THERIO - Pregnancy & Parturition Disorders, Dystocia, Planned C-section Flashcards by Jessica Hanaumi

Parturition occurs approximately:
___ days after LH surge
___ days after ovulation
___ days after onset of cytological diestrus (vaginal cytology)

Parturition occurs approximately:
65 days after LH surge
63 days after ovulation
57 days after onset of cytological diestrus (vaginal cytology)

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Can palpate abdomen and feel individual puppies ____ days post LH surge, but should only do once or can cause damage.

21-35 days post LH surge

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Pregnancy Diagnosis: Ultrasonography

Dogs and cats

Pregnancy DX: ultrasonography

Dogs & Cats: as early as 17 days, but usually 30 days post LH surge

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Pregnancy DX: Radiographs

Dogs vs Cats

Pregnancy DX: Radiographs

Dogs: 42-45 days post LH surge
Cats: 38-40

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Pregnancy DX: Relaxin

Dogs & Cats

Pregnancy DX: Relaxin

Dogs: from 25 days post LH surge (peaks at 40 days)
Cats: from 25 days post breeding

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Pregnancy Diagnosis: Prolactin

Dogs vs. Cats

Pregnancy DX: Prolactin

Dogs from 35 days post LH surge
Cats from 20 days

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How is ultrasonography used for gestational aging?

Measure inner chorionic diameter - look at chart

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When is the heartbeat visualized on ultrasound?

When is fetal movement visualized on ultrasound?

Heartbeat 23-25 days post LH surge
Fetal movement 34-36 days post LH surge

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Fetal skeletal calcification of the spine and skull begins _____ days post LH surge.

Fetal teeth radiopaque at ____ days post LH surge.

Evaluate size and number at ___ days post LH surge for planning/dystocia.

Fetal skeletal calcification of the spine and skull begins 42-46 days post LH surge.

Fetal teeth radiopaque at 58-63 days post LH surge.

Evaluate size and number at 55 days post LH surge for planning/dystocia.

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This hormone is produced primarily by the canine placenta, and serum levels rise significantly beginning 20-30 days post LH surge.

What if the test is negative in early gestation?

Relaxin

Negative results in early gestation should be rechecked by testing 7-10 days later.

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Why isn’t progesterone reliable for pregnancy diagnosis?

What levels of progesterone indicate an at risk pregnancy?

What levels of progesterone indicate imminent delivery or abortion?

Levels are the same whether pregnant or not.

<6 at risk
<2 about to deliver or abort

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Visualizing fetal resorption on ultrasound, ___ is first to disappear - may see ____ for longer time.

DFDX for fetal resorption and how to differentiate

Visualizing fetal resorption on ultrasound, fluid is first to disappear - may see fetus for longer time.

DFDX: pyometra, cystic endometrial hyperplasia
Differentiate with bloodwork

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Normal fetal heart rate:

Stressed fetal heart rate:

When do you expect a normal decrease in fetal heart rate?

What fetal heart rate indicates they cannot be saved medically and require c-section?

Normal fetal HR: >190 bpm (2-3X mother)
Stressed fetal HR: <190 bpm
HR decreases ~20 days from parturition
HR around 180 at due date is normal
HR <160 need c-section; cannot save medically

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Fetal anasarca is a common genetic abnormality with ___ breeds.

Brachycephalic

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Four measurements that can be used for gestational aging using ultrasonography

ICC - Inner chorionic cavity
CRL - Crown rump length
BPD - Biparietal diameter: visualize both ventricles or ears; most accurate in large breed dogs
BD - Body diameter

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Gestational aging using radiographs is ____.

Inaccurate

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The embryo should be present in the gestational sac at ___ days post LH surge.

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Kidneys on ultrasound to determine if puppies are mature enough for c-section

Another indication of maturity:

If can differentiate cortex and medulla

Intestinal layers visible + peristalsis

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More than 70% of fetal growth occurs ____.

Weight gain before 40 days should not be more than ___.

