How much does a baby weigh at 34 weeks pregnant?

Updated July 19, 2017

By 34 weeks of pregnancy the average baby weighs about 2.13 kg and is around 45 cm (18 inches) long. Additionally, layers of fat are now being deposited under the baby's skin that will help maintain and regulate her body temperature after birth, according to As these fat deposits accumulate, her skin becomes smooth and much less wrinkled than it was in weeks past. She now looks much the way she will when she is born.


Even though your due date is just around the corner, your baby's lungs and nervous system still need a few weeks to mature. However, most babies born prematurely during the 34th week of gestation tend to do very well, and may only require a short stay in the neonatal intensive care unit, (NICU), according to The most common problems for preemies of this age include breathing trouble and problems regulating body temperature.

Birth weight

With labour fast approaching many mothers begin to wonder how large their baby will be at birth. It is challenging to accurately gauge your baby's birth weight for many reasons. All babies are different and some factors contribute to babies growing larger than usual, such as gestational diabetes in the mother, while other conditions, including maternal smoking in the mother could restrict a baby's growth, resulting in lower birth weight. Some health care providers will order an ultrasound around 34 weeks to estimate how much the baby weighs. When an ultrasound is used to estimate the weight of the baby they are usually accurate within 220 to 450 g (1/2 to 1lb).

In the womb

By 34 weeks of pregnancy your baby has developmental behaviours similar to that of a newborn. She will suck her fingers or thumb. Her eyes are open during awake times and are closed when she is sleeping. She is aware of sounds around her from both inside and outside the womb, and is already showing a preference for her mother's voice.

Changes in the mother

At this stage of pregnancy a mother has entered her third and final trimester. Fatigue will probably be an issue because of the ever growing belly and weight of the baby, amniotic fluid and placenta. Most mothers complain of the need to frequently urinate that disrupts sleep. Swelling in the feet and ankles may be bothersome as well. Additionally it may be difficult to find a comfortable sleeping position, and some mothers may begin to feel nervous about the prospect of upcoming labour and childbirth.


While babies born at 34 weeks generally do very well and have over a 99 per cent survival rate, it is still important for a mother to seek medical care if she believes she could be in preterm labour. Sometimes labour can be slowed or stopped in order to give the baby a few more days or weeks of development inside the womb, which is critical to the lungs functioning properly.

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About the Author

Emily Weaver has been professionally writing since 2000. She has worked with numerous educational publishers, web magazines, consulting and marketing firms, political campaigns and assorted content production positions. Her work can also be found in various volumes of the "Chicken Soup for The Soul" series. Weaver holds a Bachelor's degree in English as well as creative writing.