Your pregnancy is considered full term once you reach the 39th week mark, meaning your baby can arrive any day now . According to a study done by The American College of Obstetricians and Gynecologists, babies born after week 39 have significantly lesser chances of developing any problems with breathing, temperature control and feeding as well as complications like cerebral palsy and sepsis .
Your baby’s brain is still developing rapidly, already being 30% bigger compared to its size four weeks ago . The brain development will continue at the same pace until your baby reaches about 3 years of age.
The growing fat layer is in the final stage of its development, with a thick fat deposit over his blood vessels giving your baby a smooth and chubby appearance. His skin is finally turning whitish from pink, regardless of what color skin he will have later. It will change into the permanent shade during the first years of his life, as the pigmentation starts developing . New skin cells begin to form around this time with the older skin layer sloughing off to be replaced by the developing one underneath .
The endocrine system, responsible for producing hormones, is already preparing for birth as it will produce more stress hormone during the delivery than it is ever going to in the entire life of your baby. These hormones also help to manage the functioning of your baby’s internal organs and systems after birth, when the placenta will no longer be there to help .
Like the brain and nervous system, the lungs also continue to develop until the day your baby is born . During these last few weeks, the lungs are manufacturing surfactant, the chemical substance that makes sure the baby’s air sacs do not stick together as he takes his first breath. In fact, the lungs are usually matured enough by this stage to enable your baby to breathe on his own without any respiratory assistance if he was born this week .
The placenta supplies the baby with antibodies and nutrients from your body to prepare him for fighting diseases and infections outside the womb . He will get even more antibodies after you breastfeed him after birth .
Being 20 inches (50.8 cm) long, he has already achieved the average newborn length by the 39th week . He is now about the size of a small watermelon, weighing around 7.25 pounds (3.29 kg) .
By this time, your baby’s head is probably engaged in the pelvis, ready for delivery; however, it is also normal for babies to engage only after labor starts. After week 37, the baby starts to move down your pelvis, settling in the proper head down birth position. His body may lie straight, in a “longitudinal” position or he may be in an “oblique” position, lying at an angle .
In cases where the baby remains in a breech (feet down) or transverse (lying sideways) position, the doctor might recommend the ECV or external cephalic version to turn him by putting pressure on certain parts of your abdomen . A cesarean section might be scheduled for the 39th week, in cases where the ECV fails to turn the baby, due to the risks of life threatening complications associated with delivering a breech baby vaginally .
Your baby travelling down the abdomen and pelvis may cause your baby bump to drop a little lower . However, dropping of the bump does not necessarily mean that the baby is coming immediately, as most babies engage weeks before the start of labor, especially in first time pregnancies. The baby dropping lower in your abdomen may relieve the symptoms of heartburn, indigestion, chest pain and shortness of breath by allowing more space for the stomach, diaphragm and lungs to stretch.
The doctor will check your blood pressure on every prenatal visit to assess the chances of developing High BP or preeclampsia during the last stage of the third trimester or before delivery . Other routine procedures include fundal measurement and checking your baby’s heartbeat to ascertain proper fetal health.
Your doctor is also likely to perform a cervical exam to see if the cervix has started softening, dilating (open) and effacing (thinning) in preparation of childbirth .
A biophysical profile may be ordered in case of decreased fetal movement detected during kick counts, or a chance of complications like reduced amniotic fluid levels and any placental irregularities . It involves checking the fetal heartbeat and performing an ultrasound scan.
A regular week 39 ultrasound shows your baby look almost exactly as he would on the day of delivery, with fuzzy hair and chubby checks.
As mentioned above, at 39 weeks you are considered full term, meaning the labor can begin anytime now. The earliest signs include:
Doctors prefer letting the baby complete his 40 weeks inside the womb so his organs and systems can mature to the utmost measure before he enters the world. However, there are several instances that might lead your doctor to induce labor. Having a complication like preeclampsia or gestational diabetes, or developing an infectious condition that might be harmful for the baby are some of the reasons for inducing labor . Other causes may include having too little amniotic fluid, breaking your water long before the labor starts as well as other issues like kidney stones.
Castor oil, raspberry leaf tea , evening primrose oil and balsamic vinegar are some of the best known natural measures believed to help induce labor. Pineapples, eggplants and spicy foods are also considered by many to help bring on labor and contractions . However, there is a lack of research based evidence regarding their safety and effectiveness , so it is recommended to consult your doctor before considering these measures.
Published on October 18th 2014 by Pregmed Editorial Team.
Article was last reviewed on 18th October 2014.