Tobacco Use in Pregnancy

Tobacco remains the leading cause of preventable disease, disability, and death in the USA, despite overall decreasing rates of smoking!

• 14% of US adults smoke cigarettes. This rate is lower in pregnancy, around 7.2%; however, young women are a high risk group for cigarette smoking compared to the general population.

• Tobacco use in pregnancy specifically is linked to higher risk of:

  • Ectopic pregnancies

  • Cleft lip/palate

  • Fetal growth restriction and low birth weight (13-19% of term infants with tobacco exposures)

  • Placenta previa

  • Placental abruption

  • PPROM

  • Preterm delivery (5-8% attributable risk)

  • Increased perinatal mortality (5-7% attributable risk)

  • Increased risk of sudden infant death syndrome (22-34% attributable risk)

• Tobacco use also has lifelong health implications!

  • Pregnancy can be a great motivator to quit smoking and make significant changes for lifelong health -- 54% of those who smoke during/pre-pregnancy will quit at least for pregnancy!

• Data regarding e-cigarettes/vaping, cigars, and hookah are limited, though are also risky.

  • However, these may have somewhat different risks, though many (particularly hookah and vaping) are perceived to be safer -- they are not!

  • The CO 807 has a great table comparing amounts of nicotine in each varying method of consumption -- worth keeping handy when you’re looking to prescribe/suggest replacement therapy:

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ACOG CO 807

How do I intervene as a clinician?

• Ask!

  • Be sure to ask about alternative forms of nicotine consumption as well -- patients may not disclose vaping/hookah/etc. Use unless specifically asked. 

• Use motivational interviewing techniques

  • Cognitive behavioral therapy and motivational interviewing are beneficial to initiate and sustain tobacco use cessation.

  • Even if not ready to quit, consistent motivational approaches may be beneficial over time.

• You can use a tool, like the 5As:

  • Ask -- characterizing use at the same time

  • Advise -- if still using, provide advice about risks of continued use

  • Assess -- whether patient is willing to quit. This can be continued with motivational strategy at future visits if not ready at the first.

  • Assist -- if ready to quit, provide materials and options to help get the quit started. Suggest importance of having a tobacco-free space at home, seeking out a “quitting buddy,” and/or using a service like 1-800-QUIT-NOW to provide ongoing support.

  • Arrange -- continue follow up visits to track/encourage success 

• 50-60% of those who quit smoking during pregnancy will resume within 1 year postpartum.

  • Keep up and continue to ask at future visits.

  • Encourage whole family to quit smoking as well to have family-motivated success.

Pharmacotherapy for tobacco cessation

• If used during pregnancy, note data is limited for most methods. 

• Nicotine replacement:

  • Provide a stable, controlled dose of nicotine in the form of gums, patches, or lozenges

    • Gums may provide some benefit psychologically due to oral fixation

  • Have not been demonstrated to be effective in pregnancy, unfortunately.

    • Any planned use should be with clear resolve of patient to quit in mind, as these methods still deliberately expose maternal-fetal dyad to nicotine and likely some continued form of risk.

• Pharmacologic cessation agents

  • Varencicline (Chantix)

    • Dose pack to start therapy.

    • Partial agonist for nicotinic receptors in brain

    • Limited data in pregnancy, but that which exists does not demonstrate teratogenicity.

  • Bupropion (Wellbutrin)

    • Most studies have looked at a dose of 150mg BID for 7-12 weeks.

    • Antidepressant

    • Also limited data in pregnancy, but no known risk of fetal anomalies or adverse pregnancy outcomes.

Delayed Umbilical Cord Clamping

Reading: CO 814 https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2020/12/delayed-umbilical-cord-clamping-after-birth 

Delayed Cord Clamping - An Overview

• Small studies initially demonstrated 80-100cc of blood transferring from the placenta to the newborn within 3 minutes after birth, and

• 90% of that blood volume transfer is achieved within just a few breaths in healthy term infants.

  • A 3kg infant (6lb 10oz) has a typical blood volume of around 250 cc… so the difference is potentially huge!

• Modern studies of “delayed” cord clamping is usually defined as 30-60 seconds of delay after birth to clamp the cord, and shows benefits for both term and preterm infants.

• For term babies:

  • Improved hemoglobin levels

  • Improved iron stores (lasting even to a few months of life) → potentially favorable neurodevelopmental outcomes

• For preterm babies:

  • Reduced rates of IVH and NEC

  • Lower risk of transfusion

• Basically for these reasons, most organizations across the world recommend 30-60 seconds of DCC for most term and preterm infants, though the range ca be up to 5 minutes (ACNM). 

