september 28 30, 2018 - cpb-us-w2.wpmucdn.com · macrosomia‐abramowicz fetal growth patterns lga...

Course Director

September 28-30, 2018

Macrosomia ‐Abramowicz

Jacques S. Abramowicz, MD, FACOG, FAIUM

University of Chicago

Going the Other Way: When

Babies Get Too Big

Disclosure

I have no conflict of interest with respect to any of the material presented in this lecture.

I am an author for UpToDateI am a consultant for Samsung

I will not discuss off-label or unapproved uses of drugs or devices.

Objectives

At the end of the presentation the participants will be able to: 1.Define fetal macrosomia;2.List maternal and fetal complications of macrosomia;3.Describe methods to diagnose macrosomia.4.Outline management strategies


Definition (1)

Macrosomia: growth beyond a specific threshold, regardless of gestational age.

In developed countries, the most commonly used threshold is weight above 4500 g (9 lb 15 oz)

Weight above 4000 g (8 lb 13 oz) or 10 lb (4536 g) are also commonly used

A grading system has also been suggested: grade 1 for infants 4000 to 4499 g, grade 2 for 4500 to 4999 g, and grade 3 for over 5000 g

These thresholds are not based upon population statistics, where normal weight is typically defined as between the 10th and 90th percentile for gestational age (assuming a normal population distribution).

Macrosomia refers to the newborn. Fetal macrosomia can only be suspected

Definition (2)

95th percentile as threshold for macrosomia as it corresponds to 1.90 SD >mean and defines 90% of the population as normal weight.

97.75th percentile, which corresponds to 1.96 SD>mean and defines 95% of the population as normal weight.

The use of contemporary country‐specific percentile tables is advisable

Newborn weights have increased over the past few decade, making older tables (Lubchenko) obsolete

Some older tables excluded, by choice, African‐American, Asian, and Native American infants

Racial and ethnic differences influence birth weight, thus should be considered when interpreting EFW and BW

Macrosomia-prevalence

Worldwide prevalence of birth of infants≥4000 g: ~ 9 percent (0.5-14.9%)≥5000 g: ~0.1 percent

In the United States≥4000 g: 8%>4500 g: 1.1%


Fetal growth patterns

LGAIntrinsic

(earlier, constitutional, symmetric)

Extrinsic(later, metabolic, asymmetric)

Etiology

Maternal Risk factors for having a macrosomic infant*

Maternal obesity (prepregnancy BMI>30kg/m2)

Multiparity

Advanced maternal age

Maternal diabetes

Postterm pregnancy

Male infant

Previous macrosomic infant

Excessive gestational or interpregnancy weight gain

Hispanic or African-American ethnicity

Maternal birth weight over 4000 grams

*Abramowicz JS, Ahn JT: Fetal Macrosomia. UpToDate, 2017


Etiology

Common mechanism

Etiology-Genetic syndromes

Pallister-Killian (anomalous extra isochromosome 12p)Beckwith-Wiedemann (Omphalocele-Visceromegaly-Macroglossia Syndrome)Sotos (aka cerebral gigantism. Most cases result from new mutations of NSD1 gene)Perlman (aka renal hamartomas, nephroblastomatosis and fetal gigantism. DIS3L2 gene found on chromosome 2 at 2q37.2)Simpson-Golabi-Behmel (X-linked dysplasia gigantism syndrome [DGSX]). Costello (aka faciocutaneoskeletal syndrome. Autosomal dominant. Mutations in the HRAS gene)Weaver (Sporadic. Mutations in the EZH2 gene on chromosome 7q36)Macrocephaly Cutis Marmorata Telangiectasia Congenita (M-CMTC)


Conclusions

The current study provides evidence that gravidas with high level of ferritin may be prone to GDM. Besides, high level of ferritin may be an independent risk factor for macrosomia outcome. Therefore, the negative effect of iron supplementation in non‐anemia pregnant women may be noteworthy.

2018

Risks

The risk of adverse outcome increases along a continuum based on the degree of macrosomia (eg, 4000-4499 g, 4500-4999 g, ≥5000 g)

Maternal risks

Protracted or arrested labor

Operative vaginal delivery

Cesarean delivery

Genital tract lacerations (vaginal, third‐degree and fourth‐degree perineal)

Postpartum hemorrhage

Uterine rupture


Fetal/Neonatal risks

Shoulder dystocia leading to birth trauma (brachial plexus injury, fracture) or asphyxia.

