Presentation on theme: "Physiology & Psychology Maternal physiological adaptations to pregnancy The placenta Psychosocial adaptations."— Presentation transcript:
Physiology & Psychology Maternal physiological adaptations to pregnancy The placenta Psychosocial adaptations
Physiology of Pregnancy Goals: 1) Healthy mother 2) Appropriately grown, healthy fetus with low risk for adult disease
Systematic Adjustments to Pregnancy Cardiovascular Respiratory Renal GI
Cardiovascular Adaptations Heart rate increases –10-20% –Begins as early as 5 weeks –Peaks by 32 weeks Stoke volume increases –25-30% –Peeks at 16-24 weeks Systemic Vascular Resistance decreases –20% –As early as 5 weeks –Result of vascular smooth muscle relaxation –Allows changes in cardiac output without increase in arterial pressure
Cardiac output during three stages of gestation, labor, and immediately postpartum compared with values of nonpregnant women. All values were determined with women in the lateral recumbent position.
Respiratory Adaptations 30% increased production of CO 2 50% increase volume air and gas exchange Increase in lung volume Decreased airway resistance
Renal Function Changes Renal blood flow –Increases 50-80% by end of 1 st trimester –Decreases gradually to term Glomerular filtration rate –Increases 40-50% –Begins at 5 weeks, peaks at 9-16 weeks –May decrease 15-20% from 36 weeks to term
Mean glomerular filtration rate in healthy women over a short period with infused inulin (solid line), simultaneously as creatinine clearance during the inulin infusion (broken line), and over 24 hours as endogenous creatinine clearance (dotted line).
GI Adaptations Anatomic – growing uterus Hormonal –Progesterone – relaxation of GI smooth muscle –Estrogen – increased tissue vascularity
Adjustments in Nutrient Metabolism Goals –support changes in anatomy and physiology of mother –support fetal growth and development –maintain maternal homeostasis –prepare for lactation Adjustments are complex and evolve throughout pregnancy
General Concepts 1. Alterations include: increased intestinal absorption reduced excretion by kidney or GI tract 2. Alterations are driven by: hormonal changes fetal demands maternal nutrient supply
3. There may be more than one adjustment for each nutrient. 4. Maternal behavioral changes augment physiologic adjustments. 5. When adjustment limits are exceeded, fetal growth and development are impaired.
Birth weight of 11 children born to a poor woman in Montreal; 8 children were born before receiving nutritional counseling and food supplements from the Montreal Diet Dispensary and 3 children were born afterward.
6. The first half of pregnancy is a time of preparation for the demands of rapid fetal growth in the second half.
7. Alterations in maternal physiology facilitate transfer of nutrients to the fetus.
Nitrogen Balance (g/day)
Hormonal Adjustments Changes in over 30 different hormones have been detected in pregnancy Estrogens: increase significantly in pregnancy, influence carbohydrate, lipid, and bone metabolism Progesterone: relaxes smooth muscle and causes atony of GI and urinary tract Human Placental Lactogen (hPL): stimulates maternal metabolism, increases insulin resistance, aids glucose transport across placenta, stimulates breast development
Late gestation is characterized by: –Anti-insulinogenic and lipolytic effects of Human chorionic somatomammotropin, prolactin, cortisol, glucagon Which Results in: –Glucose intolerance, insulin resistance, decreased hepatic glycogen, mobilization of adipose tissue
Non pregnant Early pregnancy Late pregnancy Total triglycerides6075 to 100210 Total cholesterol170175 to 200250 VLDL cholesterol10 25 LDL cholesterol105100 to 125150 HDL cholesterol5555 to 7565 Lipids
Maternal Plasma volume increases ~ 40% range 30-50% nutrient concentration declines due to increased volume, but total amount of vitamins and minerals in circulation actually increases.
