Nutrition content

1. PREGNANCY, EARLY SIGNS, STAGES
AND KEY PHYSIOLOGIC CHANGES
VND 2201: Maternal, Infant, and Childcare
Ndahura Nicholas Bari
Kyambogo University

2. Pregnancy & some of the early signs
■ The period from conception to birth, after the egg is fertilized by a sperm and the
n implanted in the lining of the uterus.
■ Pregnancy is considered full-term at 40 weeks; infants delivered before the end
of week 37 are considered premature.
■ Pregnancy is measured in trimesters from the first day the last menstrual period,
totalling 40 weeks. The first trimester of pregnancy is week 1 through week 13,
or about 3 months. The second trimester is week 14 to week 26. And the third
trimester of pregnancy spans from week 27 to the birth.

3. Pregnancy & some of the early
signs

4. Pregnancy & some of the early signs
■ In addition to a missed period, the earliest signs and symptoms of pregnancy may include:
– Tender, swollen breasts, nipples darken
– Nausea with or without vomiting, metallic taste in the mouth
– Increased urination, constipation
– Fatigue
– Food aversions or cravings
■ Need to do a pregnancy test to confirm.

5. Stages of pregnancy
■ First trimester
– During the week after fertilization, the fertilized egg grows into a microscopic
ball of cells (blastocyst), which implants on the wall of your uterus. This
implantation triggers a series of hormonal and physical changes in the
woman’s body.
– The third through eighth weeks of growth are called the embryonic stage,
during which the embryo develops most major body organs. During this
process, the embryo is especially vulnerable to damaging substances, such as
alcohol, radiation, and infectious diseases e.g. rubella (German measles).
– Having reached a little more than 1 in. (2.54 cm) in length by the ninth week
of growth, the embryo is called a foetus.
– Also at this stage there is development of placenta, umbilical cord and
amniotic sac.

6. Stages of pregnancy
■ Second trimester
– During this time, the foetus is still building up body fat and starting to put
on a lot of weight. By the end of the second trimester , the foetus is about
10 in. (25.4 cm) long and weighs about 1.5 lb (680 g).
■ Third trimester
– The third trimester of pregnancy spans from week 27 to the birth. Although
the due date marks the end of your 40th week, a full-term pregnancy can
be delivered between week 37 and week 42. During this final trimester, the
foetus grows larger and the body organs mature. At the end of the third
trimester, a foetus usually settles into a head-down position (crowning) in
the uterus.

7. Key physiologic changes that occur
during pregnancy
■ Blood volume and Composition
– Blood volume expands approximately 50% by the end of
pregnancy. This results in decreased haemoglobin, serum
albumin, other serum proteins, and water-soluble vitamins.
– The decline in serum albumin may be the result of fluid
accumulation. The decrease in water-soluble vitamin
concentrations makes determination of an inadequate intake or
a deficient nutrient state difficult. In contrast, serum
concentrations of fat-soluble vitamins and other lipid fractions
such as triglycerides, cholesterol, and free fatty acids increase.

8. Key physiologic changes that occur
during pregnancy
■ Cardiovascular and Pulmonary function
– Increased cardiac output accompanies pregnancy, and cardiac size increases by I2%.
– Diastolic blood pressure decreases during the first two trimesters because of peripheral
vasodilation (dilation of the veins and arteries of the periphery), but returns to pre-
pregnancy values in the third trimester.
– Mild lower extremity edema is a normal condition of pregnancy resulting from the
pressure of the expanding uterus on the inferior vena cava. Blood return to the heart
decreases, leading to decreased cardiac output, a fall in blood pressure, and lower
extremity edema.
– Maternal oxygen requirements increase and the threshold for CO2 lowers, making the
pregnant woman feel shortness of breath (dyspnea). Adding to this feeling of dyspnea is
the growing uterus pushing the diaphragm upward.

9. Key physiologic changes that occur
during pregnancy
■ Gastrointestinal Function
– In the first trimester nausea and vomiting may occur followed by a return of
appetite. Cravings for and aversions to foods are also common.
– Increased progesterone concentrations relax the uterine muscle to allow
for foetal growth while also decreasing GI motility with increased
reabsorption of water. This often results in constipation.
– In addition, a relaxed lower oesophageal sphincter and pressure on the
stomach from the growing uterus can cause regurgitation (the reflex act of ejecting
the contents of the stomach through the mouth) and gastric reflux (backflow of the contents of the
stomach into the oesophagus, caused by relaxation of the lower oesophageal sphincter).

10. Key physiologic changes that occur
during pregnancy
■ Renal Function
– The glomerular filtration rate (GFR) increases by 50 % during pregnancy. Renal
tubular reabsorption is less efficient than in the non-pregnant state, and glucosuria
or glycosuria (excretion of glucose into the urine) may occur, along with increased excretion of
water-soluble vitamins. Small amounts of glycosuria increase the risk for urinary
tract infections.
■ Placenta
– The placenta is the principal site of production for several hormones responsible for
regulating foetal growth and development of maternal support tissues and it is the
conduit for exchange of nutrients, oxygen, and waste products.

11. Key terms
– Primigravida: pregnant for the first time.
– Multigravida: a woman who has been pregnant previously,
regardless of outcome.
– Intrauterine growth restriction (IUGR) refers to poor growth of a
foetus while in the mother's womb during pregnancy. The causes
can be many, but most often involve poor maternal nutrition or
lack of adequate oxygen supply to the foetus.

12. Find out:
■ Rhesus factor
■ ectopic pregnancy
■ Difference between Fraternal (binovular) and identical
(univular) twins
■ The role of the placenta, umbilical cord and amniotic
sac.
■ See link:
https://www.hopkinsmedicine.org/health/wellness-and-