Background

Orofacial clefts includes all cleft lip and cleft palate birth defects [1]. Orofacial clefts occur when a baby’s lip and/or palate do not form properly during early pregnancy. Cleft lip occurs when the lip does not come together during development, separating the lip either on one side (unilateral) or on both sides (bilateral) [2]. Cleft palate occurs when the roof of the mouth fails to join together resulting in an opening in either the front of the palate, the back of the palate, or both [1]. The lip and palate develop separately during pregnancy, therefore, a baby can have either cleft lip, cleft palate, or both cleft lip and cleft palate [2]. Orofacial clefts are one of the most common birth defects in the United States [2, 3]. While the exact cause for most cases of orofacial clefts is unknown. It is believed that a combination of environmental factors, mothers behaviors during early pregnancy (what she eats/drinks and medicine consumed), and genetic factors may contribute to orofacial clefts [1, 2].

Methodology

The Alaska Birth Defects Registry (ABDR) registers birth defects as reported from health care providers using International Classification of Disease (ICD) billing codes. The use of these ICD codes can lead to misclassification of diagnosed conditions. Prior to this report, all prevalence estimates were based on the number of unique children reported to ABDR with an ICD code representing a specified condition regardless of case confirmation status.

The estimates in this report were derived by conducting medical record review and case confirmation of a random sample of cases of the condition reported to ABDR. The confirmation probability from the sample was used to develop informed estimates of the actual diagnosed defect prevalence. See defect prevalence calculation for a complete explanation of the methodology used for generating estimates.

While this report provides the most precise estimates, caution should be used in interpreting prevalence estimates based on conditions with <30 annual reports, as they are potentially vulnerable to large year-to-year variation.

For explanations of table columns see column descriptions.

All Oral Facial Clefts

According to the 2014 annual report released by the National Birth Defects Prevention Network (NBDPN), the prevalence of all orofacial clefts for 29 U.S. States from 2007-2011 was 14.5 per 10,000 live births.[3]

In Alaska, during 2007-2017, the prevalence of all orofacial clefts was 33.8 per 10,000 live births.*
Reports Defects Births Prevalence (95% CI)
Total 39 35.3 10446 33.8 (24.1, 46.6)
Notes: 95% CI = 95% Confidence Interval

Cleft Lip

Cleft Lip Prevalence

According to the 2014 annual report released by the National Birth Defects Prevention Network (NBDPN), the prevalence of cleft lip was for 29 U.S. States from 2007-2011 was 3.1 per 10,000 live births.[3]

In Alaska, during 2007-2017, the prevalence of cleft lip was 4.7 per 10,000 live births.
Reports Defects Births Prevalence (95% CI)
Total 124 57.5 123630 4.7 (3.6, 6.0)
Notes: 95% CI = 95% Confidence Interval

Cleft Lip Trend

Prevalence per 10,000 births of Cleft Lip during 2007-2017 by three-year moving averages, with 95% confidence interval band and Poisson estimated fitted line.

The p-value test for trend detected no significant increase or decrease in the number of live births with cleft lip during 2007-2017. See p-value estimate
Estimate Std. Error t value Pr(>|t|)
0.01761 0.01314 1.34058 0.22193

Reports Defects Births Prevalence (95% CI) Predicted Prevalence†
2007-2009 10.7 5.7 11262.0 5.0 (2.1, 10.8) 4.7
2008-2010 9.7 5.2 11404.3 4.5 (1.8, 9.8) 4.7
2009-2011 9.3 4.9 11404.7 4.3 (1.6, 9.4) 4.8
2010-2012 11.0 5.1 11354.0 4.5 (1.8, 9.8) 4.9
2011-2013 13.3 6.0 11349.0 5.2 (2.3, 11.1) 5.0
2012-2014 14.0 6.2 11334.7 5.5 (2.3, 11.1) 5.1
2013-2015 14.0 6.7 11377.3 5.8 (2.5, 11.5) 5.2
2014-2016 12.0 6.0 11295.0 5.3 (2.1, 10.7) 5.3
2013-2017 10.0 5.1 10979.7 4.6 (1.8, 10.2) 5.4
Notes: Each row is based on three-year moving averages; Prevalence reported per 10,000 live births; 95% CI=95% Confidence Interval

† Estimated rate based on Poisson model

Cleft Lip Regional Distribution

Distribution of cleft lip in Alaska by Public Health Region of maternal residence at the time of birth. A description of regional breakdowns can be found here. Data suppressed for # of reports < 6.