During ____ the fetuses grow rapidly with a body weight increase of 15-25%.

In queens, weight gain occurs ____.

After the first 5 weeks of pregnancy
25-30% of the pre-breeding weight
Last 3-4 weeks
Queens - linear weight gain

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Nutrition: Switch to a commercial brand ____ at breeding or pregnancy diagnosis.

Puppy food
NOT large breed puppy food or raw

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Consequences of inadequate nutrition in addition to poor milk quality and puppy growth.

Ketosis:
Eclampsia:
Cleft palate:
Gestational diabetes mellitus:

Ketosis: inadequate nutrition/not enough carbohydrates to meet energy demands

Eclampsia: toy/small breeds due to calcium supplementation during gestation; ataxia, muscle tetany, convulsive seizures

Cleft palate: folic acid deficiency

Gestational diabetes mellitus: due to inadequate endogenous insulin supply

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How long does lactation last?

German shepherds can produce up to ___ kg of milk/day at peak lactation.

7-8 weeks in dogs and cats

1.7

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Bitches and queens consume __ times their maintenance energy requirements during lactation

1st week _____X
2nd week _____X
3rd & 4th weeks _____X

1st week 1-1.5X
2nd week 2X
3rd & 4th weeks 2.5-3X

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Factors influencing transfer of drugs across the placenta (10)

Placental blood supply
Age of gestation
Placental drug-metabolizing capabilities
Drug size
Drug lipid solubility
Drug dose
Duration of drug exposure
Maternal/fetal pH differential
Maternal/fetal drug protein-binding differences
Species of animal

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Drug categories ABCD

A - probably safe B - safe if used cautiously C - may have potential risks D - contraindicated

Parturition is initiated by: Fetal adrenal glands produce ___ which induces production of _____ by fetal placentas.

Fetuses respond to uterine crowding Fetal adrenal glands produce cortisol Cortisol induces production of PGF2a by fetal placentas

Affect of litter size on gestation: Gestation of older bitches, greyhounds, CKCS:

Small litters may have prolonged gestation, large litters may have shorter gestation Older bitches and greyhounds - longer gestation CKCS - shorter gestation

When does cortisol level peak? 12-24 hours later ____ increases (restless behavior and prodromal signs) 24-36 hours later ____ declines ____ is produced by fetal placentas to relax pelvic ligaments and vaginal tissue

24 hours prior to parturition Prolactin Progesterone Relaxin

In late gestation, pregnancy is maintained by _____ > 5 ng/mL. When it drops below ___ ng/mL parturition begins within 8-24 hours.

Progesterone 2

Progesterone is _____. _____ results in transient decrease in body temperature < 99F so monitor rectal temp at least twice/day.

Thermogenic Luteolysis

End of gestation progesterone decline is concurrent with increased ___ levels.

Prolactin

What does a tocodynamometer measure? How is it useful?

Pressures associated with contraction of the uterus Helpful to identify beginning of labor and progression (either normal or abnormal)

Stage 1 of Labor Increasing ___ and ___ stimulate myometrial contractions. Neural stimulus caused by cervical pressure results in hypothalamic stimulation of _____ release from the pituitary, further stimulating myometrial contractions. May see these five behaviors: Duration:

Stage 1 of Labor Estradiol, prostaglandin Oxytocin Panting, nervous, restless, nesting, vomiting 4-12 hours

Stage 2 of Labor Marked productive _____. Visible abdominal ____. ____ expelled. ____ may be visible. First puppy delivered within ____ hours. Litter fully delivered within ____ hours. Once fetus is visible at caudal pelvic canal, it should be delivered within ____. ____% of dystocias occur before delivery of the first puppy.

Peristaltic contractions of the uterus Straining Green or clear fetal fluids Amniotic sac 4 12 20 minutes 61.1%

During the second stage of labor mild, occasional ____ is normal. Puppies are born from ____ with the first from the side with more puppies. Bitches can experience transient ____ to allow for the dispersal of lactic acid accumulated in the myometrium. During this time, the bitch can be brought out.

