Pregnancy Week By Week - Symptoms, Ultrasound, Weight Gain

The different stages of pregnancy as per the three trimesters are detailed below.

The First Trimester

It begins in the first week of pregnancy and ends after 12 weeks.

The Mother: Doctors calculate the due date from the first day of the last period. This includes the menstrual cycle and the process of egg fertilization. After fertilization, the egg clings to the uterine wall and undergoes the process of cell division and multiplication. Women may elicit implantation bleeding, frequent urination, and increased fatigue after about a week into pregnancy. A urine test gives a positive result of pregnancy due to the occurrence of pregnancy hormones secreted by the body that gets eliminated with urine.
The Baby: From a solitary cell, the baby grows to nearly 150 cells measuring only 0.014 to 0.04 inches. The different cells are categorized into three layers, with the outermost layer developing into the nervous system, skin and hair; the middle layer developing into muscles, kidneys, sex organs, cartilage, skeleton, bones, and the circulatory system; while the final layer develops into the digestive and respiratory systems.

The Baby:The length of the fetus ranges between 0.56 to 0.8 inches. Different organs such as the pancreas, appendix, nervous system, digestive system, muscles, brain, spinal cord, heart, placenta, and amniotic sac have started forming. Doctors can detect facial features like the nose and eyelids as well as the heartbeat through an ultrasound. The fetus has also started taking nutrients from the umbilical cord.
The Mother:It is a confirmed pregnancy and accompanying symptoms such as morning sickness, breasts soreness, darkening of areola, etc., are easily noticeable. Mothers may gain some weight, typically in the legs and breasts. The uterus may enlarge causing cramps and pain in lower back.

The Baby: The fetus may measure nearly 2.5 inches in length. The fingers and genitals may undergo rapid growth, while the eyes and ears may grow at a gradual pace. An ultrasound may be able to detect certain movements of the baby. All major developments may complete after a month, and after the 12^th week, the risk to miscarriage is over.
The Mother: There is waning of the first symptoms of pregnancy. Some expectant women may continue experiencing food repulsions and cravings. The expanding uterus may expand the waistline, but it is still not that evident. Mothers may gain about three to five pounds after 12 weeks of pregnancy.

: It begins in the 13^thweek of pregnancy and ends after 28 weeks. By this stage, the child is not subject to any kind of danger.

The Baby:The baby is about 4.3 to 4.6 inches big. The process of bones, muscles, skin, and the full skeleton formation commences. The first bowel movement of the developing baby is deposited as meconium in the intestine. Ocular development and formation of other glands lead to a more human-like appearance. The baby has also started oral sucking actions and reacting to external stimulus.
The Mother:The uterus weighs nearly 8.75 ounces after 16 weeks of pregnancy. The enlarged uterus may cause an increased desire to frequently pass urine, as well as constipation. The excess body weight may also result in lower back pain and stretching of muscles. Increased blood circulation may sometimes cause nose bleeds.

The Baby:The baby is nearly 6 inches long and almost 50 percent formed. The skin elicits a layer of fine hair as well as a waxy covering called varnix for added protection. The nails begin growing and the baby is able to hear sounds, like the heartbeats and voice of the mother. The baby can also cover its ears with its hands and thus avoid exposure to harsh or loud sounds.
The Mother: Mothers may put on lots and lots of weight; they may require long, hard, and deep breaths; and they may experience elevated heart beats as well as excessive perspiration. The increase in the size of the uterus and belly is what finally causes elevated fatigue, exhaustion, and constipation.

The Baby:The baby is about 8.4 inches long. Red and white blood cells for countering infections as well as teeth buds have started forming. The baby is able to respond to the voices that it hears. It can also identify these same voices after delivery.
The Mother: Expectant women will continue to gain weight and experience enlargement of the belly, muscle cramps and pain. Sometimes, they may experience a yellowish, smelly vaginal discharge.

The Baby: The baby measures nearly 10 inches. It has fully developed ears and the right REM sleep patterns. The baby commences thumb sucking activity and elicits a distinctive sleeping and waking pattern. The heartbeat is easily audible through a stethoscope. The lungs are almost fully developed.
The Mother: There is rapid growth of the belly and the mother will gain nearly 1 pound per week. Back aches, leg pain, frequent urination, and swelling of the area next to the ankles persist. Stretch marks are also clearly visible. After 28 weeks of pregnancy, sleeping problems arise.

It is the last and final trimester of pregnancy, which can persist till the fortieth week.

The Baby:The baby measures about 18.9 inches, from head to the toe. It may often open its eyes and gauge the difference between dim and bright lights. Full eyebrows and eyelashes, and thicker hair is present. The baby continuously gains fat and becomes healthier.
The Mother:There is continuance of constipation, back aches, elevated vaginal discharge, and leg pain. The breasts may secrete a yellowish fluid signaling the readiness of the body to nourish the baby.

The Baby: The baby is nearly 20.7 inches big and weighs about six pounds. It can blink its eyes. The lungs are fully formed and the brain continues developing rapidly. The baby now takes up all available space in the uterine cavity, thereby limiting its range of motion.
The Mother:The ginormous belly exerts extreme pressure on the pelvis, rib cage, and navel, leading to pain. Such distress can result in sleeping problems like amnesia or partial sleep. The uterus starts its preparation for childbirth.

The Baby:The completely mature baby is about 21.5 inches long, from the head to the toe. The head tilts towards the pelvis for the ideal position for birth. Response to light, sounds, and other stimuli; movement of lungs, blinking of the eyes, etc. are observable.
The Mother:Mothers may experience heartburn, severe back pain, nausea, and sleeplessness on a daily basis. Comfort of sleepmay not be possible, but mothers need to take sufficient rest. It is possible for labor pain to occur anytime at this stage.