34 weeks pregnant: fetal development

Medically reviewed by Joseph Aquilina, Consultant obstetrician and gynaecologist

Your baby is the size of a rockmelon (cantaloupe). She weighs more than 2.1kg and is about 45cm from head (crown) to heel (Hill 2019).

It's reassuring to know that babies who are born at 34 weeks, who have no other health problems, are able to thrive outside the uterus (womb) (Moore et al 2019, Tommy's nd). If your baby is born this week, she may need a little help in the neonatal unit, but after that she'll be all set to do as well as if she'd arrived full-term (Tommy's 2016).

Advertisement | page continues below

Your baby is continuing to fill out. She has been laying down a special type of fat, called brown fat (Lubkowska et al 2019, Waldron and MacKinnon 2007). This helps her keep warm after she's born, because newborn babies can't regulate their core body temperatures very well (England 2014, Lidell 2019, Waldron and MacKinnon 2007). Brown fat stops growing after birth, and your baby will need you to make sure she has the right number of layers so she doesn't get too hot or cold (Lubkowska et al 2019, Waldron and MacKinnon 2007). Your midwife will guide you about how to keep your new baby cosy (England 2014).

Your baby already knows your voice and your partner's voice (Dunn et al 2015, Ferrari et al 2016, Lee and Kisilevsky 2014). It may now be possible for her to recognise lullabies and songs, too (Ullal-Gupta et al 2013). This is because the part of her ear that sends messages to her brain (cochlea) is becoming more mature (Granier-Deferre et al 2011).

Research shows that if you regularly sing a particular song to your baby before she's born, she's more likely to be soothed when you sing it again after birth (Brandt et al 2012, Ullal-Gupta et al 2013). Singing to your bump is a great way to bond with your unborn baby, too.

Discover how pregnancy can affect your body and your life at 34 weeks pregnant.

VIDEO

Note: Every baby develops differently. This page is designed to give you a general idea of how a fetus grows in the uterus.

<< 33 weeks

35 weeks >>

Advertisement | page continues below

Was this article helpful?

Yes

Track your pregnancy on our free #1 pregnancy & baby app

Sources

BabyCenter's editorial team is committed to providing the most helpful and trustworthy pregnancy and parenting information in the world. When creating and updating content, we rely on credible sources: respected health organisations, professional groups of doctors and other experts, and published studies in peer-reviewed journals. We believe you should always know the source of the information you're seeing. Learn more about our editorial and medical review policies.

Brandt A, Gebrian M, Slevc LR. 2012. Music and early language acquisition. Front Psychol 3:327

Dunn K, Reissland N, Reid VM. 2015. The functional foetal brain: A systematic preview of methodological factors in reporting foetal visual and auditory capacity. Dev Cogn Neurosci 13:43-52

England C. 2014. Recognizing the healthy baby at term through examination of the newborn screening. In: Marshall J, Raynor M. eds. Myles textbook for midwives. 16th ed. Edinburgh: Churchill Livingstone, 143-77

Ferrari GA, Nicolini Y, Demuru E, et al. 2016. Ultrasonographic investigation of human fetus responses to maternal communicative and non-communicative stimuli. Front Psychol 7:354

Granier-Deferre C, Bassereau S, Ribeiro A, et al. 2011. A melodic contour repeatedly experienced by human near-term fetuses elicits a profound cardiac reaction one month after birth. PLoS One 6(2):e17304

Hill MA. 2019. Fetal development. University of New South Wales, Embryology. embryology.med.unsw.ed.auOpens a new window [Accessed April 2020]

Lee GY, Kisilevsky BS. 2014. Fetuses respond to father's voice but prefer mother's voice after birth. Dev Psychobiol 56(1):1-11

Lidell. 2019. Brown adipose tissue in human infants. Handb Exp Pharmacol 251:107-23

Lubkowska A, Szymański S, Chudecka M. 2019. Surface body temperature of full-term, healthy newborns immediately after birth – pilot study. Int J Environ Res Public Health 16:1312

Moore KL, Persaud TVN, Torchia MG. 2019. Fetal period: ninth week to birth. Chapter 6 in The developing human: clinically oriented embryology. 11th ed. Elsevier

Tommy's. 2016. Gestational age and medical needs. www.tommys.orgOpens a new window [Accessed April 2020]

Tommy's. nd. Premature birth statistics. www.tommys.orgOpens a new window [Accessed April 2020]

Ullal-Gupta S, Vanden Bosch der Nederlanden CM, Tichko P, et al. 2013. Linking prenatal experience to the emerging musical mind. Front Syst Neurosci 7:48

Waldron S, MacKinnon R. 2007. Neonatal thermoregulation. Thermoregulation 3(3):101-4

Megan Rive

Megan Rive is a communication, content strategy and project delivery specialist. She was Babycenter editor for six years.

Opens a new window Opens a new window Opens a new window