Obstetrics 1st lecture Flashcards
1
Q
“The branch of medicine that concerns the management of pregnancy, childbirth and the puerperium.”
A
Obstetrics
2
Q
“The study of… diseases & conditions that affect reproduction and the female reproductive system.”
A
Gynecology
3
Q
Gravida
A
Pregnant
4
Q
Gravidity
A
of pregnancies
5
Q
Primigravida
A
first pregnancy
6
Q
Nulligravida
A
never pregnant
7
Q
parous
A
bearing offspring of a specified number or reproducing in a specified manner.
8
Q
Parity
A
number of births a woman has had
9
Q
nulliparous (“nullip”)
A
not given birth yet
10
Q
Primipara (“primip”)
A
person who has had one birth. In OB is a woman, who is about to give birth a second time.
11
Q
Multipara (“multip”)
A
given birth several times
12
Q
two main systems to indicate pregnancies & births
A
GPA
TPAL
13
Q
GPA
A
Gravidity, parity, abortions
G2 P1 A1
14
Q
TPAL
A
gravidity & 4 classifications of outcome >Term deliveries >Preterm deliveries >Abortions >Living children (live births)
15
Q
Term pregnancy (in weeks)
A
37-41 weeks
16
Q
Preterm (dates)
A
before 37 weeks
17
Q
Abortion
A
end of pregnancy before viability
18
Q
point of viability
A
22 weeks
19
Q
Perinatal death (mortality) rate
A
of stillbirths and neonatal deaths per 1000 births
National goal < or equal to 10/1000
Neonatal death considered within 28 days after birth
20
Q
Maternal Mortality
A
Death of a pregnant woman during pregnancy or within 6 weeks of delivery or termination
21
Q
Maternal Mortality rates
A
Expected rate: <20/100,000 births
11-12/100,000 in the USA
50 – 200/100,000 in developing nations
Historical rates: 1-3% (1,000 – 3,000/100,000)
22
Q
obstetrical dates
A
Weeks of pregnancy completed since the LMP (first day of the last menstrual period)
23
Q
Menstrual cycle variation
A
Mean = every 28-29 days
Normal range = 24 – 35 days
24
Q
Average length of human pregnancy
A
266 days after conception (fertilization) 40 weeks (280 days) after the LMP
25
EDD
Estimated Date of Delivery (EDD)
| 90% of pregnancies end at EDD + 3 wks
26
First Trimester
First: conception thru 13 weeks
27
Second Trimester
Second: 14 – 27 weeks
28
Third Trimester
Third: 28 – 40 weeks
29
First Timester Highlights
Fetal stage of development begins at 10 weeks
| Most pregnancy losses occur here
30
Second Timester Highlights
Time of rapid and major physiological adjustments
| Fetal viability begins at approximately 22 weeks
31
Third Timester Highlights
Labor becomes increasingly likely
| Fetal viability increases rapidly
32
HCG
Human Chorionic Gonadotropin
33
Uterine Growth Landmark
Non-Pregnant
Non-pregnant: “size of your fist”
| Nulliparous: slightly smaller
34
Uterine Growth Landmark
12 weeks
12 weeks: palpable just at or slightly above pubic symphysis
35
Uterine Growth Landmark
20 weeks
20 weeks: palpable at the umbilicus
36
Uterine Growth Landmark
36 weeks
36 weeks: palpable at the xiphoid
37
Ultrasound landmarks
Gestational sack at 5-5.5 weeks
2 mm embryo at 5.5-6 weeks
Cardiac activity at 5.5-6 weeks
38
Ultrasound:
Diagnostic ultrasound is safe during pregnancy
