Pregnancy Part 1 – SOGC 2014/ TN2014

Definitions:

• First Trimester = 0-12 wks          Second = 12-28 wks       Third = 28-40wks
• Term = 37-42
• Active Labour: regular contractions result in cervical change / descent of the fetus (presenting part)
• Gravity = # pregnancies of any gestation
• T = # of term infants P = # premature A = # of abortions L = # of living Children

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1 In a patient who is considering pregnancy:
a) Identify risk factors for complications.
b) Recommend appropriate changes (e.g., folic acid intake, smoking cessation, medication changes).

Preconception Counselling

• GA 3-8 wk is a critical period of organogenesis
• PMH – optimize medical illness

Supplements

• Folic acid supplement 8-12 wk preconception until end of T1
  • 0.4-1mg/d
  • 5mg/d if previous NTD, anti-epileptic meds, DM or BMI >35
• Iron supplement & prenatal vitamins

Risk Modification:

• Lifestyle: balanced nutrition & physical fitness
• Meds – ? teratogenic
• Infection screening: rubella, HBsAg, VDRL, Pap smear, G/C, HIV
• Genetic testing – appropriate for high risk group
• Social: EtOH, smoking, drug use, domestic violence (ask every women about abuse)

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Counselling:

Nutrition

• Ca 1200-1500mg/d + Vit D 1000 u – 3-4 servings of milk daily
• Daily caloric increase – 100 cal/d in 1st, 300 cal/d in 2nd, 450 cal/d in 3rd
  • Wt gain 6.8-18.2 kg (depends on pre-pregnancy weight)
• Advise all women of childbearing age to supplement diet with 0.4mg/day (5mg/d if high risk) Folic acid for the first 12 wk of(materna has 1 mg/day)
  • decreases indicence of NTD
  • Food rich in folic acid: spinach, lentils, chick peas, asparagus, brocoli, peas, brussels sprouts, corn and oranges
• Iron supplement (0.8mg/d in T1, 4-5mg/d in T2, >6mg/d in T3) if anemic, prenatal vitamins
  • Req amount > normal body stores & typical intake – need supplement iron
  • daily multivitamin not necessary in 2nd trimester (unless not consuming an adequate diet)
• Essential fatty acids – vegetable oils, margarines, peanuts, fatty fish
  • supports fetal neural and visual development

Caffeine – diuretic & stimulant

• 1-2 cups/d are safe during pregnancy (SOGC)
• <200mg/d is not thought to contribute to miscarriage or preterm birth / relationship to IUGR ? (AOGC)

Food Borne illnesses

• Avoidance of cats/litter/rodents (toxoplasmosis), soft cheeses/deli meats, smoked salmon, pates (listeria), raw fish / eggs / poultry, unpasteurized dairy products
• 0.5ppm of mercury in fish is not considered harmful – limit consumption of top predator fish, eg shark, swordfish, tuna (one meal / month)

Social Hx:

• EtOH – no amount is safe in pregnancy
  • encourage abstinence
  • ↑ SA, stillbirth, congenital anomalies (FAS)
• smoking – reduce or quit
  • ↑ low birth wt, placenta previa / abruption, SA, preterm labour, stillbirth
• Drug cessation
  • Cocaine ↑ microcephaly, growth retardation, prematurity, placenta abruption
• Inquire about safety, domestic violence, genetic disease
• Exercise
  • C/I: ROM, Preterm labour, HTN, Incompetent Cervic, IUGR, multiple gestations (>3), placenta previa >28wk GA, 2nd/3rd trimester bleeding, twin pregnancy >28wk GA
  • uncontrolled DM1 / thyroid dz, anemia (hgb <100) other CVS / Resp / endo disorders
• Work – strenuous work / extended hours and shift work – ↑ low birth weight, prematurity, SA
• Travel – not harmful, air travel ok in T2, cutoff GA36-38wk (depending on the airline)
• Intercourse – continue except
  • at risk for abortion, preterm labour, placenta previa
  • breast stimulation may induce uterine activity

PmHX

• heart conditions, past uterine/cervical procedures, STI’s
• maternal age, birth defects, multiple gestation

Med: 

• Review meds/OTC meds. – motherrisk.org
• Discuss cessation of current form of birth control

Family Hx:

• Genetic screening of high risk groups (tay-sachs, sickle cell, thalessemia)

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2 In a female or male patient who is sexually active, who is considering sexual activity, or who has the potential to conceive or engender a pregnancy, use available encounters to educate about fertility.

Discuss STI’s, appropriate forms of contraception, and emergency contraception.

Dx of pregnancy

Symptoms:

• amenorrhea – LMP, N/V, breast tenderness, u frequency, fatigue
• Nagele’s rule = 1^st day of LMP + 7days – 3 months.