Reports Defects Births Prevalence (95% CI)
Anchorage 36 15.5 50455 3.1 (1.8, 4.9)
Gulf Coast 13 5.3 7725 6.9 (2.9, 15.1)
Interior 21 8.8 22487 3.9 (1.8, 7)
Mat-Su 12 5.1 14937 3.4 (1.5, 7.8)
Northern 10 4.1 8520 4.9 (1.9, 12)
Southeast 8 3.3 7625 4.4 (1.4, 11.5)
Southwest 24 9.7 11881 8.2 (4, 14.4)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Lip Demographics

Some subgroups may be more at risk for having a baby with a cleft lip. This section provides the descriptive epidemiology of specified maternal, birth, and child characteristics identified from the birth certificate.

## `mutate_all()` ignored the following grouping variables:
## Column `grp`
## Use `mutate_at(df, vars(-group_cols()), myoperation)` to silence the message.
Reports Defects Births Prevalence (95% CI)
Sex
  Female 48 20.4 59998 3.4 (2.2, 5.2)
  Male 76 31.5 63632 5.0 (3.4, 6.9)
Birth weight (grams)
  <2500 13 5.3 7231 7.3 (3.0, 16.1)
  2500+ 111 46.7 116215 4.0 (3.0, 5.3)
Maternal age
  12-19 10 4.2 9156 4.6 (1.8, 11.2)
  20-24 44 18.1 32872 5.5 (3.5, 8.7)
  25-29 31 13.2 37743 3.5 (2.0, 5.9)
  30-34 27 11.3 28152 4.0 (2.2, 7.0)
  35-39 - - 12614 3.1 (0.9, 7.0)
  40+ - - 3064 -
Maternal race
  Alaska Native/American Indian 55 22.4 31560 7.1 (4.6, 10.6)
  Asian/Pacific Islander - - 11810 3.6 (1.4, 8.7)
  Black - - 5081 -
  White 54 23.2 73595 3.1 (2.1, 4.7)
Maternal education (years)
  <12 15 6.2 11929 5.2 (2.4, 10.9)
  12 63 25.8 43162 6.0 (3.9, 8.6)
  12+ 45 19.4 65105 3.0 (1.9, 4.6)
Marital status
  Married 63 26.8 78396 3.4 (2.3, 4.9)
  Unmarried 60 24.7 44625 5.5 (3.6, 8.0)
Maternal smoking use
  Reported smoking 29 11.8 16817 7.0 (3.7, 11.7)
  Reported not smoking 91 38.5 104707 3.7 (2.6, 5.0)
Medicaid (mother or child)
  Medicaid 96 39.3 62666 6.3 (4.6, 8.5)
  non-Medicaid 28 12.6 60839 2.1 (1.1, 3.5)
Father on birth certificate
  None 6 2.5 6328 4.0 (1.0, 11.4)
  Present 118 49.4 117302 4.2 (3.2, 5.5)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval


Cleft Palate

Cleft Palate Prevalence

According to the 2014 annual report released by the National Birth Defects Prevention Network (NBDPN), the prevalence of cleft palate for 29 U.S. States from 2007-2011 was 5.9 per 10,000 live births.[3]

In Alaska, during 2007-2017, the prevalence of cleft palate was 13.7 per 10,000 live births.
Reports Defects Births Prevalence (95% CI)
Total 250 169.8 123630 13.7 (11.8, 15.9)
Notes: 95% CI = 95% Confidence Interval

Cleft Palate Trend

Prevalence per 10,000 births of cleft palate during 2007-2017 by three-year moving averages, with 95% confidence interval band and Poisson estimated fitted line.
The p-value test for trend detected a significant increase in the number of live births with cleft palate during 2007-2017. See p-value estimate
Estimate Std. Error t value Pr(>|t|)
0.02167 0.00516 4.19725 0.00405

Reports Defects Births Prevalence (95% CI) Predicted Prevalence†
2007-2009 19.0 14.3 11262.0 12.8 (7.2, 20.5) 12.9
2008-2010 22.0 15.6 11404.3 13.7 (8.0, 21.7) 13.2
2009-2011 22.7 15.6 11404.7 13.7 (8.0, 21.7) 13.5
2010-2012 23.7 15.7 11354.0 13.8 (8.1, 21.7) 13.8
2011-2013 22.0 15.0 11349.0 13.2 (7.6, 21.0) 14.1
2012-2014 23.7 15.9 11334.7 14.0 (8.3, 22.2) 14.4
2013-2015 24.7 17.1 11377.3 15.0 (9.1, 23.6) 14.7
2014-2016 26.3 17.9 11295.0 15.9 (9.7, 24.5) 15.0
2013-2017 24.0 16.4 10979.7 14.9 (9.0, 23.6) 15.4
Notes: Each row is based on three-year moving averages; Prevalence reported per 10,000 live births; 95% CI=95% Confidence Interval

† Estimated rate based on Poisson model

Cleft Palate Regional Distribution

Distribution of cleft palate in Alaska by Public Health Region of maternal residence at the time of birth. A description of regional breakdowns can be found here. Data suppressed for # of reports < 6.