Vaginal probe in the 1st trimester
Abdominal probe >12 weeks
39
X-rays
Fetal bones not visible until >14 weeks of gestation
| X-rays hazardous to embryo & fetus
40
follow-up visits
second timester - 1 month
third trimester- 1 x month
36 weeks beyond - 1 x week
after 40 weeks - 2 x weeks
41
fluid loss DDX
Amniotic fluid (“rupture of membranes”)
Urine
Blood
42
ROM
rupture of membranes
43
too much amniotic fluid
polyhydramnios
44
too little amniotic fluid
oligohydramnios
45
Premature rupture of membranes (PROM)
Defined: rupture of membranes before labor
Preterm: before 37 weeks
Prolonged: >18 - 24 hours
46
PROM
Common: 5 – 10 %
Cause: unknown
Risk factors: similar to preterm labor
47
Diagnosing PROM
Immunochemistry tests (dipstick format)
Sterile speculum examination
48
Immunochemistry Tests
AmniSure
Placental alpha microglobulin-1
Actim Prom
Insulin-like Growth Factor binding protein-1
49
Determine ph of fluid
Nitrazine strip commonly used
Acidic (<7.0) = probably urine
Basic (>7.0) = probably amniotic fluid
50
Sterile Speculum Examination
Look for pooling of fluid on posterior blade of speculum
Determine ph of fluid
Nitrazine strip commonly used
Acidic (<7.0) = probably urine
Basic (>7.0) = probably amniotic fluid
Look for ferning on microscope slide
Culture fluid if labor not imminent or desirable
51
Preterm Labor
labor between 22 -36 weeks
52
THE single most important cause of:
Perinatal deaths
Neonatal morbidity
Preterm Labor
| Incidence: 11 – 12 %
53
Preterm Labor Risk Factors
```
Major Risks:
Prior preterm labor 6-8x
Multiple gestation 6-8x
African-Americans 3-4x
Low socioeconomic status 1.9-2.6x
```
54
Minor risk factors for preterm labor
```
Poor weight gain
Physical work
Smoking
Anemia
Bacturia
Bacterial vaginosis
Systemic infections
Age < 17 or >40
Multiple abortions
DES exposure
Uterine abnormality
Short stature
Low pre-pregnancy weight
```
55
DES
```
DES = diethylstilbesterol
Synthetic estrogen (1930s)
```
56
The DES Story
Used 1947 – 1968 to treat or prevent:
Miscarriages, low birth weight, poor OB outcome
Shown by 1952 to not be helpful
Shown by 1968 to cause increased risk of:
Vaginal cancer
Miscarriages, ectopic pregnancy
Premature labor, infertility
57
Bacterial Vaginosis
```
Gardnerella vaginalis in vaginal flora
Common: 15 – 40%
Asymptomatic or may cause vaginitis
Treatment:
Metronidazole oral or vaginal gel
Clindamyicn vaginal cream
```
58
Early Detection of Preterm Labor
```
Risk scoring systems
Home contraction monitoring
Salivary estriol
Screening for bacterial vaginosis
Fetal fibronectin (in maternal serum)
Absence = low risk
Presence = increased risk
```
59
Cervical length by ultrasound
If cervix >25 mm, risk of preterm labor is very low
60
Fetal fibronectin
protein that's believed to help keep the amniotic sac "glued" to the lining of the uterus. ... If your health care provider is concerned about preterm labor, he or she might test a swab of secretions near your cervix for the presence of fetal fibronectin between week 22 and week 34 of pregnancy.
