The Prenatal Ascertainment Project: Birth Outcomes for

1
The Prenatal Ascertainment Project Birth
Outcomes for Fetuses Diagnosed with Defects
Prenatally in Michigan
Mary Kleyn, MSc, Steve Korzeniewski, MSc, MA,
Joan Ehrhardt, Violanda Grigorescu, MD, MSPH,
Michigan Department of Community Health,
Division of Genomics, Perinatal Health and
Chronic Disease Epidemiology
Abstract Background The Michigan Birth Defects
Program encompasses the Michigan Birth Defects
Registry (MBDR) and Follow-up Program. A
statewide, passive surveillance system, the MBDR
currently does not include information on birth
defects identified in pregnancies ending in
spontaneous abortion before 20 weeks of gestation
or elective termination. The Prenatal
Ascertainment Project is a study intended to
assess the birth outcomes for pregnancies
affected by a prenatally diagnosed birth
defect.Methods From January 2001 through
December 2007, eight hospitals voluntarily
provided case reports for birth defects
identified prenatally the reports included
information on diagnoses, maternal demographics,
and pregnancy outcome. The eight participating
hospitals were located in southeastern, central,
and western Michigan. Results Throughout the
duration of the study, case reports were received
for 1,492 fetuses with prenatally diagnosed birth
defects. Of the 1,492 fetuses, 68 (N1006) were
diagnosed with only one birth defect. About one
in five 19 (N282) had 2 birth defects and 16
(N202) were diagnosed with 3 or more. The
diagnoses of birth defects were missing for two
cases while 66 did not have a recorded
gestational age at time of diagnoses. Nearly 80
(N1140) of 1,426 fetuses with known gestational
age were diagnosed prior to 23 completed weeks of
gestation, the latest gestational age for legal
termination in Michigan. A known birth outcome
was reported for 854 (57) fetuses. Of these,
approximately 40 (N346) were live born, 48
(N407) were terminated, 8 (N69) were
stillborn, and 4 (N32) were miscarried.
Termination was the most common outcome for
fetuses diagnosed with a defect before 20 weeks
gestation and for fetuses with defects of the
nervous system or chromosomal anomalies.
Conclusions The data collected by the Prenatal
Ascertainment Project is not representative of
all birth defects identified prenatally in
Michigan. However, the findings enhanced the
knowledge about birth outcomes for fetuses with
defects and how birth outcomes may affect the
overall rate of birth defects. This study led us
also to believe that specific birth defect
diagnostic groups (nervous system defects and
chromosomal anomalies) may be underestimated
considering the current reporting is only for
live born and stillborn infants. Collecting data
on fetuses with birth defects that are miscarried
prior to 20 weeks gestation or terminated would
provide more accurate estimates of birth defects
rates.
Table 3 Maternal Demographic Characteristics,
Terminated vs. Not Terminated Pregnancies,
Michigan Prenatal Ascertainment Project
Results Throughout the duration of the study,
case reports were received for 1,492 fetuses with
prenatally diagnosed defects. As indicated in
Figure 1, of the 1,492 fetuses, 68 (N1006) were
diagnosed with only one birth defect. About one
in five 19 (N282) had 2 birth defects and 16
(N202) were diagnosed with 3 or more. The
diagnoses of birth defects were missing for two
cases while 66 did not have a recorded
gestational age at time of diagnoses. Nearly 80
(N1140) of 1,426 fetuses with known gestational
age were diagnosed prior to 23 completed weeks of
gestation, the latest gestational age for legal
termination in Michigan Figure 2. Among
fetuses diagnosed with a prenatal defect and a
reported age at diagnosis (N816), approximately
40 (N329) were live born, 48 (N393) were
terminated, 8 (N66) were stillborn, and 3
(N28) were miscarried (Table 1). Termination
was the most common outcome (70) for fetuses
diagnosed with a defect before 20 weeks
gestation. As indicated in Table 2, termination
was also more likely among fetuses diagnosed
prenatally with chromosomal abnormalities and/or
nervous system defects. Table 3 reports
demographic characteristics among women who
either terminated or did not terminate their
pregnancies following prenatal defect diagnosis.
Women of Asian or Arab/Middle Eastern race were
more likely to terminate their pregnancy than not
after prenatal defect diagnosis (Table 3). Women
aged greater than 35 years were significantly
more likely to terminate their pregnancy (63.9).