Signs:

• Goodell’s sign – softening of the cervix (4-6wk)
• Chadwick’s sign – bluish discolouration of the cervix / vagina (6wk)
• Hegar’s sign – softening of the cervical isthmus (6-8wk)
• Uterine enlargment / breast engorgement

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3 In a patient with suspected or confirmed pregnancy, establish the desirability of the pregnancy.

Confirm pregnancy with urine/serum bHCG &/or US

1. Serum bHCG – positive 9 d post-conception
   • doubles Q1-2 d, peak 8-10wk, fall to a plateau until delivery
   • Less than expected
     • ectopic, abortion, inaccurate dates
   • Higher than expected
     • Multiple gestation, molar pregnancy, T21, inaccurate dates
2. Urine bHCG – positive 28d after LMP
3. US
   • Transvaginal
     • 5wk – gestational sac (bHCG >1500), 6 wk – fetal pole, 7-8 wk – fetal heart tones
   • Transabdominal 
     • 6-8wk – intrauterine pregnancy visible (bHCG – >6500)

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4 In a patient presenting with a confirmed pregnancy for the first encounter:
a) Assess maternal risk factors (medical and social). – objective 1
b) Establish accurate dates.
c) Advise the patient about ongoing care.

Repeat visits q4weeks until 28, q2weeks until 36, qweekly until delivery.

>2-3mo preconception	See Objective 1 Folic acid 0.4-1mg od + Iron Risk factors: Folic acid 5mg od Hx of baby with NTD, facial cleft, heart/urinary/limb defect Family hx of NTD, DM Smoking, obesity, poor diet, substance abuse, forgets to take vitamins daily Epileptics on valproic acid or carbamazepine
<12 wk	Routine Dating U/S for all pregnant women (SOGC 2014): First-trimester crown-rump length is the best parameter for determining gestational age the earliest ultrasound with a crown-rump length equivalent to at least 7 weeks (or 10 mm) should be used to determine the gestational age Between the 12th and 14th weeks, crown-rump length and biparietal diameter are similar in accuracy. It is recommended that crown-rump length be used up to 84 mm, and the biparietal diameter be used for measurements > 84 mm U/S more accurate than LMP dates if ≤ 23 weeks GA If a T2/3 scan is used to determine gestational age, a combination of multiple biometric parameters (biparietal diameter, head circumference, abdominal circumference, and femur length) should be used to determine gestational age, rather than a single parameter. (II-1A) When the assignment of gestational age is based on a T3  ultrasound, it is difficult to confirm an accurate due date. Follow-up of interval growth is suggested 2 to 3 weeks following the ultrasound. u/s dating reduces inductions for post-term pregnancies U/S also for Threatened abortion, incomplete abortion, prior to termination Suspected multiple gestation, ectopic pregnancy, molar pregnancy, and suspected pelvic masses Increased risk for major fetal congenital malformations
≥12 wk	routine FHR with handheld Doppler
>8 wk	Routine prenatal b/w: ABO group, Rh & Ab, CBC, HIV, rubella, syphilis, hep B sAg, Hep C ab, U/A, U Cx, urine for G/C, TSH (optional but routine in most places) VZV ab (if no hx of varicella), A1c for high risk of DM Aboriginal, hispanic, South Asian, Asian, African Prev Hx of GDM or glucose intolerance, macrosomia (>4000g), unexplained stillbirth, neonatal hypoglycemia, hypocalcemia, or hyperbilirubinemia Advanced maternal age >35yo, obesity, repeated glucosuria in pregnancy, polyhydramnios, suspected macrosomia, PCOS, acanthosis nigricans, corticosteroid use Visit 1: Fill out prenatal forms, refer if needed Inquire about financial concerns, living situation, paternity, abuse, stresses/supports (don’t forget to FIFE the patient). Visit 2: Physical Exam + Pap Smear, if not done in past 6mo & >21yo, vaginal swab for BV, cervical Cx for G/C
UTI	UTI and asymptomaic bacteriuria (midstream Cx >105 )Tx: Macrobid 100mg po bid x 7 days – avoid at labour and delivery due to hemolytic anemia TMP-SMX 1DS tab bid x 3 days (avoid 3rd trimester & near term) TMP 100mg bid x 7 days (avoid in 1st trimester) Amoxicillin 500mg tid x 7 days Clavulin 500mg bid x 7 days Keflex 250mg qid x 7 days Repeat U Cx in 1-2 wk after Tx
11-13wk + 6d	CVS prn, 1% risk of loss, earlier dx than aminocentesis1st trimester integrated serum screen – Part 1 – T18, 21 & U/S NTSIPS vs. IPS (SIPS + NT): Depending on the age(risk) of your patients and their desire for screening after informed consent. Amniocentisis may be offered after age 40 with no prior screening (http://www.bcprenatalscreening.ca/page202.htm)Indications for Nuchal Translucency U/S: Multiple gestation, age>40yo at EDD, Age>35 with >=3 SA Personal / family Hx of T18, 13, 21
16 wk	TA cut-off in most provinces
15-17wk	Amniocentesis – routinely offered to women >40yo & >35yo with multiple gestation; 0.5% risk of loss
15-20wk + 6d(16-18wk)	Part 2   or Quad screen (if no part 1) – T18, 21, ONTDs
18-24wk	Routine u/s for dates (inaccurate +/-2wk) /anomalies
≥20wk	SFH measurement routinely
24-26 wk	GDM screen: 1hr 50g nonfasting GCT <7.8 normal, 7.8-10.2 – 75g OGTT, >10.3 – GDM 75g OGTT: to confirm if positive with 1hr test DM if >5.3/10.6/8.9 at 0,1,2hr
28wk	Repeat CBC / Hg (screen with anemia in T3) often with GDM screening (24-26wk)Re-screen STI/HIV if high risk Rh – : repeat type & screen for alloantibodies before Adm Rh +: repeat type & screen for alloantibodies – not necessary if 2 previous results on file RH – : Rhrogam 300mcg IM
30-32wk	u/s to r/o IUGR in women w/initial wt >90kg or BMI >30
28-36 wk	Repeat HIV, G/C, syphilis testing if at risk
35-37 wk	GBS swab (36wk) – vaginal + rectal (valid for 5 wk), send result to delivery suit unless + GBS bacteriuria during the current pregnancy or prev infant with GBS dz
38+ wk	Consider Cervical exam at prenatal visitOffer sweeping of membranes to prevent posterm getation
41-42 wk	Induction to prevent posterm gestation vs expectant (req fetal monitoring with NST & AFT bi-weekly
Delivery	Rh – : Rhrogam 300mcg IM within 72hr of delivery if Rh+ baby Rubella immunization to nonimmune women BCG for baby, routinely offered to high-risk population, mother be HIV – Intrapartum Prophylaxis: Prev infant with invasive GBS dz + GBS screen in current pregnancy Unknown GBS + <37wkGA or ROM>18hr or intrapartum temp >38oC – use broad-spectrum abx if amnionitis Pen G 5million u IV then 2.5 million u IV Q4h Cefazolin 3g IV then 1g IV q8h (if pen allergy) Clindamycin 900mg IV q8h until delivery (pen anaphylaxis risk) Erythromycin 500mg IV q6h If GBS resistant or susceptibility unknown: Vancomycin 1g IV q12h Prophylaxis not reg: Planned C/S in absence of ROM or labour -ve GBS Cx in current pregnancy (despite prev pregnancy with + GBS) – regardless of intrapartum risk factors
Postpartum	GDM – a 75g OGTT at 6-12 wk pp to screen for persistent DM or impaired glucose tolerance

