health challenges in labour and birth Flashcards
why is the rate of preterm births increasing?
- average age of mothers is older
- fertility treatment more common
- increasing role of infection
what are some factors that may contribute to preterm labour?
- inflammation
- race
- toxicology
- stress
- nutrition
- cervical surgery
- uterine distension
- genetics
- previous PTB
what is fetal fibronectin and why is it tested for?
- it is a glycoprotein released into cervical/vaginal fluid in response to inflammation or separation of amniotic membranes
- normally is present until 22 weeks and then not again until time of labour
- a negative test means it is 98% likely a pregnancy will continue at least 2 more weeks
- positive test between 24-34 weeks could indicate risk of preterm labour
- negative is a more definitive result than a positive
what are some strategies to avoid stimulation that could trigger or progress preterm labour?
- minimal or no vaginal exams as they can stimulate and increase risk of infection
- no sex
- no nipple stimulation
- keep bladder empty
some other interventions that may or may not be helpful vs the risk:
- bedrest
- IV hydration
- MgSO4
- Sedation
what do tocolytic drugs do?
they are medications that stop contractions
what are some common tocolytics used to slow or stop preterm labour?
- indomethacin (anti-prostaglandin)
- Nifedipine (calcium channel blocker)
- progesterone
how does indamethacin work as a tocolytic?
- it is an anti-prostaglandin and inhibits uterine activity
- effective short-term at delaying delivery 48 hours or so
- ideal for creating window to give corticosteroids or MgSO4 for health of fetus
what tocolytic is appropriate for long-term prevention of preterm labour?
progesterone
what is cervical insufficiency?
-when there is premature, painless dilation of the cervix without contraction between 20-28 weeks
why may corticosteroids be given during preterm labour?
-to decrease prenatal mortality, the risk of respiratory distress syndrome and intraventricular hemorrhage
what medications are given to “mature” the lungs of a preterm infant?
- corticosteroids
- usually betamethasone (12mg IM q24h x2) or dexamethasone (6mg IM q12hr x4)
why may MgSO4 be given during preterm labour?
- new evidence suggests that there is a neuroprotective effect
- women less than 37 weeks gestation could be given this once dilated to or greater than 4 cm
- given a 4g loading dose over 30 min and then 1g/hr until delivery
what are some possible causes of bleeding during pregnancy?
- spontaneous abortion
- ectopic pregnancy
- gestational trophoblastic disease
- placenta previa
- abruption placentae
- uterine rupture
what criteria defines spontaneous abortion?
- occurs naturally
- expulsion of fetus before 20 weeks gestation or expulsion of a fetus weighing less than 500 g
what are some interventions that may be done if a spontaneous abortion occurs?
- give a drug to contract uterus (cytotec, RU486, cervidil)
- give winrho if mom is rH -ve to prevent development of antibodies
- IV therapy or blood transfusion if needed
- dilation and curettage if needed
- dilation and suction evacuation if needed
- providing physical and emotional support
what is an ectopic pregnancy?
-when a fertilized ovum implants outside of the uterus
95% of ectopic pregnancy end up in the fallopian tube, but are risks and symptoms associated with this?
- sharp unilateral pain
- decreased BP
- syncope
- referred shoulder pain, lower abdominal pain
- vaginal bleeding
- rupture of tube if interventions not done before then
what is gestational trophoblastic disease?
- a rare condition where abnormal development of the placenta occurs
- trophoblastic cells obliterate the pregnancy
- sometimes called molar pregnancy
- can develop into choriocarcinoma
what are signs of gestational trophoblastic disease?
- classic signs of pregnancy, but exaggerated, excellerated, and exacerbated
- uterine enlargement greater than gestational age
- vaginal bleeding and passage of clots
- hyperemesis gravidum
- development of hypertension before 24 weeks
what is an antepartum hemorrhage?
- vaginal bleeding that occurs after 20 weeks gestation
- 2 main causes are placenta previa and abruptio placentae
- can also have uterine or cervical causes
what is the blood flow to the uterus and placenta?
700-1000 mL/min
what is the major maternal risk if the vascular integrity of uterus/placenta is disrupted during late pregnancy?
-exsanguination within 8-10 minutes
how common is placenta previa?
4/1000 births
how common is abruptio placentae?
1/100 births
what is placenta previa?
when the location of the placenta is low and partially obscures the cervical opening
what are the types of placenta previa?
- total/complete
- partial
- marginal
- low-lying placenta (not actually obscuring, but dangerously close to cervix)
what kind of delivery is required if a woman has placenta previa?
a c/s
what is the major risk associated with placenta previa?
bleeding
how is placenta previa typically diagnosed?
-by ultrasound - either routine or when bleeding occurs and is invstigated
why does placenta previa require frequent monitoring?
because 80% of the time the placenta moves - this can mean it gets better or worse
what are some risks of developing placenta previa?
- previous placenta previa
- uterine abnormalities
- endometrial scarring
- large placental mass
when bleeding occurs because of placenta previa, what is it typically like?
- always visible bleeding
- will be bright red
- usually not painful
what is abruptio placentae?
- the premature separation of a normally implanted placenta from the uterus wall
- aka separates before delivery as opposed to after
what is the outcome of a total or complete abruptio placentae?
maternal hemorrhage
fetal death
what is the outcome of a partial abruptio placentae?
- depends how much separation
- a fetus can tolerate up to 30-50% abruption
what can cause abruptio placentae?
- short cord
- hypertension
- blunt abdominal trauma
- crack/cocaine use
- PPROM
- overdistended uterus
- previous C/S
- short interpregnancy interval
- smoking, especially more than 1 pack per day
- uterine abnormalities
- advanced maternal age
what are some negative maternal implications of abruptio placentae?
- intrapartum/postpartum hemorrhage
- DIC
- Hemorragic shock
what is vasa previa?
- when vessels of umbilical cord divide some distance from placenta in placental membranes
- torn vessels can lead to fetal hemorrhage and non-reassuring fetal status
what are possible symptoms of abruptio placentae?
- decreased BP
- pain in abdomen
- may or may not be visible bleeding, it can be obscured
what is uterine rupture?
-spontaneous rupture of uterus or rupture of a previous scar
what are risk factors for uterine rupture?
- previous uterine surgery, including C/S
- short interdelivery interval (less than 18 months)
- grand multiparity
- trauma
- intrauterine manipulation
- midforceps rotation of fetus
- attemptin VBAC and given oxytocin
what are symptoms of uterine rupture?
- may be initially asymptomatic
- abdominal pain not relieved by analgesia
- dilation ceases
- vomiting
- syncope
- vaginal bleeding
- maternal/fetal tachycardia
- abnormal FHR
- fetal parts palpable through abdominal wall
- dramatic, sharp, tearing pain
what is DIC?
- disseminated intravascular coagulation
- occurs when clotting factors initially increase, uses up platelet and clotting factors making microclots
- then, serious bleeding can occur inside the body or outside
- very life-threatening
