1. Pregnancy and Lactation.
Prof. K. Sivapalan.

2. Uterus is There to Develop Fetus.
11/19/2018
Pregnancy and Lactation

3. Changes in Primary Oozyte.
The ovum is in primary oocyte stage in ovary.
Miosis is completed just before ovulation and first polar body is expelled
It has 23 unpaired chromosomes and is named secondary oocyte.
The secondary oocyte with corona radiata is expelled in to the peritoneal cavity.
The cilia in the fimbriated tentacles of the fallopian tube beat towards the uterus.
This moves the fluid into the tube and the fluid carries the ovum with it.
11/19/2018
Pregnancy and Lactation

4. Movement of Sperms and Ovum
The ovum disintegrates in 3 days if not fertilized.
The ovum is fertile for only one or two days after ovulation.
Sperms deposited by ejaculation in the vagina start moving and a few thousand reach both ampullae of the fallopian tubes.
?sperms express olfactory receptors and ovaries produce odorent-like molecules which exert chaemotactic effect.
The ovum usually meets the sperm in the ampula and fertilization occurs there if insemination and ovulation occurred at or around the same day.
11/19/2018
Pregnancy and Lactation

5. Penitration of Zona Pellisuda.
The sperms that meet the ovum first react with the corona radiata by their acromosomal enzymes.
The sperms that come after words pass through the path created and react with the granulosa cells if present.
The sperm that meets the zona pellucida of the ovum binds with receptors.
The sperm releases its acrosome to make way through the zona pellucida.
Only one sperm fertilizes but several sperms are needed to make the way to ovum.
11/19/2018
Pregnancy and Lactation

6. Pregnancy and Lactation
Fertilization.
When the sperm meets the membrane of the ovum, it binds with the membrane and releases its nuclear material into the cytoplasm of the ovum.
Binding with the membrane reduces the membrane potential.
This prevents polyspermy immediately.
Structural changes in zona pellucida follows to prevent polyspermy on a long term basis.
This is followed by fusion of both nuclei to become diploid once again- fertilization.
11/19/2018
Pregnancy and Lactation

7. Pregnancy and Lactation
Sex Determination.
23 pairs of chromosomes in cells
Male: 44 +“XY”
Sperms Y or 22 + X
Female: 44 + “XX”
Ovum X
Who determines the sex of the baby?
11/19/2018
Pregnancy and Lactation

8. Pregnancy and Lactation
Implantation.
Movement of the cilia of the fallopian tube carries the fertilized ovum into the uterus over the next three to five days.
The last 2 CM of fallopian tubes relax under the influence of the rising progesterone.
The developing embryo burrows into the dorsal endometrium- implantation.
11/19/2018
Pregnancy and Lactation

9. Amenorrhea of Pregnancy.
The chorionic membrane, which later becomes the placenta, secrets Human Chorionic Gonadotropin.
HCG can be detected by radioimmunoassay by the sixth day of fertilization.
HCG supports the corpus luteum to continue secretion of estrogen and progesterone in large amounts.
This prevents breakdown of the endometrium and menstrual flow.
The fetus secures its existance.
11/19/2018
Pregnancy and Lactation

10. Pregnancy and Lactation
Placenta.
The placenta has to provide oxygen and nutrients to and remove wastes from the fetus.
Umbilical vein and artery form villi covered with chorion.
Inter villus space is filled with maternal blood.
Maternal arterioles open into and venules drain the blood from this space. [no capillaries]
This increases cardiac output but reduces peripheral resistance.
Pulse pressure increases.
11/19/2018
Pregnancy and Lactation

11. Functions of the Placenta.
The decidual cells are greatly swollen and nutritious to feed at the blastocyst in early part of the pregnancy.
Diffusion of nutrients from maternal blood into fetal blood as in intestine- facilitated diffusion for glucose.
Diffusion of oxygen- affinity of fetal hemoglobin, hemoglobin content [20g/dl], Bohr effect.
Diffusion of excretory substences from fetus into maternal blood.
Endocrine function- HCG, estrogen, progesteron,Human Chorionic Somato Mamotropin and Relaxin.
11/19/2018
Pregnancy and Lactation

12. Human Chorionic Gonadotropin
It is a glycoprotein like LH and FSH.
It is primarily luteotropic and has some FSH like activity.
Presence in urine is the basis for urine test for pregnancy after 14 days.
Small amounts can be secreted by some tumors of GIT.
It stimulates further development of corpus luteum and secretion of estrogen and progesterone for the first three months.
It stimulates secretion of testosterone by male testes.
11/19/2018
Pregnancy and Lactation

13. Pregnancy and Lactation
Estrogen in Pregnancy.
Enlargement of the mothers uterus.
Increased oxytocin receptors and excitability of myometrium.
Growth of breast ductal structure.
Enlargement of mothers external genitalia.
Relaxation of pelvic ligaments- sacro-iliac joint becomes elastic.
Retention of sodium and water- increased ECF.
Increased deposition of fat.
11/19/2018
Pregnancy and Lactation

14. Progesteron in Pregnancy.
Development of decidual cells- early nutrition of embryo.
Reduce contratility and prevents expulsion.
Development of glandular structure of breast.
11/19/2018
Pregnancy and Lactation

15. Human Chorionic Somatomammotropin.
A protein with MW of 38,000.
Progressively increases after 5th week of pregnancy.
Growth Hormone like action but 100 times less potent.
Anti insulin action- reduced glucose utilization and increased lipolysis in mother.
11/19/2018
Pregnancy and Lactation

