discuss the possible misdiagnosis risks of newer molecular techniques, for selection of appropriate prenatal screening and diagnostic technologies. MATERIALS AND METHODS: Second trimester amniocentesis and fetal karyotype results of 46,258 women were retrospectively reviewed. All women were ≥ 35 years old with singleton pregnancies. The rates of clinically significant chromosomal abnormalities (CSCAs), incidence of chromosomal abnormalities, and correlations with age were determined. RESULTS: From 2001 to 2010, the proportion of women of advanced maternal age undergoing prenatal diagnosis increased from 20% to 46%. The mean age was 37.4 years (range, 35-46 years). A total of 708 cases of CSCAs, with a rate of 1.53% were found. Trisomy 21 was the most common single chromosome abnormality and accounted for 55.9% of all CSCAs with an incidence of 0.86%. Trisomy 13, trisomy 18, and trisomy 21, the most common chromosome autosomal aneuploidies, accounted for 73.6% of all CSCAs, with a rate of 1.13%. As a group, the most common chromosomal aneuploidies (13/18/21/X/Y) accounted for 93.9% of all abnormalities, with a rate of 1.44%. The incidence of trisomy 21, trisomy 13/18/21 as a group, and 13/18/21/X/Y as a group was significantly greater in women aged 39 years and older (p < 0.001), but was not different between women aged 35 years, 36 years, 37 years, and 38 years. CONCLUSION: These findings may assist in genetic counseling of advanced maternal age pregnant women, and provide a basis for the selection of prenatal screening and diagnostic technologies.
OBJECTIVE: This study aimed to determine the rates of different fetal chromosomal abnormalities among women of advanced maternal age in China and to discuss the possible misdiagnosis risks of newer molecular techniques, for selection of appropriate prenatal screening and diagnostic technologies. MATERIALS AND METHODS: Second trimester amniocentesis and fetal karyotype results of 46,258 women were retrospectively reviewed. All women were ≥ 35 years old with singleton pregnancies. The rates of clinically significant chromosomal abnormalities (CSCAs), incidence of chromosomal abnormalities, and correlations with age were determined. RESULTS: From 2001 to 2010, the proportion of women of advanced maternal age undergoing prenatal diagnosis increased from 20% to 46%. The mean age was 37.4 years (range, 35-46 years). A total of 708 cases of CSCAs, with a rate of 1.53% were found. Trisomy 21 was the most common single chromosome abnormality and accounted for 55.9% of all CSCAs with an incidence of 0.86%. Trisomy 13, trisomy 18, and trisomy 21, the most common chromosome autosomal aneuploidies, accounted for 73.6% of all CSCAs, with a rate of 1.13%. As a group, the most common chromosomal aneuploidies (13/18/21/X/Y) accounted for 93.9% of all abnormalities, with a rate of 1.44%. The incidence of trisomy 21, trisomy 13/18/21 as a group, and 13/18/21/X/Y as a group was significantly greater in women aged 39 years and older (p < 0.001), but was not different between women aged 35 years, 36 years, 37 years, and 38 years. CONCLUSION: These findings may assist in genetic counseling of advanced maternal age pregnant women, and provide a basis for the selection of prenatal screening and diagnostic technologies.