第5周：微小的心脏开始跳动
宝宝现在的大小，相当于 一颗芝麻.
平均长度: 0.2 厘米
（头到臀）
宝宝的发育情况
太神奇了！宝宝小小的心脏管已经开始跳动啦！现在宝宝只有芝麻大小，但胚胎已经分化出三层。神经管（未来发育成大脑和脊髓）正飞速生长。一根原始的脐带也在成型，连接着不断壮大的胎盘。
妈妈的身体变化
月经没来是个大信号，此时体内的 hCG 水平通常足以让早孕试纸显示阳性了！面对喜讯感到既兴奋又忐忑是正常的，有任何担心都欢迎随时咨询医生。随着早孕反应开始，您可能会觉得身体像“感冒”了一样不太对劲。
给伴侣的小贴士
现在是官方盖章的“准爸爸”了，快给她满满的关怀吧！陪她去第一次产检。对了，医生建议准妈妈要远离开猫砂以防弓形虫感染，这可是您表现的重要机会哦，帮她承包这个家务吧。
References
[1]
Fetal Development: Week-by-Week Stages of Pregnancy - Cleveland Clinichttps://my.clevelandclinic.org/health/articles/7247-fetal-development-stages-of-growth
[2]
Fetal development: The first trimester - Mayo Clinichttps://www.mayoclinic.org/healthy-lifestyle/pregnancy-week-by-week/in-depth/prenatal-care/art-20045302#:~:text=The%20embryo%20is%20now%20made,lungs%20and%20intestines%20will%20develop
[3]
The umbilical cord: a rich and ethical stem cell source to advance regenerative medicine - NIHhttps://pmc.ncbi.nlm.nih.gov/articles/PMC6495455/#:~:text=From%20the%20third%20week%20of,shape%20of%20an%20umbilical%20ring
[4]
5 Weeks Pregnant: Baby Development, Symptoms & Signs - What To Expecthttps://www.whattoexpect.com/pregnancy/week-by-week/week-5.aspx#:~:text=It's%20time%20to%20pee%20on,by%20a%20home%20pregnancy%20test
[5]
Week 5 Pregnancy: Your Baby's Heart Starts To Beat - Thomson Medicalhttps://www.thomsonmedical.com/blog/week-5-pregnancy
[6]
Mayo Clinic Minute: Pregnancy and toxoplasmosis - Mayo Clinichttps://newsnetwork.mayoclinic.org/discussion/mayo-clinic-minute-pregnancy-and-toxoplasmosis/