  • ACOG specifically recommends 30-60 seconds of DCC for vigorous term and preterm infants. 

• Are there concerns? Theoretically, yes:

  • Perhaps delayed cord clamping delays resuscitation for babies who need it?

    • Sick/preterm babies may actually benefit from placental transfusion as the placenta continues gas exchange after delivery while still attached!

  • Maybe delayed cord clamping causes polycythemia or jaundice?

    • No solid evidence of this in preterm infants

    • Perhaps some evidence in term infants, but slight.

What’s the evidence?

• Studies of Doppler sonography during DCC have demonstrated marked increase of placental transfusion during those breaths.

  • The extra iron load provided by DCC here has been shown to reduce/prevent iron deficiency through 1 year of life.

  • Iron deficiency has been linked to cognitive, motor, and behavioral developmental delays that may be irreversible.

    • Iron deficiency is definitely prevalent in low-income countries, but also common in higher income countries too! (5-25%)

  • Additionally, that blood and plasma volume will transfuse over immunoglobulins and stem cells, which may be of particular benefit to preterm babies.

• In preterm infants:

  • Systematic review of 15 trials of 738 infants demonstrates DCC over immediate clamping leads to:

    • Fewer transfusions for anemia (RR 0.61)

    • Lower risk of IVH (all grades, sonographic dx) (RR 0.59)

    • Lower risk of NEC (RR 0.62)

• In term infants:

  • Systematic review of 15 trials involving 3911 women and their singleton infants:

    • DCC had higher immediate hemoglobin levels (2.17 g/dL difference) and to 24-48h after birth (1.49 g/dL)

    • At age 3-6 months, immediate clamping had a RR of 2.65 for iron deficiency!

    • NO difference in rates of polycythemia or jaundice, but jaundice requiring phototherapy was slightly higher risk for DCC (2.74% vs 4.36%, RR 0.62).

    • Neurodevelopmental outcomes limited, but no difference versus slight benefit to DCC over ICC. 

      • Overall, seems to be beneficial for babies, at least in the immediate term, with more definite benefit for preterm infants.

• What about maternal risks?

  • Five trials of over 2200 women did not demonstrate any increased risk of PPH, estimated blood loss, difference in hemoglobin level, or risk of transfusion -- even at cesarean!

    • ACOG does caution though that with previa/abruption or other situations for high increased risk of hemorrhage, benefit versus risks of DCC should be weighed.

Can I screw it up?

In a word, yes. Here are some tips:

• Newborn care should proceed as usual.

  • Dry and stimulate for the first breath/cry, maintain normothermia with skin-to-skin contact.

    • Positioning on the chest/abdomen (versus holding infant at level of introitus or lower) doesn’t seem to have an effect on the amount of blood transfused.

  • Clear secretions only if copious or obstructing the airway.

  • Even with meconium, DCC can continue as long as infant is vigorous.

• Continue with active management of 3rd stage.

  • Use uterotonics (oxytocin at this point, typically) to minimize bleeding

• Use common sense on when to not use DCC.

  • If maternal hemodynamic or neonatal stability is of concern, then DCC should not be continued.

• If you need/plan to get umbilical cord gases:

  • Studies are mixed here. A definitive study would be nice, if you’ve got some funding opportunities around you!

• Milking the cord -- don’t do it!

  • It seems to make some sense -- if we push blood faster through the cord, we get the transfusion benefit of DCC in less time -- perhaps some use for the infant in need of resuscitation or extreme prematurity?

    • A recent study of infants undergoing milking at extreme prematurity (23-27 weeks) was halted early due to higher risk of IVH in the milking group compared to DCC.

      • ACOG recommends not milking at under 28 weeks gestation.

    • Prior studies to this including infants of later gestational ages, that showed some potential benefit to hemoglobin levels, but were overall mixed. ACOG interprets this as no definitive evidence for milking at greater that 32 weeks -- but we’d recommend against it at this point, given the pretty definitive risk of harm for premature infants at least.

• If patient desires cord blood banking… reconsider.

  • Cord blood banking success is significantly decreased when there is a 60 second delay in DCC.

  • Families considering banking should be aware of this risk… 

    • It’s arguable that DCC may have more benefits than cord blood banking. 

Anemia in Pregnancy

Be sure to check out the new ACOG Practice Bulletin #233 on anemia — first time it’s been updated in a while! And while you’re at it, check out our old episode on sickle cell anemia.

