The body goes through a lot of changes during pregnancy. As a mom, knowing these 10 physiological changes during pregnancy helped me a lot throughout my journey. These different adaptations enable the accommodation of the developing fetus.
Starting in the first month of pregnancy, a new mom can notice that she is pregnant even before having a pregnancy test due to those changes.
Below we will see various physiological changes in pregnancy:
Hormonal changes
Estrogen and progesterone are the hormones responsible for many changes throughout pregnancy. They adjust the uterus to provide a nutritive and protective environment for the growing fetus.
The uterus will expand to approximately five times its normal size. At 12 weeks of gestation, the uterus may be felt through the abdomen above the pubic bone. The size of the uterus usually reaches its peak at about 36 weeks of gestation.
During the 40th week of pregnancy, the uterus may shrink as the fetal head settles into the pelvis to facilitate delivery.
Wight gain
Continuing weight gain during pregnancy is a positive indicator of maternal adaptation and fetal growth.
Due to continuous nausea and vomiting in some pregnant women, loss of appetite is common; therefore, they will lose weight at early pregnancy stages.
Gradually, new mothers will gain weight due to fetal growth as well as an increase in body fluids.
At the end of pregnancy, the baby weighs about 5 kg, including amniotic fluid. A pregnant woman normally gains between 9 and 12 kg, depending on her pre-pregnancy weight.
Your baby’s health is not determined by your weight.
Increase in heart rate
The heart changes from its previous adaptations due to the increased cardiac demand during pregnancy. It may increase in size due to an increase in its workload.
In early pregnancy, progesterone causes vasodilation so that the uterus stays dilated to maintain pregnancy and causes secondary peripheral vasodilation that leads to about a 30% fall in systemic vascular resistance; therefore, cardiac output increases by around 40% during pregnancy.
Cardiovascular adaptations will cause symptoms like palpitations, decreased exercise tolerance, and dizziness.
Starting at 6–8 weeks of gestation and peaking at 32 weeks, maternal blood volume increases by 40–50% above non-pregnant volumes.
Lower blood pressure is particularly common in early pregnancy due to the progesterone effect, which decreases peripheral resistance. This can cause dizziness and a brief loss of consciousness. Pregnancy can cause an increase in blood pressure, especially if you already have high blood pressure. With a healthy diet and regular exercise, you can prepare your body for pregnancy, which will help you deal with many pregnancy complications.
Respiratory rate
There is an increase in oxygen demand during a normal pregnancy. This is due to the increase in the metabolic rate and the increase in oxygen consumption. The fetus gets the needed oxygen and gives away carbon dioxide through the mother’s placenta.
During pregnancy, the diaphragm elevates by 4 cm due to the enlarged uterus, increasing stress on the lungs. Women cannot breathe as deeply as usual; this is because the growing baby crowds the mother’s lungs as well as all her organs, leaving her with less room to breathe.
Reproductive system changes
During pregnancy, a hormone excreted by the placenta is called human chorionic gonadotropin. It helps thicken a pregnant woman’s uterine lining to support baby growth and tells the body to stop menstruation (although some women will menstruate for a few months while pregnant). An increase in the size of the uterus is associated with an increase in blood supply to the uterus and uterine muscle activity.
The placenta has a major role in connecting the baby to the mother; it helps transfer nutrition and produces hormones as well, like human placental lactogen (chorionic somatomammotropin). It works like human growth hormone. It modifies the metabolic state of the mother during pregnancy to facilitate energy supply to the foetus.
Digestive system disturbance
Nausea and vomiting are very common complaints in early pregnancy due to many causes; the main causes are unknown, but vitamin and mineral deficiency can be one of the causes.
Progesterone causes smooth muscle relaxation, which slows down GI motility and increases constipation risks due to water absorption in the colon, but it also increases the time available for digestion and maximises the absorption of nutrients from the diet.
In the third trimester, an enlarged uterus will cause GI pressure, leading to gastric acid reflux.
A healthy diet, as explained in our previous article, will help reduce symptoms associated with pregnancy.
Urinary tract changes
The increased blood volume and cardiac output due to pregnancy progression cause an increase in renal blood flow. This causes increased excretion and reduced blood levels of urea, creatinine, urate, and bicarbonate.
When the fetus begins to engage in the pelvis in the third trimester, there is an increase in the frequency of urination as the uterus compresses the ureters, causing a slowing of urine flow, which, combined with an increase in urine output, results in frequent trips to the toilet.
Skin changes
Due to hormonal changes, some hyperpigmentations occur in different parts of the body, like the neck, nipples, and abdominal line (linea nigra).
Some pigmentations, such as linea nigra, will be well visible starting at 12–20 weeks of gestation and will disappear 5 months after childbirth.
Posture changes
The weight of the fetus, the enlarged uterus, the placenta, and the amniotic fluid put a large strain on the woman’s bones and muscles. Sitting or standing for too long can cause a lot of problems, especially if you are going to travel long distances. Try to wear pregnant compression socks.
Breast changes
Breasts start to increase in size as pregnancy progresses; the surface blood vessels of the breast may become visible like a network of blood vessels due to the increase in circulation, and this may give the breasts a bluish tint. During the second trimester, the breasts begin to produce colostrum. This is the precursor to breastmilk. After the baby is born, colostrum is produced for about the first three days before the proper milk begins to flow.
How to prepare for breastfeeding
The mother’s body goes through different changes; those changes facilitate the baby’s growth and provide the needed nutrients. The fetus will not grow as large as in the later stages of pregnancy, but his nervous system will develop rapidly, so eating a variety of healthy foods will help your body be healthier and ensure that the baby gets what he needs.