61
Predicting Risk of Preterm Labor
Cervical length by ultrasound
If cervix >25 mm, risk of preterm labor is very low
Fetal fibronectin
If not found in cervical/vaginal secretions, risk of preterm labor is very low
62
Prevention of Preterm Labor
Reduce risk factors when possible
Supplemental progesterone treatment
Vaginal progesterone
Injections of 17-OH progesterone
63
Preterm Labor Treatment
Glucocorticoid therapy when <34 wks
| Tocolysis to delay delivery 1-2 days
64
Glucocorticoid therapy when <34 wks
Betamethasone 12 mg IM q24 h x 2 doses
| Dexamethasone 6 mg IM q 6h x 4 doses
65
Tocolysis to delay delivery 1-2 days
Allow transport to appropriate center
| Allow time for glucocorticoid therapy
66
Labor
Labor = regular contractions which cause changes in the cervix
Effacement (in percent)
Dilation (in cm)
67
Tocolysis
Calcium channel blockers (like nifedipine)
Magnesium sulfate
Beta-2 sympathomimetics (“B-mimetics”)
Ritodrine, terbutaline
Others
Oxytocin analog (Antosiban)
Prostaglandin synthetase inhibitors
Ethanol
68
Neonatal Survival Estimates
```
Gestational Age
< 22 weeks <1%
22 – 24 weeks 5-10%
26 – 28 weeks 50-90%
28 – 34 weeks 90-99%
>34 weeks 99%
```
69
Morbidity with Prematurity
Respiratory
Respiratory:
RDS (respiratory distress syndrome)
Chronic lung disease
70
Morbidity with Prematurity
GI
Necrotizing enterocolitis
71
Morbidity with Prematurity
Neurologic
Cerebral palsy
| Intraventricular hemorrhage
72
Morbidity with Prematurity
visual
retinopathy
73
Apgar scores
```
color
pulse
reflex /irritability
muscle tone
breathing
```
74
Apgar scores (0 points)
```
color - blue all over
pulse - absent
reflex /irritability - no response
muscle tone - none
breathing - none
```
75
Apgar scores (1 ooint)
```
color - body pink/limbs blue
pulse - < 100 per min
reflex /irritability - grimace/feeble cray
muscle tone - some flexion
breathing - weak/irregular
```
76
Apgar scores (2 points)
```
color - pink all over
pulse - > 100 per min
reflex /irritability - cough, pulls away
muscle tone - active movement
breathing - strong
```
77
Epidemiology of Diabetes
Affects 5-7% of the U.S. population
Corresponds to 15-20 million people
1-2 million have Type I diabetes
The rest have Type II
78
Most Type II diabetics are
> age 25 at diagnosis
79
Most Type I diabetics are
< age 25 at diagnosis
80
Pathophysiology Type I
Abrupt (weeks, months) loss of pancreatic beta cells
81
Pathophysiology Type II
Insulin resistance
| Gradual (years) loss of beta cells
82
Complications (diabetes)
Death from acute ketoacidosis
```
Increased risk of:
Cardiovascular disease
Renal disease (nephropathy)
Vision loss (retinopathy)
Nerve conduction disorders (neuropathy)
```
83
Diabetic Obstetrical Issues
Birth defects
Late pregnancy intrauterine fetal death (stillbirth)
Large fetal size (macrosomia)
> 10 lbs
Birth trauma risk (esp. shoulder dystocia)
84
Diabetes Treatment Strategy
Birth defects
Late pregnancy intrauterine fetal death (stillbirth)
Large fetal size (macrosomia)
> 10 lbs
Birth trauma risk (esp. shoulder dystocia)
Tight glucose control
Multi-dose insulin
Diet, exercise
Coordinated programs (“Sweet Success”)
Early delivery (37-39 weeks)
85
Insulin/Glucose Changes in Pregnancy
First Trimester
Insulin secretion and sensitivity rise
Fasting glucose fall (15 mg/dL)
Effect peaks at 12 weeks
86
Insulin/Glucose Changes in Pregnancy
Second Trimester
Insulin sensitivity falls 33 – 50%
Fasting & postprandial glucose levels rise
Due to Human Placental Lactogen (HPL)
Prolactin & cortisol may contribute
87
Insulin Requirements in Pregnancy
Stable or may drop in first trimester
Begins to rise in second trimester
Ultimately 2-3 times as much insulin may be needed in the 3rd trimester as was required before pregnancy
88
Gestational Diabetes
Glucose intolerance seen during pregnancy
No history of diabetes before pregnancy
Normal glucose tolerance after pregnancy
Best viewed as a variant of Type II diabetes
89
Gestational Diabetes Treatment
Diet
Add insulin if needed
Use insulin sensitizing drugs such as metformin