Hypoglycemia

Respiratory problems

Polycythemia

Minor congenital anomalies

Increased frequency of admission and prolonged admission (greater than three days) to a neonatal intensive care unit

Childhood and beyond

Obesity

Impaired glucose tolerance

Metabolic syndrome (increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels)

Cardiac remodeling (increase in aorta

intima‐media thickness and left ventricular

mass)

Macrosomia-Diagnostic challenges

Errors, regardless of methodThe precision of ultrasound measurements declines as fetal weight increases.Inaccuracies of fetal weight estimation at the upper extremeMaternal overweight/obesity


Diagnosis (1)-Non-ultrasound methods

Maternal estimation: in parous women, as or more accurate than clinical or sonographic estimates* Physical examination: fundal height, Leopold maneuvers (affected by maternal habitus, fetal position, amount of amniotic fluid, examiner's experience): both combined: sensitivity of 10-43% and PPV 28-53% for detecting macrosomia

*Harlev A, Walfisch A, Bar-David J, et al. Maternal estimation of fetal weight as a complementary method of fetal weight assessment: a prospective clinical trial. J Reprod Med 2006; 51:515.

Diagnosis

Method Sensitivity (%) Specificity (%) PPV (%) NPV (%)

Maternal estimate: parous women estimate of weight >4000 g*

56 94 77 86

Clinician's estimate of weight >4000 g#

10 to 43 99.0 to 99.8 28 to 53 -

*Chauhan SP, Sullivan CA, Lutton TC, et al. Parous patients' estimate of birth weight in postterm pregnancy. J Perinatol 1995; 15:192.#Chauhan SP, Hendrix NW, Magann EF, et al. Limitations of clinical and sonographic estimates of birth weight: experience with 1034 parturients. Obstet Gynecol 1998; 91:72.

Diagnosis (1)-Non-ultrasound methods

MRI: meta-analysis of studies comparing MRI vs 2D us for predicting birth weight >4000 g or >90th percentile. MRI for EFW had higher sensitivity (93 vs 56%), but MRI EFW not significantly more sensitive than 2D us for AC>35 cm (93 versus 80 percent)+

+Malin GL, Bugg GJ, Takwoingi Y, et al. Antenatal magnetic resonance imaging versus ultrasound for predicting neonatal macrosomia: a systematic review and meta-analysis. BJOG 2016; 123:77.


Diagnosis-Ultrasound

EFW by combination of biometric parameters (BPD, HC, AC, FL)Serial measurementsAC aloneSoft tissuesFetal volumeNeural networks


Chauhan SP, Grobman WA, Gherman RA, et al. Suspicion and treatment of the macrosomic fetus: a review. Am J Obstet Gynecol 2005; 193:332.

Fetal weight cannot be measured directlyHence, EFW is calculated by integrating biometric measurements into a formulaThe fetus is an irregular, three-dimensional structure of varying densityThus, the ability of any formula to predict fetal density or weight is limited.Available formulas perform better for normal sized fetuses than for macrosomic ones.

Estimated Fetal Weight (EFW)



Review of 14 studies on the sonographic detection of macrosomia (≥4000) in general obstetrical populationsSensitivity: 12-75%Specificity: 68-99%Post-test probability after a positive test: 17-79%Results for populations with a high prevalence of macrosomia were at the upper end of these ranges


AC is the most important parameter for assessment of risk of macrosomiaAC of 35 to 38 cm alone is predictive of macrosomiaAC >90th percentile two to three weeks ahead of GA may be an early marker for development of macrosomia despite normal EFW. Assessment of an enlarged AC on ultrasound should prompt fetal re-evaluation in three to four weeks, especially in patients with diabetes. Predictions for absence or presence of macrosomia can generally be made after two successive scans that show an increased AC. If the AC remains <90th percentile, then performing more ultrasound examinations does not increase predictive value

Rosati P, Arduini M, Giri C, Guariglia L. Ultrasonographic weight estimation in large for gestational age fetuses: a comparison of 17 sonographic formulas and four models algorithms. J Matern Fetal Neonatal Med 2010; 23:675.