Reports Defects Births Prevalence (95% CI)
Anchorage 89 61.0 50455 12.1 (9.2, 15.3)
Gulf Coast 24 15.2 7725 19.6 (11.8, 32)
Interior 36 25.1 22487 11.2 (7.6, 16.4)
Mat-Su 21 15.0 14937 10.1 (6.1, 16.6)
Northern 27 17.0 8520 20 (12.5, 31.9)
Southeast 14 9.5 7625 12.5 (6.3, 22.4)
Southwest 39 24.5 11881 20.6 (13.6, 30.1)
Notes:Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Palate Demographics

Some subgroups may be more at risk for having a baby with a cleft palate. This section provides the descriptive epidemiology of specified maternal, birth, and child characteristics identified from the birth certificate.

## `mutate_all()` ignored the following grouping variables:
## Column `grp`
## Use `mutate_at(df, vars(-group_cols()), myoperation)` to silence the message.
Reports Defects Births Prevalence (95% CI)
Sex
  Female 118 79.3 59998 13.2 (10.6, 16.4)
  Male 132 88 63632 13.8 (11.1, 16.9)
Birth weight (grams)
  <2500 34 20.6 7231 28.6 (18.0, 42.7)
  2500+ 216 146.6 116215 12.6 (10.7, 14.8)
Maternal age
  12-19 25 16 9156 17.5 (10.8, 28.4)
  20-24 63 42.5 32872 12.9 (9.5, 17.3)
  25-29 76 50.9 37743 13.5 (10.1, 17.5)
  30-34 53 35.9 28152 12.8 (9.0, 17.3)
  35-39 27 17.9 12614 14.2 (8.5, 21.6)
  40+ 6 4 3064 13.2 (5.3, 33.4)
Maternal race
  Alaska Native/American Indian 116 72 31560 22.8 (17.9, 28.4)
  Asian/Pacific Islander 19 13.2 11810 11.2 (6.5, 18.8)
  Black 7 5 5081 9.9 (4.3, 23.0)
  White 106 75.6 73595 10.3 (8.1, 12.8)
Maternal education (years)
  <12 32 20.6 11929 17.2 (10.9, 25.9)
  12 108 70 43162 16.2 (12.8, 20.5)
  12+ 103 72 65105 11.1 (8.8, 13.9)
Marital status
  Married 129 89.5 78396 11.4 (9.2, 14.0)
  Unmarried 120 77.1 44625 17.3 (13.8, 21.6)
Maternal smoking use
  Reported smoking 59 36.8 16817 21.9 (15.5, 29.6)
  Reported not smoking 182 125 104707 11.9 (9.9, 14.1)
Medicaid (mother or child)
  Medicaid 176 112.4 62666 17.9 (14.9, 21.5)
  non-Medicaid 74 54.8 60839 9.0 (6.8, 11.6)
Father on birth certificate
  None 15 9.8 6328 15.5 (7.6, 27.0)
  Present 235 157.5 117302 13.4 (11.4, 15.7)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Lip with Cleft Palate

Cleft Lip with Cleft Palate Prevalence

According to the 2014 annual report released by the National Birth Defects Prevention Network (NBDPN), the prevalence of cleft lip with cleft palate for 29 U.S. States from 2007-2011 was 5.6 per 10,000 live births.[3]

In Alaska, during 2007-2017, the prevalence of cleft lip with cleft palate was 13.8 per 10,000 live births.
Reports Defects Births Prevalence (95% CI)
Total 117 170.0 123630 13.8 (11.8, 15.9)
Notes: 95% CI = 95% Confidence Interval

Cleft Lip with Cleft Palate Trend

Prevalence per 10,000 births of cleft lip with cleft palate during 2007-2017 by three-year moving averages, with 95% confidence interval band and Poisson estimated fitted line.

