[PHYSIO] Pregnancy & Lactation

_ motion at the fimbriated end of the fallopian tube will create a slow current toward the tube opening (ostium)

Ciliary

The sperm cell penetrates the egg through which reactions?

acrosomal reactions

Where does fertilization mainly occur

ampulla of the uterine tube

when does the ovum complete its 2nd meiotic division?

after sperm penetration

at what phase is the ovum suspended during ovulation?

metaphase II

what type of reactions occur to prevent polyspermy

cortical reactions

after sperm entry, where do cortical granules empty their contents?

in perivitelline space

what are the 2 substances that aid in sperm transport

prostaglandins and oxytocin

prostaglandin comes from___

semen

when is oxytocin released?

during orgasm

The early embryo gets early nutrition from ____ secretions adequately prepared for by ___ during the second-half of the uterine cycle

fallopian tube; progesterone

this refers to the vaginal bleeding that may be observed when the blastocyst implants and the trophoblastic cells invade the endometrium

implantation bleeding

one of the most aggressive, highly invasive cells of the human body

trophoblastic tumors

this refers to cancers or malignancies arising from trophoblasts

choriocarcinoma

Metastasis from choriocarcinoma

cannonball lesions

Pregnancy wherein implantation occurred outside of the uterine cavity

Ectopic pregnancy

(T/F) In ectopic pregnancies, 2% of the ovum can be implanted outside of the uterine cavity and fallopian tube.

TRUE. 98% of the ovum is captured by the fallopian tube.

Where does implantation mostly occur in ectopic pregnancies?

Fallopian tube

(T/F) Ectopic pregnancies are not considered as obstetric emergencies

FALSE

What pregnancy hormone is secreted by syncytiotrophopblast cells and is responsible for maintaining the corpus luteum until the placenta is formed?

Human Chorionic Gonadotropin (hCG)

(T/F) The placenta cannot secrete progesterone at all.

FALSE

(T/F) In males, hCG has leutenizing hormone-like effects which stimulate testosterone production in the testis.

TRUE

What is the pregnancy hormone that prevents mentruation from happening?

Human Chorionic Gonadotropin (hCG)

Pregnancy testes rely on hCG found in the ___.

Urine

How early can pregnancy testes detect hCG in urine?

8-9 days post-ovulation or 2-3 days after implantation (for highly sensitive kits)

Until when is the secretion of hCG mantained?

Placental establishment

Name one source of progesterone in pregnant women.

Corpus luteum, syncytiotrophoblasts, placenta

(T/F) Progesterone stimulates uterine contrations.

FALSE. Progesterone prevents uterine contractions.

One role of this hormone is to increase fallopian tube secretions for nourishment of the fertilized ovum/egg.

Progesterone

(T/F) Progesterone causes decidual cells to develop in the endometrium which also nourishes early embryo.

TRUE

Identify the sources of estrogen (2)

Syncytiotrophopblast; Placenta

Effect of estrogen on breasts:

Breast enlargement and development of breast ductal structures

Effect of estrogen on pelvic ligaments:

Relaxation in order to facilitate the enlargement of uterus

(T/F) Estrogen causes contraction of uterus

FALSE. Estrogen causes enlargement of uterus

(T/F) Estrogen causes the enlargement of external genitalia

TRUE

The placenta is organized into villi which contains 2 umbilical arteries and 1 umbilical vein. Which of these carry oxygenated vs deoxygenated blood?

Umbilical arteries carry deoxygenated blood towards the placenta while umbilical veins carry oxygenated blood from placenta towards the fetus.

Normal pO2 levels are around 80-100 mmHg. What are the values for maternal and fetal pO2?

Their values are lower.

Maternal pO2: 50 mmHg

Fetal pO2: 30 mmHg

Fetus adapts to low O2 environment via (α, β, γ, δ?) hemoglobin chains that shift oxyhemoglobin curve to the left (higher O2 affinity)

gamma (γ)

Oligohydramnios: (high/low) amniotic fluid; (renal agenesis/esophageal atresia)?

Oligohydramnios: low amniotic fluid; renal agenesis

Polyhydramnios: (high/low) amniotic fluid; (renal agenesis/esophageal atresia)?

Polyhydramnios: high amniotic fluid; esophageal atresia

T/F. Increased progesterone relative to estrogen is one of the hormonal changes that trigger the delivery of fetus.

False. Estrogen should be higher than progesterone.

List the 3 fetal factors that trigger the delivery of fetus.

Fetal pituitary oxytocin, fetal adrenal cortisol, and prostaglandins release.

Why do multiple pregnancies (twins/triplets) have higher tendency of premature deliveries?

Multiple pregnancies have a higher degree of uterine stretch.

What are the mechanical factors that trigger the delivery of fetus?

1. uterine muscle stretch

2. irritation and stretching of cervix

causes reflex oxytocin secretion

Nipple stimulation

are reflex contractions from labor pains

Abdominal muscle contraction

T/F: Uterine hypoxia during contractions is a type of pain experienced by the parturient and it involves the [somatic nerves].

FALSE: Uterine hypoxia involves visceral nerves

T/F: Cervical and vaginal dilatation during labor is a pain controlled by [visceral nerves]?

