Parturition: Pre-term birth

Question 1

What is a pre term birth

note leading cause of perinatal mortality in normal babies and is associated with an enormous cost

Answer 1

< 37 weeks
< 32 weeks very pre term

is an abnormality of quiescence. uterus can not stay ‘quiet’ enough for as long.

Question 2

What gestation and birth weight do we expect from pre term babies with a high survival rate?

Note survival isn’t only thing to consider. (major or moderate handicap)

Answer 2

28-29 weeks

1250g

Question 3

What are some causes of prematurity?

Answer 3

Stress affecting endocrine function (uterus, quiescence)
Bleeding
Infection
Stretch

Question 4

Why my quiescence fail?

Answer 4

Unsure, however infection seems to be a potent stimulator.

Question 5

Pre term activation

Answer 5

Uterine stretch, fetal genome, upregulation of myometrium, membrane rupture
Cervical change from parity

Question 6

Infection and cervix. Preterm

Answer 6

Infection or exarcebation of inflammatory cervical ripening can quicken process, potentially leading to pre term birth

Question 7

What are some triggers physiologically that may cause preterm babies?

Answer 7

Stretch: myometrial distension and membrane disurption
Tissue damage (cervix)
Infection
Abnormal placentation: Bad growth, prostaglanding release, progesterone

Question 8

What are some complications associated with a preterm birth

Answer 8

Malpresentation (e.g breech)
immature, unwell fetus
maternal co-morbidities
C sections, complex
recurrent pre term birth

Question 9

What are the two ways in which we get pre term babies and why?

Answer 9

50% spontaneous: infection, cervical or uterine change, fetal change.

50% iatrogenic: IUGR or maternal disease (e.g. preeclampsia)

Question 10

Predictors of preterm birth

Answer 10

Pervious PTB (obstetric history)
smoking
multiple pregnancy
cervical surgery
uterine anomaly
polyhydroamnios

Question 11

What is fetal fibronectin?

Answer 11

A glycoprotein that holds the decidua and chorion together.
Not supposed to seen after first trimester in cervico-vaginal fluid. (20-36 weeks)
If seen, can maybe show risk of pre term.

Can test for people in preterm labour. If negative, 99.5% chance won’t deliver in next 7-10 days. If positive, 30% chance they will. Can decide to treat with steroids

Question 12

What is tocolysis and what are some drugs used?

Answer 12

A mean to suppress preterm labour.

Drugs: Calcium channel blocker like nifedipine. Used to use salbutamol (B2 agonist)

Question 13

Why use corticosteroids?

use if delivery likely

Answer 13

Reduce neonatal disease from respiratory distress.
Less brain bleed and less gut in neonatal gut.
Betamethasone

Question 14

Why use magnesium sulphate?

use if delivery likely

Answer 14

6 hours before birth for preterm under 30 weeks, lowers chance of cerebral palsy

Question 15

How might you manage risks of preterm babies?

Answer 15

Limit the risks: Lifestyle so smoking cessation, cervical change, drug therapies. Progesterone(unsure) and cerclage may be of benefit

Typically teats effects but not causes.

Question 16

The _____ ____ is the most powerful predictor of pre term

Answer 16

cervical length