Serial measurements: taken over time to create an individual growth curve specific to an individual fetus. Possible to extrapolate from multiple points to predict birth weight


Diagnosis-Ultrasound-Soft tissues

Majority of sonographic EFW formulas do not take body composition into accountBody composition can vary greatly, hence,significant variation in BW can occur among fetuses with similar biometric parametersUltrasound measurement of subcutaneous fat may improve assessment of normal versus accelerated growthBody fat= 14% of BW in neonates, but accounts for 46% of BW varianceFat is very sensitive to abnormal “nutritional” conditions associated with reduced or accelerated growth.

Diagnosis-Ultrasound-Soft tissues

Subcutaneous fat has been measured at the: abdominal wall thigh Midhumerusshoulder peribuccal area

Report of 3 studies, with 287 fetuses: high degree of accuracy in predicting macrosomia, based on measurements of the abdominal or thigh fetal soft tissue, with a pooled detection rate of 80%*

*Maruotti GM, Saccone G, Martinelli P. Third trimester ultrasound soft-tissue measurements accurately predicts macrosomia. J Matern Fetal Neonatal Med 2016;1-5

Observations:1.Babies born to diabetic mothers have big cheeks2.Difference between constitutional LGA and LGA of diabetic

mothers


Cheek-to-cheek diameter (CCD)

Bichat fat pads

Abramowicz JS, Sherer DM, Bar-Tov E, Woods JR Jr.:The cheek-to-cheek diameter in the ultrasonographic assessment of fetal growth. Am J Obstet Gynecol. 1991;165:846-52

Abramowicz JS, Sherer DM, Woods JR Jr.:Ultrasonographic measurement of cheek-to-cheek diameter in fetal growth disturbances. Am J Obstet Gynecol. 1993 Aug;169(2 Pt 1):405-8.

Abramowicz JS, Robischon K, Cox C.: Incorporating sonographic cheek-to-cheek diameter, biparietal diameter and abdominal circumference improves weight estimation in the macrosomic fetus. Ultrasound Obstet Gynecol. 1997 ;9:409-13

Abramowicz JS, Rana S, Abramowicz S.:Fetal cheek-to-cheek diameter in the prediction of mode of delivery. Am J Obstet Gynecol. 2005 ;192:1205-11.


Diagnosis-Ultrasound-Fetal volume

Best approach for predicting macrosomia:combination of 3D volumetric measurements

Volume of upper arms thigh abdomen

with two-dimensional (2D) measurements (formula = -1478.557 + 7.242 X thigh vol +13.309 X upper arm vol + 852.998 X log10 AC vol + 0.526 X BPD3)With combined measurements, mean absolute percentage of error = 6.5% vs 10 to 15% with 2D ultrasound alone.

Schild RL, Fimmers R, Hansmann M. Fetal weight estimation by three-dimensional ultrasound. Ultrasound Obstet Gynecol 2000; 16:445.

Objective: We investigated the diagnostic value of first-trimester adipokines and placental markers in predicting macrosomia.

Methods: 328 women recruited between 11th-13th week of pregnancy; 26 women who gave birth to macrosomicbabies and 34 women who gave birth to normal weight neonates. Evaluation of 1st trimester serum levels of pregnancy associated plasma protein-A, free β-human chorionic gonadotropin, placental growth factor (PIGF), and selected adipokines.

Results: The mothers of macrosomic infants had higher PIGF (p = .049) and irisin concentrations (p = .00003), and lower fetuin-A levels (p = .0002) than had the mothers of normal weight babies. Newborn’s weight correlated positively with maternal irisin (R = 0.454, p = .0003) and negatively with fetuin-A concentrations (R = −0.497, p = .00005). Multiple regression analysis showed that only serum irisin concentration was a significant predictor of birth weight (β = 0.329, p = .03), explaining 14% of its variability. The sensitivity and the specificity of irisin concentration in predicting macrosomia were 0.769 and 0.794, respectively (AUC = 0.818 [95%CI: 0.708–0.928], p = .00001) with a proposed cut-off value of 1725.4 ng/ml.

Conclusions: Our results suggest that mother’s irisin may be an early biomarker of macrosomia.

