Preterm Birth and Preterm Labor

NURS546

What is defined as periviable gestation?

20-25+6 weeks gestation

What is defined as extremely preterm?

26-27+6 weeks gestation

What is defined as very preterm?

28-31+6 gestational weeks

What is moderate preterm?

32-33+6 weeks gestation

What is late preterm?

34-36+6 weeks gestation

What is allostatic load and why is it a good thing to know about as a midwife?

The cumulative cost to the body of allostasis (organisms actively adjust to both predictable and unpredictable events). Serious pathology can occur. This is good to know as a midwife because we need to understand how the lived experience has an impact on pregnancy and health.

What is weathering?

The term weathering describes the constant stress of racism that leads to premature biological aging. The impact of stress and weathering happens way before pregnancy begins.

What are some causes of preterm labor?

tobacco, alcohol, drug use, cocaine, diet, employment, exercise, douching, stress, anxiety, racism, discrimination

What are some pathophysiological mechanisms that cause preterm labor?

Premature activation of the hypothalamic-pituitary-adrenal (HPA) axis, inflammation/infection, decidual hemorrhage, over distention of the uterus, genetics

How is the HPA axis is prematurely activated?

physical stress, psychological stress→release high levels of corticotropin-releasing hormone (CRH)→prostaglandin production, uterine stimulation. genetic factors, inflammation, infection.

What can cause overdistention of the uterus?

multifetal gestation and polyhydramnios

How do we diagnose preterm labor?

Gestational age 20-37 weeks, regular uterine ctx > 6/hour AND at least one: ROM, cervical change, and cervix 3cm dilated or 80% effaced.

What is the most significant risk factor for PTB?

Hx of PTB

What are some strategies we can use to prevent PTB?

cervical length screening, vaginal progesterone or 17-OHPC, and cerclage.

What are cerclages?

Used for cervical insufficiency. Prophylactic cerclage usually done at 12-14 weeks, rescue cerclage can be done when cervix changes are already detected.

How can we predict preterm birth?

Fetal fibronectin, cervical length, estriol levels, symptoms eval, and education

What is fetal fibronectin?

Trophoblast glue: promotes adhesion at uterine-placental and decidual-fetal membrane interfaces.

What are some ways we can prevent PTB?

Low dose aspirin (1st trimester-36+6), supplemental progesterone (might be helpful), quit smoking, no cocaine, cervical cerclage, diagnose and treat infection.

What do we do if a patient comes in through triage with PTL symptoms?

EFM, collect FFN, collect GC/chlamydia cultures, collect GBS culture, cervical exam, collect UA/C&S, get a good history.

What are some health inequities we have to consider when taking care of our patients?

Access to health care, socioeconomic factors, education, medical factors, behaviors, genetics and stress

What causes health disparities for black parents?

Racism

How do health inequities work to lead to preterm birth?

Upstream causes (systemic/structural racism), midstream causes (unfair treatment), downstream causes (health harming exposures and conditions), and biological mechanisms (neuroendocrine, immune function, inflammation, infection, microbiota, vascular effects)

What is tocolysis?

Medications used to inhibit myometrial contractility.

Who cant get tocolysis?

People who have IUFDs, lethal fetal anomalies, non-reassuring fetal heart tones, severe IUGR, chorioamnionitis, hemorrhage and severe pre-e/eclampsia

What medication do we use for tocolysis and how do they work?

Magnesium sulfate (not that effective, reduces risk of cerebral palsy in PTB) corticosteroids (enhance maturation of lungs, max benefit @ 48 hours), indocin, and nifedipine

What is a lab that we cant miss when someone comes in with PTB symptoms?

Fetal fibronection (FFN)

What is Kangaroo Care?

After birth the mother would do skin-to-skin contact with baby, baby wears hat and diaper, baby in flexed, fetal position, and tightly bundled)