Physiologic Changes in Pregnancy to Blood Volume 

• Definitions

  • Remember that anemia in pregnancy is defined as: 

    • Hgb <11 g/dL in the first and third trimester 

    • Hgb <10.5 g/dL in the second trimester 

    • Previously, ACOG had discussed a lower threshold for certain people based on race, but one important study found that this lower threshold likely contributes to the perpetuation of racial disparities in medicine without a scientific reason for lower Hgb 

• What happens in pregnancy? 

  • Physiologic

    • Plasma volume expands by 40-50%

    • Erythrocyte mass expands by 15-25% 

    • So even though there is increased red cell mass, it seems overall that HCT % goes down 

  • There is also increased iron requirement, so it is more likely for people to become iron deficient 

Causes of Anemia in Pregnancy 

• Acquired 

  • Deficiency 

    • Iron deficiency - by far the most common 

    • B12 deficiency 

    • Folic acid deficiency 

  • Hemorrhagic 

  • Anemia of chronic disease 

  • Acquired hemolytic anemia 

  • Aplastic anemia 

• Inherited 

  • Thalassemias 

  • Sickle cell 

  • Hemoglobinopathies 

  • Inherited hemolytic anemias 

Work-up of Anemia in Pregnancy 

• Screening 

  • All pregnant people should be screened for anemia with CBC in the first trimester and again right before third trimester (usually 24-28 weeks) 

  • Also, should have discussion with everyone about screening for hemoglobinopathies if they have not been screened before 

• Work up of asymptomatic with mild to moderate anemia: 

  • Anemia type: microcytic vs normocytic vs macrocytic 

    • Microcytic (MCV < 80 fl) 

      • Most commonly: iron deficiency 

      • But can also be caused by thalassemias, anemia of chronic disease, sideroblastic anemia, etc. 

    • Normocytic (MCV 80-100fL) 

      • Hemorrhagic or early iron deficiency = common 

      • Others: anemia of chronic disease, bone marrow suppression, chronic renal insufficiency, hemolytic anemia 

    • Macrocytic (MCV > 100 fL) 

      • Folic acid deficiency, B12 deficiency = most common 

      • Others: Reticulocytosis, liver disease, alcohol abuse, drug-induced hemolytic anemia 

• Iron studies with measurement of red blood cell indices, serum iron levels, ferritin levels 

  • Some places also include a total iron-binding capacity 

  • In someone with iron deficiency, iron levels and ferritin will be low, while TIBC will be high 

• Peripheral blood smear 

• Can also look at vitamin B12 and folate levels if macrocytic 

• Other work-up: 

  • If not responding to treatment with iron, folate, or B12, then further workup should be done 

  • Ie. is there a reason for malabsorption (gastric bypass?) 

  • Is there a reason for blood loss? 

Treatment of Anemia in Pregnancy 

• Iron deficiency 

  • Can start with oral iron, unless there is a reason for malabsorption 

    • Usual requirements: 27 mg daily during pregnancy, and usual diet will live 15 mg of elemental iron/day 

    • Most oral forms of iron will exceed this 

    • If unable to tolerate oral iron or has reasons for malabsorption, can do IV iron, which can come in the form of iron dextran, ferric gluconate, or iron sucrose 

• Folate or B12 deficiency

  •  MCV > 115 is almost exclusively seen in people with folate or B12 deficiency 

  • Give folate or B12! 

  • Folic acid: 400 mcg/day unless there are other indications for increased folate (ie. history of neural tube defect affecting child, on anti-epileptics) 

  • B12: usually only seen in people with gastric resection or Crohn disease 

    • Usually given IM every month, 1000 mcg/injection 

• Other causes 

  • Depending on the cause, may need to work with colleagues from other specialties 

  • Or your friendly neighborhood MFM 

• A word on transfusion 

  • Hgb <6 g/dL have been associated with abnormal fetal oxygenation 

  • Usually recommend transfusion if Hgb <7 or if symptomatic 

  • However, can consider higher threshold if other co-morbidites (ie. sickle cell anemia with known crises if Hgb <7) 

Obesity and Pregnancy

Definition and Epidemiology

• Obesity - classified by BMI 

  • Prevalence of obesity has increased to 34.0% in women 20-39 years in 2010  

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ACOG PB 230

Effect of Obesity on Pregnancy 

• Pregnancy Loss 

  • Increased risk of SAB (1.2 OR) and recurrent miscarriage (OR 3.5) 