Mean hemoglobin concentrations ( — ) and 5th and 95th ( — ) percentiles for healthy pregnant women taking iron supplements
Embryonic and Placental Development http://www.youtube.com/watch?v=UgT5rU Q9EmQhttp://www.youtube.com/watch?v=UgT5rU Q9EmQ http://www.youtube.com/watch?v=jo3NjAp FSQEhttp://www.youtube.com/watch?v=jo3NjAp FSQE http://www.youtube.com/watch?v=YJL9roi 1LbM&feature=relatedhttp://www.youtube.com/watch?v=YJL9roi 1LbM&feature=related
Embryonic Development In early gestation Embryo is nourished by secretions of the oviduct and uterine endometrial glands Uterine secretions include growth factors (e.g. TNF , epidermal growth factor) that promote placental growth Growth trajectories of both placenta and fetus are established early & have lifelong consequences
Nutrient Availability & Maternal Metabolic Status Blastocyst development & implantation are reduced –diabetic mothers –animal models with insufficient nutrients Poorly nourished women and obese women at risk for aberrations in embryonic and placental development –Congenital anomalies –Adverse outcomes later in pregnancy (e.g. preeclampsia)
The Placenta 10-12 weeks is the period of placentation Rapid early growth prepares way for fetal growth Trophoblast cells use same molecular mechanisms as tumors, but are highly regulated and controlled
Placental Functions Maintains immunological distance between mother and fetus Special endocrine organ: “transient hypothalamo-pituitary-gonadal axis” Responsible for exchange of nutrients, gases & metabolic waste products between maternal and fetal circulation
Placental Architecture Maternal and fetal blood do not mix: “placental barrier” –Fetal blood flows through capillary networks within highly branched terminal chorionic villi –Maternal blood flows through intervillous space Uterine arteriols bring blood in Uterine venules drain blood
Placental Capacity Increases During Gestation Expression of transporters increases The “brush border” microvilli develop to: –increase surface area –impede maternal blood flow Flow through the placenta at term is 500 ml/minute
Mechanisms of Nutrient Transfer Across the Placenta
Maternal to Infant Nutrient Transportation Across The Placenta
Fetal to Maternal Transport Carbon dioxide Water & urea Signaling Molecules: Hormones, cytokines, others
Factors Affecting Placental Transfer Placental size Diffusion distance – –diabetes and infection cause edema of the villi –distance decreases as pregnancy progresses and fetal needs increase Maternal-placental blood flow Blood saturation with gases and nutrients
Factors Affecting Placental Transfer (cont) Maternal-placental metabolism of the substance Disorders in expression or activity of nutrient transporters Maternal use of tobacco, cocaine, alcohol
Metabolic Functions of the Placenta Glycogen synthesis: from maternal glucose & stored Cholesterol synthesis: placental cholesterol is precursor for placental progesterone and estrogens Protein production: rises to 7.5 g per day at term Lactate: produced in large quantities and needs to be removed
Endocrine Functions Placenta Produces Peptide hormones –Human Chorionic gonodotrophin (hCG) - secreted early and helps to maintain synthesis of progesterone –Human placental lactogen (hPL): increase supply of glucose to future by decreasing maternal stores of fatty acids by altering maternal secretion of insulin –Insulin-like growth factors (IGF): IGF signaling system is a major regulator of growth in fetus and infant
Endocrine Functions Steroid hormones –Progesterone: produced by placenta, needed to maintain non-contractile uterus –Estrogen: produced by placenta drives many processes in pregnancy Glucocorticoids: placenta regulates fetal exposure
Emerging Understandings Cytokines & Inflammatory molecules are produced by the placenta as well as adipocytes Adverse outcomes in obese women may be associated with imbalances due to overproduction from both sources “In pregnancy complicated with obesity or DM, continuous adverse stimulus is associated with dysregulation of metabolic, vasular and inflammatory pathways.”
