Chapter 18 - Obstetrics - Stages & Phases Of Labor, Drugs.

Front 1

Pregnancy: 4 stages

Back 1

1) Prenatal - between conception and onset of labor, refers to both care of mother and growth and development of fetus. 2) Labor - last phase of pregnancy to time of delivery. 3) Parturition/childbirth/delivery - act of giving birth. 4) Postpartum/Puerperium - 6 weeks following childbirth and expulsion of placenta. Female reproductive organs usually return to an essentially prepregnant condition in which involution of uterus (return of uterus to normal size after childbirth) occurs.

Front 2

Signs of Pregnancy - 3 types

Back 2

Subjective - those experienced by expectant mother. 2) Objective: those observable by examiner. Can be caused by other conditions and not considered to be positive signs of pregnancy. 3) Diagnostic/Positive signs - only absolute indicators of a developing fetus: a) Fetal heartbeat can be detected by ultrasound at approx 10 weeks gestation or by using a fetoscope - optical device used for direct visualization of fetus in uterus at approx 18-20 weeks of pregnancy. b) Fetal movements can be felt by examiner in 2nd trimester by ultrasonography, high-frequency sound waves that visualize a structure or produce a record of ultrasonic echoes as they strike tissues of different densities. c) Visualization of fetus using ultrasound as early as 4-5 weeks of gestation with 100% reliability providing earliest positive confirmation of pregnancy.

Front 3

True Labor

Back 3

True labor characterized by rhythmic contractions that develop a regular patterns and are more frequent, more intense and last longer. General feeling of discomfort felt in lower back and lower abdomen. Bloody show often present and progressive effacement & dilation of cervix..

Front 4

Stages of Labor - 3

Back 4

1st stage: Dilation stage. Begins with onset of true labor and lasts until cervix is fully dilated to 10 cm. 2nd stage=Expulsion. Continues from cervix at 10 cm till delivery of baby. 3rd stage = delivery of placenta.

Front 5

First stage of labor = 3 phases.

Back 5

Early labor/latent phase: Begins with onset of labor till cervix dilated to 3 cm. Duration=8-10 hours. Contractions=30-45 secs. Rest between contractions: 5-30 mins. Contractions are typically mild, somewhat irregular, but become stronger and closer together. Bag of waters can break any time during 1st phase. 2nd phase/Active Labor phase. Till cervix dilated to 7 cm. Duration about 3-5 hours. Contractions last 45-60 secs. Rest between contractions= 3-5 mins. Effacement of cervix is completed. 3rd/Transition phase: till cervix fully dilated to 10 cm Duration = 30 mins - 2 hours. Contractions=60-90 secs. Rest periods = 30secs- 2 mins. Contractions long, strong, intense and may overlap.

Front 6

Second stage of labor

Back 6

Lasts from time of full cervical dilation (10 cm) till birth of baby. Process time- 20 mins -2 hours or longer. Contractions=45-90 secs. Rest period =3-5 mins. Strong natural urge to push with feeling of pressure on rectum.

Front 7

Third stage

Back 7

Delivery of placenta. Time taken 5 -30 mins. Examined to be certain that all of it has been expelled otherwise any small portion of placenta could interfere with uterine contractions after baby birth and contribute to infection.

Front 8

Crowning

Back 8

Head of baby appears first. Head is cone-shaped or molded due to journey down.

Front 9

Vernix caseosa

Back 9

Protective cheesy substance that covers fetus during intrauterine life.

Front 10

Lanugo

Back 10

Fine downy hair covering newborn - especially shoulders, back, forehead, and temple.

Front 11

Apgar score

Back 11

Taken 1 and 5 mins after birth. High score=10, low score=1.

Front 12

Epidural Block

Back 12

To reduce discomfort and pain of contractions. Small amount of anesthesia inserted through a narrow catheter that is threaded through a needle inserted into dura space near spinal cord.

Front 13

Pudendal block/Local anesthetics

Back 13

Used to numb vaginal area in preparation for an episiotomy. Provides regional pain relief in perineum area during birth.

Front 14

Oxytocic agents/uterine stimulants.

Back 14

Drugs that selectively stimulate contraction of myometrium - muscular middle layer of uterus. Used in obstetrics to induce labor at term and to control postpartum hemorrhage.

Front 15

Perineum

Back 15

Region bounded by inferior edges of pelvis. In female, located between vulva and anus. Is a muscular sheet that forms pelvic floor and during childbirth can be torn and cause injury to anal sphincter. To avoid such injury, episiotomy - surgical procedure to prevent tearing of perineum and facilitate delivery of infant is usually performed.

Front 16

Colostrum

Back 16

First milk - thin yellowish secretion containing mainly serum and white blood cells

Front 17

Oxytocin

Back 17

Hormone released by posterior lobe of pituitary gland. Baby's suckling releases oxytocin in mother which stimulates uterine contractions and promotes return of uterus to normal nonpregnant size and state. Also acts on mammary glands to stimulate release of milk.