  • Also have increased risk of pregnancies affected by neural tube defects, hydrocephaly, and other anomalies 

• Pregnancy Complications 

  • Antepartum

    • Medical issues: increased risk of cardiac dysfunction, proteinuria, sleep apnea, nonalcoholic fatty liver disease 

    • Pregnancy issues: increased risk of gestational diabetes, preeclampsia, stillbirth 

      • Risk of stillbirth increases with increasing obesity

        • OR 1.71 for BMI 30-34.9

        • OR 2.0 for BMI 35.0-39.9

        • OR 2.48 for BMI >40

        • OR 3.16 for BMI > 50

      • Of note, the practice bulletin does point out that black pregnant people with obesity have a higher risk of stillbirth than white pregnant people - discusses that while this is not a biological reason, is a proxy for likely negative influence of racism on health 

  • Intrapartum

    • Increased risk of cesarean delivery, failed trial of labor, endometritis, wound rupture/dehiscence, and venous thrombosis  

    • Decreased likelihood of VBAC after TOLAC 

  • Postpartum Complications - increased risk of future metabolic dysfunction 

  • Fetal complications - increased risk of growth abnormalities 

• How Can We Manage Obesity Before And During Pregnancy 

• Pre-pregnancy Counseling 

  • Discussion of control of obesity with weight loss (either surgical or non-surgical) 

  • Even small weight loss can be associated with improved outcomes (even 5-10%) 

  • Can try motivational interviewing 

    • Encourage diet, exercise, and behavior modification 

  • Medications 

    • Not recommended pre-pregnancy or during pregnancy 

• During Pregnancy 

  • Recommended weight gain 

    • Overweight: recommend 15-25 lb weight gain 

    • Obese: recommend 11-20 lb weight gain 

    • There is a lack of data regarding short-term and long-term maternal and newborn outcomes, no recommendation for lower targets for pregnant women with more severe degrees of obesity 

  • Congenital Anomalies

    • As previously discussed, increased risk of congenital anomalies, but detection of these anomalies is significantly decreased with increasing maternal BMI 

    • Cell-free DNA test failures are also more frequent in patients that are obese. This is because a minimum fetal fraction of 2-4% usually is needed. The median fetal fraction between 10-14 weeks is around 10%, but with increasing BMI, it’s associated with decreased fetal fraction. 

    • Can consider repeating screening if it’s because of early gestation, but not recommended if there are ultrasound findings of anomalies 

  • Metabolic Disorders - screen for glucose intolerance and OSA at first antenatal visit with history, exam, and labs 

    • Sleep medicine evaluation 

    • Can consider early glucose screening; if negative, repeat at usual time of 24-28 weeks 

  • Stillbirth and Antepartum fetal testing 

    • This is going to be different based on your institution 

    • Can consider weekly testing after 37 weeks for BMI 35-39.9 

    • Can consider weekly testing after 34 weeks for BMI >40 

• Intrapartum 

  • Many studies that show an increased risk of C-section among overweight and obese women 

    • There are studies that show an increased length of time in labor; another study showed that maternal BMI was not associated with longer second stage 

    • Maybe consider allowing more time in first stage of labor before C-section in obese individuals? 

    • Remember that pregnant women with higher BMI have a higher rate of complications with elective repeat cesarean section - so not a reason to not TOLAC them! 

  • Some considerations during labor 

    • Consider anesthesia consult - especially if OSA. An epidural may be technically more difficult to place 

    • Antibiotics - may need to increase the amount of Ancef before C-section (remember usual is 2g). Increase to 3g if >120 kg 

• Postpartum 

  • There is an increased risk of VTE in obese women, so definitely use your SCDs and encourage early mobilization  

  • In very high risk groups, discuss pharmacologic thromboprophylaxis 

    • Dose can be BMI stratified

      • BMI < 40: 40 mg Lovenox daily 

      • If BMI 40-59.9: 40 mg BID 

      • If BMI 60 or greater: 60 mg BID 

What Your Charge Nurse Wants You to Know: Feat. Julie Park, RN

It’s July, and with everyone moving up into new roles, we thought we’d think a bit about our nursing colleagues!

Today, we welcome Julie Park, an assistant nurse manager and labor and delivery charge nurse at the University of Washington Medical Center. She tells us a bit about her career in nursing, what a charge nurse is and what they do, and offers some tips for success for L&D clinicians and nurses of all experience levels.