Reasons why pregnant women choose us

NIPT検査

More than 48,000 cases
have been carried out

Hiro Clinic is in cooperation with 67 partner clinics,
performs more than 1,000 examinations per month

World Class Next Generation NIPT

New users here

新規登録

Registered users here

マイーページ

24hours reservation available

Hiro Clinic has conducted more than 48,000 tests from June 2020 to October 2023. In cooperation with the Tokyo Sanitary Laboratory, we have verified the ‘most appropriate test content for pregnant women’.

This data analysis was conducted under the following conditions.

  • No age limit for inspections
    検査年齢制限なし
  • No restrictions on target chromosomes
    対象染色体の制限なし
  • Pregnant women in Japan only
    日本国内の妊婦さん限定

World Class Next Generation NIPT

New users here

新規登録

Registered users here

マイーページ

24hours reservation available

What results are obtained in the absence of the ’35+ age limit’ recommended by the NIPT Consortium? This has not been examined to date.
Of course, the positivity rates for chromosomes 21, 18 and 13 have been reported, but data on all other autosomes (including sex chromosomes) and whole-region partial deletions and duplications have not been reported in Japan.

In NIPT studies worldwide, genetic disorders are known to have ethnic and regional characteristics.
However, despite various research data, mainly from Europe and the USA, but also from Asia, there have been no reports of data on genetic disorders restricted to pregnant women in Japan.

Hiro Clinic NIPT wishes to publish the test results obtained from previous tests and to help pregnant women in their choice of tests. Hiro Clinic NIPT places the utmost importance on protecting the right to know of all concerned parties, including pregnant women.

Total (number)33,670 people
35 years old and over16,175 people48.0%
Under 35 years old17495 people52.0%
Oldest of the positives49 years old
Youngest of the positives22 years old
Number of positive patients895 people2.66%
Positive cases over 35 years old6113.78%
Positive cases under 35 years old2841.62%

According to the latest examination statistics, 48.0% of pregnant women are over 35 years old. This clearly shows that the number of pregnant women under 35 years old being examined is increasing.
In Hiro Clinic NIPT, the overall positive rate is 2.66%; the positive rate for those aged 35 years and over is 3.78%, 2.36 times the positive rate for those under 35 years (1.62%). This is because there are actually around three times more births under the age of 35, so the estimated number of abnormalities under 35 is approximately 1.27 times (= 3 ÷ 2.36) higher than the number of abnormalities over 35. This figure has been increasing, as it was 0.96 times higher when statistics were previously collected. This may be due to the fact that not only trisomy but also partial deletion duplication and microdeletion are age-independent tests and the number of such tests is increasing.

All Positive Locations(Locations)Number of positives (persons)35 years old and over (persons)Under 35 years old (persons)
No. 21 Trisomy25826020355
No. 18 Trisomy15815812632
No. 13 Trisomy49503118
Sex chromosome1381387860
Other autosomes17618510868
Whole autosomal regionPartial deletion
/duplication disease
1161306551
Total895921611284

※Cases with multiple diseases are counted as each disease.

Of those who tested positive, 28.8% had chromosome 21 trisomy, 17.7% had chromosome 18 trisomy and 5.5% had chromosome 13 trisomy, accounting for 52% of the total. On the other hand, aneuploidy (abnormal number of chromosomes) of chromosomes other than chromosomes 13, 18 and 21 accounted for 19.7% of autosomes and 15.4% of sex chromosomes, together accounting for 35% of the total.

Whole-region partial deletions and duplications may have various clinical findings depending on their size and location. However, as the number of whole-region partial deletions and duplications detected by the Hiro Clinic NIPT is more than 7 million bases, even if 2% of these are considered to be in the exonic region, monosomy and trisomy of approximately 140 000 bases are possible, which may lead to some disorders in patients with this disease.

29,269 ‘test coverage’ of NIPT testing (Feb 2023).

Test coverage indicates the percentage of cases that are positive for the selected test plan.

 No. 21No. 18No. 13Sex chromosomeOther autosomesWhole autosomal region
Partial deletion/duplication
Positive Locations 205 Locations 120 Locations 43 Locations 123 Locations 179 Locations 150 Locations
Number of positives 205 people 120 people 43 people 123 people 179 people
29,269人のNIPT検査の「検査カバー率」(2023年2月)

The bar graph above shows the numerical ‘test coverage’ of the test plans that pregnant women often choose at Hiro Clinic NIPT.
If N-Guard O is selected as the test item, the test coverage is 50%, whereas N-Scan B has 87% coverage which is recommended for pregnant women aged 35 and over.
A test coverage of 50% indicates that 50% of diseases are returned negative.
N-Scan F is the most popular plan at Hiro Clinic NIPT. This plan is recommended for those who do not want to miss any results.

Statistical data on over 48,000 cases

Statistics relating to maternal age

受検者の年齢分布グラフ
The mean and median age of examinees is 35.4 and 36.0 years old respectively.
年齢別陽性判定者数(疾患指定なし)グラフ
When looking at the number of positive cases by age, the mode and median are both 42 years old.
陽性判定率の推移(疾患指定なし)グラフ
The positive test rate has increased with increasing age of examination.

Statistics relating to T21

常染色体異数性陽性判定の内訳グラフ
T21: Chromosome 21 trisomy (Down’s syndrome)
T18: Chromosome 18 trisomy
T13: Chromosome 13 trisomy
RAA: aneuploidy of chromosomes 1 to 22 (excluding chromosomes 21, 18 and 13)
陽性判定の内訳(疾患指定なし)グラフ
T21: Chromosome 21 trisomy (Down’s syndrome)
T18: Chromosome 18 trisomy
T13: Chromosome 13 trisomy
RAA: aneuploidy of chromosomes 1 to 22 (excluding chromosomes 21, 18 and 13)
SCA: Sex chromosome aneuploidy
Partial dup/del: partial duplication/underexpression of the whole autosomal region
T21陽性判定率の推移グラフ
The positive test rate is increasing rapidly as the age of the examinee increases.

Statistics relating to T18

T18陽性判定率の推移グラフ
The positive test rate increases with the age of the examinee.

Statistics relating to T13

T13陽性判定率の推移グラフ
The positive test rate increases with the age of the examinee, although there is some variation.