Congenital Hypothyroid Screening among Low Birth Weight InfantsPresentation Transcript
Congenital Hypothyroid Screening among Low Birth Weight Infants, Michigan, 2005-2007 Steven J. Korzeniewski, MA, MSc, Maternal & Child Health Epidemiology Section Manager Violanda Grigorescu, MD, MSPH, William I. Young, Ph.D. Bureau of Epidemiology, Division of Genomics, Perinatal Health and Chronic Disease Epidemiology
Number of Infants Screened by Birth Weight, Michigan, 2007 - 100 121,080 91.92 111,291 >=2500g 6,995 8.08 9,789 3.65 4,422 2200-2499g 2,573 4.43 5,367 1.28 1,554 2000-2199g 1,019 3.15 3,813 0.84 1,019 1800-1999g - 2.31 2,794 2.31 2,794 < 1800g Estimated Number of Infants Added to the NICU Protocol (Cumulative) Cumulative % Cumulative Frequency % Frequency Birth Weight
NICU Protocol Evaluation Conclusions
NICU protocol inclusion criteria currently does not consider gestational age.
GA is thought to be a better indicator of maturity than BW; however, concerns about data quality have led the latter to be used.
Adding very preterm and below (GA < 32 wks) infants would add 215 infants based on 2007 data.
We are evaluating the impact of:
increasing the birthweight inclusion criterion to ~2300g,
adding very preterm and below (GA < 32 wks) infants, and
eliminating 2 nd screens for infants born weighing less than ~1,000g-1,500g.
Clinical Laboratory Standards Institute (CLSI) has a subcommittee working on a proposed standard for NBS of SCBU/NICU infants
Who are we detecting?
Is the 10 fold increase in risk of CH among infants < 1800g compared to those >= 1800g real ?
Standard of care is to follow-up CH cases until at least age three years (AAP Guidelines)
Diagnostic verification recommended (permanent vs. transient CH)
Thyroid function trial
Rate and outcome of diagnostic verification unknown
CH Three Year Follow-up of ‘ Borderline ’ Cases
‘ Borderline’ was initially considered as having pre-treatment serum TSH values below the 15 Th percentile.
We recently expanded our criteria to include cases below the 25th percentile and now plan to follow all cases to age 3 years.
Survey developed and pilot tested in collaboration with PEAC endocrinologists
Medical management data maintained by NBS Follow-up program used to locate cases’ physicians.
LTFU mitigated by use of MCIR and phone based survey
Demographics of Michigan CH Cases Detected by NBS Classified by Pre-Treatment Serum TSH/FT4 Values, 9/2003-9/2007 25.8 58 53.1 3001 38.5 30.43% 70 FT4 >=.9, TSH <40 55.6 66.7 50 2461 34.1 3.91% 9 FT4 < .9, TSH < 40 18.2 33.3 61.5 3254 38 20.87% 48 FT4 >=.9, TSH >=40 19.6 39.2 79.1 3156 37.9 44.78% 103 FT4 < .9, TSH >=40 NICU (%) Male (%) White (%) Mean BW Mean GA % N Classification
Preliminary Findings of the CH Three year follow-up study
Preliminary findings indicate:
47% (9/19) of cases with completed diagnostic re-evaluation to date appear not to have permanent CH.
A surprising number of patients (families) have stopped treatment of their own accord (7/23 with completed follow-up); this phenomenon requires further study.
One case (family) described miscommunication with health care provider and lack of follow-up as impetus to treatment cessation.
While all patients who stopped treatment on their own are thought to be transient CH (confirmation of transient CH is pending TSH value receipt- two patients have provided such confirmation to date), only 2/12 cases evaluated by an endocrinologist/hcp are considered transient.
This finding may have implications for the method of diagnostic re-evaluation.
Some cases were confirmed based on increasing treatment dosage at approximately 6 months of age; should this preclude three year thyroid challenge?
Questions remain about process and outcome of three year CH re-evaluation.
Newborn screening at 24-36hrs of life does not detect children with CH having late rising TSH
NICU screening protocols increase CH detection significantly
It is possible that some moderately LBW children having CH and late rising TSH remain undetected.
NICU algorithm inclusion criteria require further evaluation
Gestational age should likely be considered
It is possible that many borderline cases, which likely includes children with CH detected by the 2 nd or 3 rd screen, are transient
Such cases are more likely to be male, LBW, NICU births, and/or racial minorities
Three year follow-up is of critical importance to differentiate transient from permanent CH, particularly in states conducting routine second screens or having NICU/LBW protocols.
Bill Young, Manger, Newborn Screening Follow-up Program
Violanda Grigorescu, Director, Division of Genomics, Perinatal Health & Chronic Disease Epidemiology
Newborn Screening Follow-up Staff
Pediatric Endocrine Advisory Committee
Thank You [email_address] http://www.michigan.gov/mchepi