The p-value test for trend detected no significant trend in the number of live births with cleft lip with cleft palate during 2007-2017. See p-value estimate
Estimate Std. Error t value Pr(>|t|)
0.04747 0.01485 3.19571 0.01516

Reports Defects Births Prevalence (95% CI) Predicted Prevalence†
2007-2009 6.7 13.7 11262.0 12.2 (6.8, 19.7) 11.8
2008-2010 7.3 13.7 11404.3 12.0 (6.7, 19.5) 12.4
2009-2011 7.3 13.3 11404.7 11.6 (6.5, 19.1) 13.0
2010-2012 8.3 14.1 11354.0 12.4 (6.9, 19.9) 13.6
2011-2013 12.3 16.9 11349.0 14.8 (8.7, 22.8) 14.2
2012-2014 15.7 19.0 11334.7 16.7 (10.3, 25.4) 14.9
2013-2015 17.3 20.7 11377.3 18.2 (11.7, 27.5) 15.7
2014-2016 14.0 18.6 11295.0 16.4 (10.4, 25.5) 16.4
2013-2017 12.0 16.0 10979.7 14.6 (8.8, 23.2) 17.2
Notes: Each row is based on three-year moving averages; Prevalence reported per 10,000 live births; 95% CI=95% Confidence Interval

† Estimated rate based on Poisson model

Cleft Lip with Cleft Palate Regional Distribution

Distribution of cleft lip with cleft palate in Alaska by Public Health Region of maternal residence at the time of birth. A description of regional breakdowns can found here. Data suppressed for # of reports < 6.
Reports Defects Births Prevalence (95% CI)
Anchorage 36 24.4 50455 4.8 (3.2, 7.1)
Gulf Coast 13 8.7 7725 11.2 (5.3, 20.4)
Interior 23 15.4 22487 6.9 (4.1, 11)
Mat-Su 9 6.1 14937 4.1 (1.9, 8.7)
Northern 12 8.0 8520 9.4 (4.8, 18.5)
Southeast 6 4.0 7625 5.3 (2.1, 13.4)
Southwest 18 12.0 11881 10.1 (5.8, 17.6)
Notes:Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Cleft Lip with Cleft Palate Demographics

Some subgroups may be more at risk for having a baby with a cleft lip with cleft palate. This section provides the descriptive epidemiology of specified maternal, birth, and child characteristics identified from the birth certificate.

## `mutate_all()` ignored the following grouping variables:
## Column `grp`
## Use `mutate_at(df, vars(-group_cols()), myoperation)` to silence the message.
Reports Defects Births Prevalence (95% CI)
Sex
  Female 46 31.1 59998 5.2 (3.6, 7.3)
  Male 71 47.6 63632 7.5 (5.6, 9.8)
Birth weight (grams)
  <2500 20 13.3 7231 18.4 (10.6, 30.7)
  2500+ 97 65.4 116215 5.6 (4.4, 7.1)
Maternal age
  12-19 - - 9156 7.3 (3.1, 14.3)
  20-24 35 23.5 32872 7.1 (4.7, 10.5)
  25-29 27 18.3 37743 4.8 (3.0, 7.5)
  30-34 25 16.8 28152 6.0 (3.5, 9.2)
  35-39 16 10.7 12614 8.5 (4.3, 14.6)
  40+ - - 3064 -
Maternal race
  Alaska Native/American Indian 50 33.4 31560 10.6 (7.5, 14.7)
  Asian/Pacific Islander - - 11810 6.3 (2.9, 12.2)
  Black - - 5081 -
  White 52 35.2 73595 4.8 (3.4, 6.6)
Maternal education (years)
  <12 17 11.4 11929 9.5 (5.2, 16.5)
  12 50 33.5 43162 7.8 (5.5, 10.7)
  12+ 46 31.1 65105 4.8 (3.4, 6.8)
Marital status
  Married 66 44.5 78396 5.7 (4.2, 7.5)
  Unmarried 50 33.5 44625 7.5 (5.3, 10.4)
Maternal smoking use
  Reported smoking 22 14.7 16817 8.8 (5.0, 14.0)
  Reported not smoking 90 60.6 104707 5.8 (4.5, 7.4)
Medicaid (mother or child)
  Medicaid 84 56.2 62666 9.0 (6.9, 11.6)
  non-Medicaid 33 22.5 60839 3.7 (2.4, 5.5)
Father on birth certificate
  None - - 6328 -
  Present - - 117302 6.4 (5.1, 8.0)
Notes: Prevalence reported per 10,000 live births; Data suppressed for # of reports < 6; 95% CI = 95% Confidence Interval

Technical notes

Column descriptions

# Reports: Unless otherwise noted, the number of unique reports of the defect received by ABDR during the specified birth year(s). Each report represents a unique child with the specified defect.

