All the changes in the womb are paying off. Baby now looks like a human and can weigh up to 8 ounces. Bowel development continues and the first bowel movement, meconium, is developing inside. Baby will not pass the first movement until after birth, in most cases. The fingers and toes are developing pads and soon fingerprints will form. The boy fetus is developing the prostate gland during week 18 of pregnancy.
Small, rhythmic movements of the stomach may be noticed at this time. These movements are like exercises for the fetus – but pregnant women may know them better as hiccups.
Dizziness and lightheadedness may continue to be a problem during the 18th week. Blood volume increases can cause a lag in the cardiovascular system, which leads to these symptoms. Some pregnant women find walking with a cane helpful to maintain balance.
An ultrasound is commonly scheduled between the 18th and 20th week – if one has not already been performed. Fetal sex may be determined during the ultrasound as well as measurements of the arms, legs, head and abdomen. These measurements are used to determine fetal age and estimate a more realistic date of delivery.
Emotional mood swings are going to be a problem throughout the pregnancy. If the expectant father tries to solve every problem, he may find himself running in circles. Offering a shoulder to lean on when she is feeling down is the best solution to all those fluctuating emotions.
Finding out the baby’s sex is an exciting part of pregnancy, but both parents need to remember that ultrasound technology is not a perfect science. Unless an amniocentesis was performed and sex determined based on chromosomes, the guess is just a guess, or better, it's a very, very educated guess. Identifying the fetal sex on ultrasound can be over 99% accurate, but it's never 100%. Planning a baby room all in pink may backfire if that guess is wrong.
Ultrasounds pose no threat to baby. Sounds are bounced off the fetus and a picture results. A gel-like liquid is placed on the belly to advocate a better reception, if you will. It is important not to use the bathroom right before an ultrasound as a full bladder will bring the uterus closer to the surface of the skin.