Your 9 months Pregnancy You're 39 weeks pregnant Your are now in the 39th week of your pregnancy and your baby is nearly ready to be born! 1 of Ad break How big is your baby?Your baby’s about the size of a rolling pin, measuring about 38cm crown to rump, and 49cm top to toe. She’ll weigh 3.2kg by the end of the week.Now find out how your baby is growing… How is your baby growing?About 15% of your baby’s body is fat, and all her systems are developed. There’s less amniotic fluid around her now. More antibodies that are needed by your baby’s immune system cross the placenta. The placenta is starting to become less effective in giving your baby nutrients because it’s aging. Meconium – a sticky, greenish-black substance - is collecting your baby’s intestines. This meconium will be your baby’s first poo. Now find out what’s happening to your body… What’s happening to your body?As your contractions begin, you may want to think about what position your baby is in, and how she is ‘presenting’, as this can affect the labour you have. The most usual position is occipito anterior, which is when the baby is head down and curled in a ball. Occipito posterior is when the baby’s head is pushed against the base of your spine, which can cause severe backache throughout labour. The breech position is when the bottom or legs are downwards, and this may mean that you need a caesarean, although it can be done by vaginal birth. Learn more about what symptoms to expect this week and check out our week by week pregnancy guide...Find out what happened in the 38th week of your pregnancy, and what you can expect in your 40th week of pregnancy. By Sara Mackenzie Comments Latest on MadeForMums Princess Marie-Chantal’s touching support for Kate Middleton (Exclusive) Danielle Lloyd's luxury pram pick for baby no 4 Rochelle Humes' divisive method for clearing her baby's bunged up nose Viral wedding invitation tells guests: "Breastfeed in the toilets!"