Give scientific reasons: $A$ couple without children can have a child by modern research.

(N/A) Couples who are unable to conceive naturally due to issues such as deficient reproductive organs or an inability to produce viable gametes can have a child through various Assisted Reproductive Technologies $(ART)$.
Commonly used scientific methods include In Vitro Fertilization $(IVF)$,Gamete Intrafallopian Transfer $(GIFT)$,and Zygote Intrafallopian Transfer $(ZIFT)$.
Additionally,surrogacy is another modern method through which parenthood can be achieved.