The Known and Unknown of Leptin in Pregnancy (Hauguel-de-Mouzon, Am J Obstet Gynecology, 2006) Maternal plasma leptin levels rise in pregnancy Leptin is produced by placenta Overproduction of placental leptin is seen with diabetes and htn in pregnancy Umbilical leptin levels are biomarker of fetal adiposity “Leptin may be sensitive to maternal energy status and coordinate metabolic response accordingly.” (King, Ann Rev Nutr, 2006)
Maternal Undernutrition Influences Placental-Fetal Development (Belkacemi et al. Bio Repro. 2010) What nutritional factors are associated with placental “plasticity?” What are the long term impacts of placental insufficiency? What are the implications for practice?
Psychology of Pregnancy Psychosocial adaptation –Process over time –Prerequisite for developing parental identify and behavior Factors that impact psychosocial adaptation –Pregnancy intendedness –Stress & depression
Why do we care in terms of nutrition? Stress interferes with ability to achieve developmental tasks Developmental tasks key to ability of mother to take care of herself and her baby nutritionally.
Maternal Focus Trimester 1 I’ m pregnant! 2 There’s a BABY ….. 3I’m going to be a MOM
Developmental Tasks of Pregnancy (Rubin, 1984) Seeking safe passage for herself and her child through pregnancy, labor, and delivery. Ensuring the acceptance by significant persons in her family of the child she bears. Binding-in to her unknown baby. Learning to give of herself.
Ensuring Safe Passage Care and knowledge seeking behaviors Concerns –T1: own well-being –T2: focus shifts to fetus/baby –T3: surviving labor and birth Goal: personal survival and safe birth of healthy baby
Seeking Acceptance/Support for Self and Baby Re-defining relationships with –Spouse/partner –Family of origin –Friends –New social support networks Goal: ensure a place in the world for herself, as a woman with a child, and her baby
“Binding-in” to Unborn Child Attachment to fetus Process: –Begins in childhood –Intensifies in pregnancy with fantasizing about unborn infant –Well developed relationship by T3 –Birth – let go of being pregnant & adjusts to being mother –Integrates real baby Goal: maternal identity development
Giving of Oneself Willingness & ability to make personal sacrifices for well-being of fetus/infant Goal: insure baby’s future well-being
What about Dad? Psychosocial and mental health issues for new fathers. (Condon, 2006. The Australian First Time Fathers Study) Tasks: 1.Developing an attachment to the fetus 2.Adjusting to the dyad becoming a triad 3.Conceptualizing the self as “father” 4.What type of father?
Unintended Pregnancy At the time you became pregnant, did you want to become pregnant then, did you want to wait until later, or did you want no (more) children at all?
Births from Unintended Pregnancy in WA State (PRAMS) 200020072010 Medicaid565451 Non-Medicaid262223 Total3836 http://www.doh.wa.gov/Portals/1/Documents/Pubs/950- 153_PerinatalIndicatorsforWashingtonResidents.pdfhttp://www.doh.wa.gov/Portals/1/Documents/Pubs/950- 153_PerinatalIndicatorsforWashingtonResidents.pdf, May 2012
Effects of pregnancy planning status on birth outcomes and infant care (Kost et al. Family Planning Perspectives, 1998)
Prevalence of Self-Reported Postpartum Depressive Symptoms. MMWR, April 2008 Overall prevalence ranged from 12-20% in states. Characteristics associated with PDS: Maternal age Marital status Maternal education, medicaide coverage
WA State Post-Partum Depression 2008: ~9% of mothers reported always or often feeling down, depressed or hopeless, 10% reported always or often having little interest or pleasure in doing things (two questions combined identify subjects at higher risk for post partum depression). 2008: 13% of women expressed experiencing postpartum depression symptoms. More women on Medicaid reported symptoms than women who did not receive Medicaid. 2010:11% of women expressed feeling down, depressed or sad. More women on Medicaid (14%) reported symptoms than women who did not receive Medicaid (8%). http://www.doh.wa.gov/Portals/1/Documents/Pubs/950- 153_PerinatalIndicatorsforWashingtonResidents.pdfhttp://www.doh.wa.gov/Portals/1/Documents/Pubs/950- 153_PerinatalIndicatorsforWashingtonResidents.pdf, May 2012.