Single women were less likely (65.6) to
terminate their pregnancy following prenatal
defect diagnosis. Of women who reported
multivitamin use, 84 reported doing so however,
nearly 40 of the data were missing Figure 3.
Demographic N Terminated Not terminated
Race/Ethnicity Race/Ethnicity Race/Ethnicity Race/Ethnicity
Black 110 39.1 60.9
White 613 48.9 51.1
Hispanic 58 32.8 67.2
Native American 4 25.0 75.0
Asian 24 58.3 41.7
Arab/Middle Eastern 14 85.7 14.3
Other 22 68.2 31.8
Missing 19 15.8 84.2
Total 864 47.1 52.9
Age (in years) Age (in years) Age (in years) Age (in years)
lt20 95 21.1 78.9
20-35 569 45.5 54.5
gt35 194 63.9 36.1
Total 858 47.0 53.0
Marital Status Marital Status Marital Status Marital Status
Single 294 34.4 65.6
Married 549 53.7 46.3
Divorced 7 57.1 42.9
Separated 4 50.0 50.0
Widowed 1 0.0 100.0
Missing 9 55.6 44.4
Total 864 47.1 52.9
Background The Michigan Birth Defects Program
encompasses the Michigan Birth Defects Registry
(MBDR) and Follow-up Program. A statewide,
passive surveillance system, the MBDR currently
does not include information on birth defects
identified in pregnancies ending in spontaneous
abortion before 20 weeks of gestation or elective
termination. The Prenatal Ascertainment Project
is a study intended to assess the birth outcomes
for pregnancies affected by a prenatally
diagnosed birth defect.
Note Percentages expressed in the above table
are row percents
Limitations The data collected by the Prenatal
Ascertainment Project is not representative of
all birth defects identified prenatally in
Michigan. Furthermore, the duration of study
participation varied by hospital. Conclusion
Our study findings enhanced our knowledge about
birth outcomes for fetuses with diagnosed defects
and sheds light on how birth outcomes among such
pregnancies may affect the overall rate of birth
defects in Michigan. Public Health
Implications This study led us also to believe
that specific birth defect diagnostic groups
(nervous system defects and chromosomal
anomalies) may be underestimated considering the
current reporting is only for live born and
stillborn infants. Collecting data on fetuses
with birth defects that are miscarried prior to
20 weeks gestation or terminated would provide
more accurate estimates of birth defects rates.
Data source From January 2001 through December
2007, eight hospitals located in southeastern,
central, and western Michigan voluntarily
provided case reports for birth defects
identified prenatally. Case reports included
information on diagnoses, maternal demographics,
and pregnancy outcome. Study design We
conducted a descriptive study utilizing
univariate and bivariate analyses as permitted by
the available data.
Table 1 Gestational Age at Prenatal Defect
Diagnosis by Pregnancy Outcome, Michigan Prenatal
Ascertainment Project
Table 2 Prenatal Defect Type by Pregnancy
Outcome, Michigan Prenatal Ascertainment Project
Birth Defect Category   Live-born Live-born Stillborn Stillborn Miscarriage Miscarriage Termination Termination Total Missing
Birth Defect Category   N N N N N N
Nervous System 77 76.2 7 6.9 2 2.0 115 57.2 101 97
Heart and Circulatory System 68 52.7 14 10.9 2 1.6 45 34.9 129 141
Respiratory System 12 75.0 0 0.0 1 6.3 3 18.8 16 17
Cleft Lip and/or Palate 25 78.1 2 6.3 0 0.0 5 15.6 32 37
Genital/Urinary System 58 50.9 11 9.6 4 3.5 41 36.0 114 87
Musculoskeletal System 108 55.4 13 6.7 7 3.6 67 34.4 195 164
Chromosomal 48 15.6 33 10.7 22 7.2 204 66.4 307 153
Other 22 35.5 11 17.7 1 1.6 28 45.2 62 55
Age at Dx Live-born Live-born Stillborn Stillborn Miscarriage Miscarriage Termination Termination Total
Age at Dx N N N N N
lt20 weeks 73 18.5 22 5.6 25 6.3 274 69.5 394
20-24 weeks 145 49.7 27 9.2 2 0.7 118 40.4 292
gt24 weeks 111 85.4 17 13.1 1 0.8 1 0.8 130
Total 329 40.3 66 8.1 28 3.4 393 48.2 816
Note 54 prenatally diagnosed cases were missing
age at diagnosis