Scientists have made a breakthrough in understanding why a foetal blood vessel¹ can fail to close shortly after birth, causing serious health problems.

科学家在理解为什么胎儿在出生后不久血管不能愈合这个问题上取得重大突破，该问题会导致严重的健康问题。

Failure of the vessel to close can lead to serious illness

If the ductus arteriosus动脉导管 fails to close babies develop high blood pressure in the lungs and heart failure心力衰竭.

A German team showed that platelets血小板, cells in the blood which form clots凝块, play a key role in closing the vessel.

The study, by researchers at Munich's Technischen University, appears in the journal Nature Medicine.

The ductus arteriosus is a short vessel which connects the pulmonary artery⁴肺动脉 to the aorta主动脉, allowing most of the blood from the right ventricle右心室 of the heart to bypass the foetus's fluid-filled lungs.

This protects the lungs from being overworked and allows the left ventricle of the heart to strengthen.

However, once development is complete, the vessel's work is done and it usually closes in the hours after birth.

But how this process takes place has been unclear and sometimes it does not happen, causing a condition known as patent ductus arteriosus久存性动脉导管.

This is a particular risk in premature⁶ babies with a low birth weight.

If left uncorrected this can lead to a build up of pressure in the blood vessels⁷ of the lung, which can trigger shortness of breath and dizziness.

Ultimately, it can lead to irregular heart rhythms and congestive heart failure充血性心力衰竭.

Working on mice, the Munich team found that platelets congregate⁸ at the ductus arteriosus during closure, promoting the formation of a clot² as the vessel contracts.

They showed that in mice with defective缺陷 platelet function, the ductus arteriosus failed to close.

This resulted in a condition similar to that found in the human disease: increased blood flow in the lung and excessive growth of the right ventricle of the heart.

Transfusion¹⁰ possibility

The researchers also showed, in a clinical study in premature babies, that not having enough platelets in the blood was associated with a failure of the ductus arteriosus to close.

Lead researcher Dr Steffen Massberg said: "Our study might might lead to a change of the current treatment strategies to prevent failure of ductus arteriosus closure, particularly in preterm newborns with low platelet counts.

"It is conceivable that transfusion of platelets reduces the risk of ductus arteriosus patency明显 (lack of closure) in preterm newborns with low platelet count."

Professor Jeremy Pearson, of the British Heart Foundation, said: "This breakthrough is really promising¹¹ as a better understanding of how the ductus arteriosus closes just after birth could help the treatment of very vulnerable易受伤害的 babies, and potentially save lives."