BI1S203 Human Growth & Development - Maternal Physiological Adaptations in Human Pregnancy

Vocabulary flashcards covering key terms and definitions related to maternal physiological adaptations during pregnancy.

Uterus

Expands from a strictly pelvic organ before 12 weeks to become an abdominal organ for the remainder of gestation; Weight increases from 60g to 1000g; Increases in size from 6.5cm to 32cm

Cervix during Pregnancy

During pregnancy, the cervix is closed; a mucus plug forms providing a protective barrier between the vagina and the uterine contents.

Placenta

Highly specialised organ of pregnancy that supports the normal growth and development of the fetus; Circular disc with a diameter of 15 – 20 cm

Fetal Membranes

Amnion and Chorion membranes form the amniotic sac that surrounds and protects the fetus.

Amnion Function

Dominates the mechanical behaviour of the fetal membranes and acts as a structural barrier

Chorion Function

Acts as an immunological buffer preventing degradation of the amnion and protecting the fetus from the maternal immune system.

Decidua Basalis

Former endometrium – Decidualisation; underlines the implantation site & takes part in placenta formation.

Endocrine Shift

Transfer of function from the corpus luteum to the placenta at 6-8 weeks.

Prolactin

Hormone that promotes milk secretion; secreted from the pituitary gland.

Mammogenesis

Preparation of the breast for lactation.

Lactogenesis

Synthesis & secretion of milk.

Galactokinesis

Ejection of milk.

Galactopoiesis

Maintenance of lactation.

Involution

Termination of lactation.

Relaxin

Secreted by the ovaries and placenta; main function is to “relax” the ligaments & muscles leading to increased flexibility.

Pituitary Gland during Pregnancy

Enlarges during pregnancy due to proliferation of prolactin-producing cells in anterior lobe; FSH & LH are undetectable.

Heart during Pregnancy

Muscle, particularly the left ventricles, hypertrophies leading to enlargement of the heart.

Cardiac Output during Pregnancy

Gradually increases during the first 2 trimesters, reaching 50% above pre-pregnancy levels by week 16 – 20.

Blood Volume during Pregnancy

Total blood volume increases by about 1.5 liters mainly to supply the demands of the new vascular bed and to compensate for blood loss during birth.

Platelets during Pregnancy

Decreases during pregnancy, particularly in the 3rd trimester, due to hemodilution and increases platelet activation and accelerated clearance.

White Blood Cells during Pregnancy

Increases during pregnancy due to physiologic stress induced by the pregnant state.

Immune tolerance in pregnancy

Absence of maternal immune response against the fetus and placenta.

Placenta Immunological Role

The placenta functions as an immunological barrier between mother and fetus.

Inflammation in Pregnancy

Normal pregnancy associated with maternal low grade systemic inflammation.

Ligaments during Pregnancy

Relaxin causes pelvic ligaments and the pubic symphysis to relax, widen and become more flexible, increasing motility to ease birth passage.

Center of Gravity during Pregnancy

Increasing bulkiness of the abdomen changes the woman’s center of gravity forward, increasing the stress on the joint and causes the back to curve.

Parturition

Labour/act of giving birth.

Carbohydrate Metabolism during Pregnancy

Diabetogenic; increased insulin secretion + sensitivity (1st trimester) leading to progressive insulin resistance (2nd & 3rd trimester).

Kidney Function during Pregnancy

Increased elimination of sugars, amino acids & creatinine.

Skin during Pregnancy

Stretches to accommodate the growing uterus and breast tissue causing stretch marks; increased estrogen increases melanin production.