FALSE: Cervical and vaginal dilatation involves somatic nerves

When does the uterus return to normal size after delivery?

Around 4 weeks postpartum.

What is Lochia?

The sloughing off of the endometrial surface after delivery, resulting in vaginal discharge.

What are the types of Lochia, their colors, and durations?

Lochia Rubra: Red, 3–5 days

Lochia Serosa: Serous yellowish, 5–10 days

Lochia Alba: Whitish, 10 days to weeks

What is Placenta Previa?

Condition where placenta blocks the cervix

How does placenta previa present?

Presents as vaginal bleeding

How is Placenta Previa detected ?

Detected by ultrasound

How should a baby be delivered in the case of placenta previa?

Requires cesarean delivery (obstetric emergency)

What is Abruptio Placenta?

Premature detachment of the placenta

Presentation of abruptio placenta

Presents as vaginal bleeding

Medical risk of abruptio placenta

Risk of baby dying from exsanguination (loss of blood)

How should a baby be delivered in the case of abruptio placenta?

Requires cesarean delivery (obstetric emergency)

What placental abnormality occurs in parturition?

Abnormal depth and attachment of the placenta

Cause of abnormal depth and attachment of placenta

Caused by aggressive trophoblast development

What happens to the size of uterus, vagina, and breast during pregnancy?

Increases

What is the typical overall weight gain during pregnancy?

Around 25-30 pounds

During pregnancy, there is an increase in which hormones that boost metabolism?

Thyroxine, cortisol, and sex hormones

What is the name of the pigmented area around the nipples that enlarges and darkens during pregnancy?

Areola

What is the dark vertical line that appears on the midline of the abdomen called in hyperpigmentation during pregnancy?

Linea nigra

What is melasma commonly referred to during pregnancy?

Mask of pregnancy

Which body areas commonly darken (hyperpigmentation) during pregnancy aside from the areola and abdomen?

Armpits and skin crevices

Pregnant women need higher amounts of which five nutrients?

Iron, calcium, vitamin D, vitamin K, and protein (plus total calories)

Morning sickness during pregnancy is associated with increased levels of which three hormones?

hCG, estrogen, and progesterone

By how much does the blood volume increase during pregnancy?

Around 30%

When does the peak of cardiovascular load happen during pregnancy?

At 28 weeks AOG (age of gestation)

Pregnant women are advised to supplement with which vitamin to prevent neural tube defects?

Folic acid

Folic acid supplementation can help prevent which two birth defects?

Neural tube defects and cleft lip and palate

During lactation, the lobules are prepared by?

Progesterone

This hormone prepares the ductal system while also influencing fat deposition

Estrogen

T/F: Estrogen and Progesterone inhibits milk secretion

TRUE

T/F: Prolactin inhibits milk secretion

False — prolactin promotes milk secretion and inhibits GnRH secretion explaining the infertility if the mother continues breastfeed after delivery

This hormone offers temporary infertility

Prolactin

This hormone has lactogenic effect

Somatomammotropin

T/F: High levels of estrogen and progesterone inhibit lactation

TRUE — these hormones prepare the ductal and lobular system of the breast

How do estrogen and progesterone levels change after delivery?

Drop in estrogen and progesterone levels → loss of “milk inhibitor” hormones → prolactin effects predominate → lactation

Besides prolactin, which hormones affect the constitution of milk during production?

Growth hormone, insulin, cortisol, and parathyroid hormone

This hormone checks and balances the effects of prolactin by controlling its release

Prolactin Inhibitory Hormone (PIH)

T/F: Prolactin Inhibitory Hormone (PIH) is secreted by the anterior pituitary

False — it is secreted by the hypothalamus

"hormone responsible for the ""milk let-down"" reflex"

Oxytocin

Where is oxytocin released from during breastfeeding?

The posterior pituitary gland

Which cells does oxytocin cause to contract during milk ejection?

Myoepithelial cells

How much breast milk does a mother typically produce per day?

About 1.5 liters

What is colostrum, and why is it important?

It’s the first few milliliters of breast milk rich in anti-infective agents that protect the baby’s gut

Which immune components are found in breastmilk?

IgA antibodies, neutrophils, and macrophages

What hormone inhibits GnRH to prevent immediate pregnancy during breastfeeding?

Prolactin

T/F: Breastfeeding can help mothers lose weight faster after pregnancy

TRUE

Besides physical benefits, what emotional benefit does breastfeeding offer mothers?

Increased bonding with the child

How does breastfeeding help the uterus after delivery?

It keeps the uterus contracted and helps prevent further bleeding

Which hormone causes uterine contraction during breastfeeding?

Oxytocin

What causes the initial stretching of the cervix at the end of pregnancy?

The weight and pressure of the fetal head

What hormone is released from the pituitary gland due to cervical stretching?

Oxytocin

How does cervical stretching enhances uterine contractions during labor?

It causes a local reflex for uterine contractions and stimulates oxytocin release, leading to stronger contractions.

What is the result of the positive feedback mechanism during labor?

A. Relaxation of uterus

B. Delivery of the baby and placenta

C. Formation of the placenta

D. Initiation of lactation

B. Delivery of the baby and placenta