Vomiting Alternate uterine horns Whelping pause

Abnormal Stage 2 Large amount of _____. Check yard for puppy if _____. Labor should not be allowed to continue beyond _____. Abnormalities most commonly occur during stage 2 as a result of _____.

Bright red/dark red/brown fluid If bitch went outside unsupervised 24 hours Dystocia

What occurs during stage 3 of labor? Why might stage 2 and 3 overlap?

Passing of placenta, shortening of uterus, rest period of 1-2 hrs Because some fetal membranes are passed with individual puppies

What are SIPS?

Sub-involution placental sites

Uterine Involution 1st week PP: uterine horns ____ and placental sites prominent and covered with _____. By 9 weeks PP: uterine horns _____. ___ not observed at the placental sites. Regeneration and replacement of the ____ is not complete. Uterine involution complete ____ weeks PP. Normal lochia may be present for ___ weeks PP.

Dilated and edematous Mucous/blood clots Uniform in shape and contracted with a narrow lumen Trophoblast-like cells Endometrial lining 12-16 weeks PP 6-8 weeks PP

Four predisposing causes of dystocia

Very small litter size (1-2 puppies) Old bitches (>3 years old) Primiparous older than 6 years Increased incidence in Boxers >4 years old

Dystocias - Reasons for veterinary evaluation: Prolonged gestation > ___ days from ovulation or >____ days from first breeding No signs of labor 24-36 hours after _____ More than ___ hours between rupture of fetal membranes and delivery of first puppy. Active uterine contractions _____ without expulsion of fetus.

>65 days from ovulation or >72 days from first breeding Temp drop (start testing 1 week before due date) 4 hours More than 30 minutes

Dystocias - Reasons for veterinary evaluation More than ___ hours between births. No fetus produced ____ hours after onset of labor. ____ vaginal discharge. Bitch has delivered ____ or been in second stage labor for more than ____.

2 hours 4 hours Abnormal Stillborn, 12 hours

Maternal factors account for ___% of dystocias and include:

75% Uterine inertia Small birth canal Uterine torsion Hydrops Extreme nervousness Inguinal hernia

What is uterine inertia and what are some causes?

Inability of the uterus to contract Sepsis, illness, age-related, genetic inability of myometrium to contract, primary inertia when there are only few fetuses

Treatment for complete or partial primary inertia and secondary inertia

C-section

C-section is indicated if more than ___ fetuses remain with primary/secondary inertia.

Surgery needed if more than four fetuses remain.

What condition is this? Normal birth canal Some fetuses born Uterus becomes fatigued

Partial primary inertia

What condition is this? Uterus is exhausted due to obstruction to passage of fetus due to narrow pelvic canal, large fetus, abnormal presentation, fetal malformation, vaginal septum, or extensive vaginal stricture.

Secondary inertia

What condition is this? Normal birth canal No fetuses delivered Uterine dysfunction due to small litter/inadequate stimulation, large litter and over-distended uterus, systemic disease, electrolyte imbalance, fatty infiltration of uterus, uterine age, or unknown cause.

Complete primary inertia

Fetal factors account for ____ % of dystocias in dogs and ___% in cats and include:

Dogs - 25% Malpresentation, malformation, fetal oversize, fetal death Cats - 30% Malpresentation, malformation, fetal oversize

Dystocia Signalment _____ bitches less than two years old _____ breeds _____ litters Not as common in ____.

Primiparous bitches less than two years old Toy and small brachycephalic breeds Very large or very small litters (superfecundation) Not as common in cats

Dystocia Clinical Signs

Vocalization Biting/chewing at vulvar region Abnormal vulvar discharge Fetus protruding from vulva Systemic illness - fever, weakness, tremors

Dystocia Diagnostics Physical exam Progesterone evaluation Vaginal Exam - what should you check?