16. Change in Endocrine System.
Pituitary: anterior lobe enlarges 50 %. Secretion of ACTH, TSH and prolactin increased.
Adrenal: glucocorticoids moderately increased.
Thyroid: enlarges by 50%. Secretion increased by, TSH and HCG
Parathyroids: increased secretion.
11/19/2018
Pregnancy and Lactation

17. Pregnancy and Lactation
Maternal Weight gain.
About kg-
Uterus kg.
Baby kg.
Amniotic fluid, placenta- 2 kg.
Breasts – kg.
Fluids kg.
Fat kg.
11/19/2018
Pregnancy and Lactation

18. Nutrient Needs in Pregnancy.
Energy for carrying extra weight.
Increased metabolic rate.
Supply for fetus.
Storage of protein and other substances in early months for use in last 2 months.
Fe for maternal and fetal blood 375 and 600 mg respectively.
Vitamins and minerals for increased metabolism and rapidly developing fetus.
11/19/2018
Pregnancy and Lactation

19. Pregnancy and Lactation
Circulatory Changes.
Blood volume- 30 % increase [compensate for loss during normal delivery].
Increased cardiac output.
Reduced Peripheral Resistance- placenta, metabolites in tissues.
11/19/2018
Pregnancy and Lactation

20. Pregnancy and Lactation
Other changes.
Respiration- increased oxygen need and carbon dioxide production but growing uterus reduces excursion of the diaphragm.
The respiratory rate increases.
In kidney, GFR increased, absorptive capacity of tubules also increased.
11/19/2018
Pregnancy and Lactation

21. Pregnancy and Lactation
Mental Changes.
Nausea and emotional disturbance in first trimester.
Feeling of emotional well being in second and third trimesters.
States of emotional distress and miner depression is relatively common especially when pregnancy is unwelcome or associated with social adversity.
First pregnancy and anxious personalities may have high level of anxiety needing reassurance and information.
11/19/2018
Pregnancy and Lactation

22. Pregnancy and Lactation
Onset of Labour.
Duration of pregnancy- 270 days from fertilization [294 days from LRMP].
At term, estrogen-progesteron ratio increases. It is one cause of increase in contractions.
Oxytocin increases the force of contraction leading to delivery of the baby.
Fetal oxytocin, cortizol, prostaglandins released by fetal membranes may be responsible for the onset of labor.
Stretch of the growing fetus on the uterus may be another factor.
Stretch or irritation of the cervix is another factor.
The positive feed back – baby's head stretch cervix- contraction – more stretch.
11/19/2018
Pregnancy and Lactation

23. Pregnancy and Lactation
Parturition.
Pain during contraction of the uterus is due to hypoxia, transmitted through autonomic afferents.
As the baby descends through the birth canal, stretch of the cervix and genitalia causes more pain transmitted through somatic nerves.
Tears of the genitalia may cause severe pain.
Separation of placenta opens sinusoids and about 350 ml blood will be lost.
This is followed by blood stained discharge ‘lochia’ which turns into serous in nature and stops by about 10 days.
11/19/2018
Pregnancy and Lactation

24. Pregnancy and Lactation
Puparium.
6 weeks after partus.
Uterine involution- about 4-5 weeks. Oxytocin and prolactin released by lactation seems to facilitate.
Amino acids released by involution diffuse into the blood.
Lochia- uterine discharge with blood and necrotic decidua- about 10 days.
Blood and ECF volume and cardiac output return to pre pregnancy value soon.
11/19/2018
Pregnancy and Lactation

25. Pregnancy and Lactation
Colostrum
It is the yelloish secretion from mammory glands during the last few days of pregnancy and the first few days after partus.
Mainly on the first day.
It contains protein and lactose but no fat.
Proteins are largely IgA, absorbed by baby without digestion.
These are important for protection from infections.
Importance of giving tetanus toxoid to the mother to prevent neonatal tetanus.
11/19/2018
Pregnancy and Lactation

26. Pregnancy and Lactation
High levels of hormones during pregnancy prepare the breast for lactation.
Breast secrets milk increasingly over the first 7 days under prolactin.
Secretion of milk reduces in 7 to 9 months but if baby sucks, continuous secretion.
Prolactin also inhibits gonadotropin secretion and amenorrhea continues.
Oxitocin is needed to eject milk from alveoli into ducts.
Hearing baby crying or fondling the baby can stimulate oxitocin secretion. But psychological factors inhibit.
Feeding alternatively from both breasts as ejection is for both breasts.
11/19/2018
Pregnancy and Lactation

27. Pregnancy and Lactation
11/19/2018
Pregnancy and Lactation

28. Pregnancy and Lactation
11/19/2018
Pregnancy and Lactation

29. Pregnancy and Lactation
11/19/2018
Pregnancy and Lactation

30. Pregnancy and Lactation
11/19/2018
Pregnancy and Lactation

31. Pregnancy and Lactation
11/19/2018
Pregnancy and Lactation

32. Breast Feeding: Pleasant for Mother, Development for Daby.
11/19/2018
Pregnancy and Lactation

33. Importance of Breast Feeding.
Bonding between mother and baby.
Mental development for baby.
Feed in right temperature, right taste and composition.
Protection by antibodies.
Immunoglobins of cow or other animals are digested.
Clean and readily available.
11/19/2018
Pregnancy and Lactation

34. Reproductive Function---
When does it start?
When does it end?
Who are the participants?
Who is responsible?
11/19/2018
Pregnancy and Lactation