Your baby is shedding the greasy, white substance (vernix caseosa) which has been protecting his skin. This turns the amniotic fluid, which was once clear, pale and milky. The outer layers of your baby's skin are also sloughing off as new skin forms underneath.
The hair on your baby's head may now be thick, and his fingernails extend beyond his fingertips. They may look long when he's born. Your baby's skull bones are not yet fused, which allows them to overlap as he passes through the birth canal during labour. This is the reason your baby's head may look cone-shaped after birth.
And if the week passes and there's still no baby? Try not to worry – babies have a habit of not arriving on their scheduled due date. Most doctors wait another two weeks before considering a pregnancy overdue. Check out how to cope with being overdue.
Note: Every baby develops differently. This page is designed to give a general idea of how a fetus grows in the uterus.
See your previous stage: 38 weeks pregnant
See your next stage: 40 weeks pregnant
Last reviewed: August 2009
ReferencesThis article was written using the following sources:
Hill M. 2009. Development week by week. University of New South Wales Embryology. embryology.med.unsw.edu.au [Accessed August 2009]
McLean F, Usher R. 1969. Intrauterine growth of live-born Caucasian infants at sea level: Standards obtained from measurements in 7 dimensions of infants born between 25 and 44 weeks of gestation. Pediatrics 74(6):901-10
Medline. 2009. Fetal development. Medline Plus Medical Encyclopedia. www.nlm.nih.gov [Accessed August 2009]
Visembryo. 2006. Pregnancy timeline. The Visible Embryo. www.visembryo.com [Accessed August 2009]