Check for fluids and relaxation of vagina Check for presence of fetus in/at pelvic inlet Assist normal delivery by gentle traction on head/pelvis

Dystocia - abdominal radiographs can be used to assess:

Size, number, position, location of fetuses +/- fetal viability Maternal pelvic structure and status of the abdomen

Dystocia - Transabdominal ultrasonography can be used to assess:

Fetal viability, fetal malformations 180 bpm big breeds still OK 180 bpm small breeds = fetal distress <150 bpm C-section

Fetus in the birth canal Attempt _____. Can use sterile _____ +/- sterile ______. Dam standing or laterally recumbent + _____. Posterior-ventral traction of fetus. ____ should be avoided. ____ can be performed at the dorsal vulvar midline if vulvar opening is too narrow. If unable to remove fetus: ___!

Attempt manual removal. Sterile lube (diluted), sterile red rubber catheter Dam standing or laterally recumbent + caudal abdominal palpation Posterior-ventral traction of the fetus Obstetrical instruments should be avoided Episiotomy C-Section

Dystocia - Medical Management Drug: Dose as a _______ agent 11mg/kg diluted in saline administered IV over 10-15 minutes while monitoring EKG. If noted hypocalcemia, administer 50-150 mg/kg over 10-15 minutes while monitoring EKG.

Calcium Gluconate 10% Uterotonic

Medical management - Dystocia Monitor ____ when using calcium gluconate

EKG

Dystocia - Medical Management What should be treated prior to using oxytocin? Three considerations prior to using oxytocin? Uterine rupture = ________. Dosage Dogs: 0.5-2 units IM/IV Cats: 0.5 units IM/IV If no fetus can repeat dosing _____ +/- 0.5% mg/kg 10% _____ slowly IV. ______ additional doses of oxytocin recommended past this point.

Hypoglycemia, hypocalcemia Obstruction of birth canal, oversized fetus, abnormal presentation of fetus Uterine rupture = fetal death 30 minutes later +/- 10% Dextrose slowly IV NO additional doses

Dystocia - Medical Management Prognosis: % success: Dystocia lasting more than 6 hours =

Prognosis guarded 20-40% success with medical management Dystocia lasting more than 6 hours = increased stillbirth rates

Emergency C-Section Prophylactic abx only if _____. C-section +/- _____. Depending on dam and fetal status, staff available, and surgeon’s choice.

Only if there was a manipulation or other indications +/- OHE

Emergency C-Section: Anesthesia Placement of IV catheter. Pre-med: Induction: Tracheal tube placement. Epidural: Maintenance: Intra-op as needed: Post-op: Incision: IV fluids: +/- Oxytocin and _____, _____, or _____

Emergency C-Section: Anesthesia IV catheter placement Pre-med: Fentanyl Induction: Propofol TT placement Epidural: morphine and lidocaine Maintenance: sevoflurane Intra-op as needed: fentanyl Post-op: methadone or other opioids Incision: bupivicaine IV fluids: LRS +/- Oxytocin and dopamine, dobutamine, or norepinephrine

Reasons for elective C-sections: ____ disproportion (brachycephalic breeds) ____ whelping history Previous _____ Inherent _____ High risk _____ ____ puppies/bitches ____ semen pregnancy Owner ____

Fetopelvic disproportion Poor whelping history Previous C-section Inherent uterine diseases High risk pregnancy Highly valuable puppies/bitches Frozen semen pregnancy Owner convenience

Elective C-Section Ovulation timing: (3) Ultrasound Radiographs First stage of labor

LH surge Ovulation day Vaginal cytology (first day of diestrus)

Elective C-Section Indicated Medications Corticosteroid therapy: short-acting (____) 2-12 hours before; starting at 57 days to stimulate ____. ______: 5-10 mcg/kg to induce luteolysis and increase prolactin. Intranasal ____ to accept the puppies 10 IU every 2h or before each feeding to nulliparous bitches Sedatives like ___ as anxiolytic; acepromazine use is debated.

Betamethasone, surfactant PGF2a Intranasal oxytocin Diazepam