Management


Pietryga M, Brazer J, Wender-Ozegowska E, Dubiel M, Gudmundsson S (2006). Placental Doppler velocimetry in gestational diabetes mellitus. J Perinatol Med, 34: 108-110

Macrosomia-Fetal Surveillance: is Doppler of value?

Both observational data and randomized control data have failed to show any consistent association between maternal diabetes and abnormal umbilical artery Doppler indices. Current evidence supports the use of umbilical artery Doppler only in those patients with diabetes who have pregnancies complicated by hypertensive diseases, fetal growth restriction, or vasculopathy.Umbilical Doppler studies cannot be recommended as a routine screening for fetal surveillance especially in patients without pre-existing diabetes mellitus

Macrosomia-Fetal Surveillance: is Doppler of value?

Retrospective cohort study of 1281 women with diabetes mellitusCPR in non-anomalous singleton fetuses, measured between 34+0 and 36+6 weeks gestationComparison between types of DM treatment groups and correlation with intrapartum and perinatal outcomes.CONCLUSIONS: Regardless of the type of DM, low CPR associated with poorer neonatal outcomes. Women with T1DM had highest mean UA PI and lowest mean CPR despite no difference in the mean MCA PI between the three groups.

Gibbons A1, Flatley C2, Kumar S3.: The fetal cerebro-placental ratio in diabetic pregnancies is influenced more by the umbilical artery rather than middle cerebral artery pulsatility index. Eur J Obstet Gynecol Reprod Biol. 2017 Feb 3;211:56-61.

Management

To cut or not to cut? That is the question


Management

High risk for shoulder dystocia and brachial plexus injury:Estimated fetal weight >5000 grams in women without diabetes or >4500 grams in women with diabetesPrior shoulder dystocia, especially with a severe neonatal injuryMidpelvic operative vaginal delivery of a fetus with estimated weight >4000 gProlonged second stage or arrest of descent in the second stage and estimated fetal weight >4500 grams

Cesarean delivery in these scenarios is a reasonable optionACOG Committee on Practice Bulletins—Obstetrics. Practice Bulletin No. 173: Fetal Macrosomia. Obstet Gynecol 2016; 128:e195.

Boulvain M, Senat MV, Perrotin F, Winer N et al.: Induction of labour versus expectant management for large-for-date fetuses: a randomised controlled trial. Lancet. 2015 27;385(9987):2600-5.

Study underpowered to detect difference in brachial plexus injury (none occurred in either group)

.

Early induction of labor?

822 women with estimated fetal weight > 95th percentile at termRandomized to induction versus expectant managementInduction of labor associated with reduced risk of shoulder dystocia and associated morbidity,Induction of labour does not increase the risk of caesarean delivery and improves the likelihood of spontaneous vaginal delivery

Boulvain 1, Irion O, Dowswell T, Thornton JG. Induction of labour at or near term for suspected fetal macrosomia.Cochrane Database Syst Rev. 2016 May 22;(5):CD000938.

Induction of labour for suspected fetal macrosomia has not been shown to alter the risk of brachial plexus injury, but power of the included studies to show a difference for such a rare event is limited.

Antenatal estimates of fetal weight are often inaccurate so many women may be worried unnecessarily, and many inductions may not be needed.

Nevertheless, induction of labour for suspected fetal macrosomia results in a lower mean birthweight, and fewer birth fractures and shoulder dystocia


Boulvain 1, Irion O, Dowswell T, Thornton JG. Induction of labour at or near term for suspected fetal macrosomia.Cochrane Database Syst Rev. 2016 May 22;(5):CD000938.

Unexpected observation in the induction group: increased perineal damage

Induction of labour does not appear to alter the rate of caesarean delivery or instrumental delivery,

To prevent one fracture it would be necessary to induce labour in 60 women

Some parents and doctors may feel the evidence already justifies induction, others may justifiably disagree.

Management

Chauhan SP, Grobman WA, Gherman RA, et al. Suspicion and treatment of the macrosomic fetus: a review. Am J Obstet Gynecol. 2005;193:332.

Jacques, ca. 1949Forceps delivery, 4000gm

Thank you

september 28 30, 2018 - cpb-us-w2.wpmucdn.com · macrosomia‐abramowicz fetal growth patterns lga...

Documents