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5 In pregnant patients:

a) Identify those at high risk (e.g., teens, domestic violence victims, single parents, drug abusers, impoverished women).
b) Refer these high-risk patients to appropriate resources throughout the antepartum and postpartum periods.

OB consult if

1. posible C/S: VBAC, malpresentation, multiple gestation
2. antepartum care: HTN, PTL/PPROM, failure to progress/descend, induction / augmentation if high risk
3. PP care: 3/4 degree tear, retained placenta

Refer to social worker and local mental health unit

 

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6 In at-risk pregnant patients (e.g., women with human immunodeficiency virus infection, intravenous drug users, and diabetic or epileptic women), modify antenatal care appropriately.

Diabetes:

• Insulin for type 1, or type II uncontrolled by diet alone. Oral hypoglycemics (especially glyburide) are controversial
• Diet usually adequate for GDM. Multi-disciplinary approach with diabetes educators, dieticians, and maternity care provider.

HIV:

• Fetus at risk of IUGR, pre-term labor or PROM.
• Rescreen for HIV at 28 – 36 wk GA if high risk
• May deliver vaginally. Combined retroviral for antepartum decrease risk of transmission to <1%.
• Discuss risk of transmission with breast feeding.

Epileptics:

• For planning a pregnancy, switch to the safest effective anti-convulsant at lowest dose(avoid valproic acid). If already pregnant, continue with same anti-convulsant meds.
• Folate supplementation 5mg/d.
• Vit K supplementation in final month with enzyme inducing meds.
• Monitor drug levels.

IVDU:

• Arrange supports, encourage cessation,
• surveilance for HIV/Hep B/C during pregnancy – repeat screening in T3

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References:

• http://sogc.org/guidelines/determination-gestational-age-ultrasound/ 
• TN2014
• http://sogc.org/wp-content/uploads/2013/01/gui197CPG0709r.pdf