# Defects: The estimated true number of reports that are diagnosed defects based on medical record review and case confirmation.

# Births: The number of live births among Alaskan residents that occurred in Alaska during the specified birth year(s).

Prevalence (95% CI): The estimated diagnosed prevalence of the condition and corresponding 95% Confidence Interval. (For information on how the defect prevalence was estimated see below).

Defect prevalence calculation

The estimated defect prevalence was calculated using a Bayesian approach based on the reported prevalence, PPV and 1-NPV (see formula below).

Through medical records review and case confirmation of a random sample of reported cases, the defect prevalence is calculated as:

\[PPV (Positive Predictive Value) = p(defect|report)\] \[NPV (Negative Predictive Value) = p(\overline{defect}|\overline{report})\]

\[p(defect) \approx [p(report)\cdot PPV]+[p(\overline{report})\cdot (1-NPV)]\]

For cleft conditions, many cases were determined to be a different cleft defect than what was reported. Therefore, an additional intra-conditional probability was calculated and applied to the prevalence estimates. This probability accounts for the misclassified cleft conditions that were reported. In addition, a number of individuals were reported for more than one, or all three possible cleft conditions. For these individuals a separate PPV and NPV was calculated and applied.

Defect prevalence estimates are a more accurate estimation of the actual diagnosed prevalance of birth defects compared to the reported prevalance estimates in Alaska. ABDR obtains reports from medical providers using International Classification of Disease (ICD) codes that are extracted from individual systems which when aggregated may not reflect true diagnostics. Caution should be used when interpreting and comparing the reported prevalence estimates with national estimates.

See Data analysis methods for more information.

P-value estimate

To evaluate the trend over time and account for under/over-dispersion we constructed a quasi-Poisson regression model. This model assumes the variance is a linear function of the mean, and models the estimated number of annual defects by year with a natural log (ln) offset of the annual births. P-values < 0.05 are considered significant, which indicates that the predicted slope is significantly different from a slope of zero.

Data suppression

For region and demographic data tables, values are suppressed based on the number of reports received during the observation period. Counts less than 6 are suppressed (as indicated by ‘-’ in the table). For regions or demographics with only one cell count suppressed a second is suppressed to eliminate the ability to back-calculate the estimate.

References

[1] Facts about Cleft Lip and Cleft Palate | CDC. (2017). Centers for Disease Control and Prevention. Retrieved 22 March 2019, from https://www.cdc.gov/ncbddd/birthdefects/cleftlip.html

[2] Introduction to Cleft & Craniofacial Conditions - ACPA Family Services. (2019). Cleftline.org. Retrieved 22 March 2019, from https://cleftline.org/family-resources/introduction-to-cleft-craniofacial-conditions/

[3] Mai, C. T., Cassell, C. H., Meyer, R. E., Isenburg, J., Canfield, M. A., Rickard, R., … & Cho, S. J. (2014). Birth defects data from population-based birth defects surveillance programs in the United States, 2007 to 2011: Highlighting orofacial clefts. Birth Defects Research Part A: Clinical and Molecular Teratology, 100(11), 895-904.

Authorship

Maternal and Child Health (MCH) senior epidemiologist Dr. Jared Parrish, PhD conceived of the presented analysis. Alaska Birth Defects Registry program manager and epidemiologist Chris Barnett, MS MPH and Dr. Jared Parrish, PhD developed the theory and performed the computations. Research analysts Monica Mills and Jordyn Lord managed data collection and storage. All authors discussed the results and contributed to the final report.

Suggested Citation

State of Alaska Department of Health and Social Services, Division of Public Health, Section of Women’s, Children’s, and Family Health. Alaska Birth Defects Registry Condition Report: Cleft Conditions, Alaska, 2007-2017. Updated June 23, 2021. Available at: http://rpubs.com/AK_ABDR/cleft_Conds.

Contact

Alaska Birth Defects Registry (ABDR)
3601 C Street, Suite 358
Anchorage, AK 99503
(907) 269-3400 phone
(907) 754-3529 fax

Updated: June 23, 2021
Code source: R:\ABDR\Analysis_New\ABDR_CASECONF\cond_reports\Published_reports\cleft_conds07_17.Rmd