Maternal and Infant Characteristics Among Women with Confirmed or Presumed Cases of Coronavirus Disease (COVID-19) During Pregnancy

Limited information is available on the impact of the COVID-19 pandemic on pregnant women and their newborns. While national data were not available as of August 2021, 14 states vital records offices and the District of Columbia were routinely collecting information on confirmed or presumed COVID-19 cases among pregnant women who then gave birth and reporting this information to the National Center for Health Statistics (NCHS). The table below presents data for this select area on characteristics of women with COVID-19 at any time during pregnancy, and their newborns. These data are based on cases of COVID-19 reported to NCHS and linked to the standard birth record, allowing for an analysis of birth-related data by maternal COVID-19 status. Any additional jurisdictions that begin reporting maternal COVID-19 cases to NCHS will be included in future updates. While these data are not representative of all births in the United States, they are currently the only multi-state birth certificate-based data available. Of note, not all of the 15 reporting areas provided information for the total reporting period (April 2020–August 2021). The information provided is based on 26.8% of all births during the reporting period and the characteristics of the mothers and their newborns reflect the jurisdictions reporting COVID status. States also differed in how information on COVID-19 status was obtained and reported to NCHS. See Technical Notes for more information.

Table 1. Presumed or confirmed cases of maternal COVID-19 during pregnancy, by selected maternal and infant characteristics and by race and Hispanic origin of the mother: 14 states and the District of Columbia, April 2020-August 2021
Number
Total 44,409 1,454,324 19,740 705,688 6,651 170,983 12,749 364,462
Percent distribution
COVID-19 case percent distribution 100.0 44.5 15.0 28.7
Non-COVID-19 case percent distribution5 100.0 48.5 11.8 25.1
Maternal characteristics
Age of mother
Total5 100.1 100.0 99.9 100.0 99.9 100.1 100.1 100.0
Under 20 5.4 4.2 3.9 3.2 6.7 6.6 7.1 5.7
20-24 21.4 18.1 19.5 16.7 25.3 23.4 23.5 21.3
25-29 29.8 27.8 30.7 28.3 31.2 28.9 29.3 29.3
30-34 26.7 29.8 29.8 32.0 23.0 24.6 23.0 25.4
35-39 13.6 16.3 13.5 16.4 10.9 13.1 13.4 14.4
40 or more 3.2 3.8 2.5 3.4 2.8 3.5 3.8 3.9
Educational attainment
Total5,6 100.0 100.0 100.1 100.0 99.9 100.0 100.0 100.0
Less than High School 15.4 11.3 7.0 6.7 11.4 11.1 32.2 22.6
High School graduate or GED 30.0 26.7 25.1 22.8 39.8 36.6 33.8 33.2
Some college 20.6 19.8 20.0 18.6 25.6 25.3 19.2 21.6
Associate degree 8.0 8.0 10.4 9.1 7.4 7.5 4.9 6.7
Bachelor's degree and higher 26.0 34.2 37.6 42.8 15.7 19.5 9.9 15.9
Percentage
Source of payment - Medicaid 48.8 41.2 32.8 30.3 66.8 62.4 65.9 57.7
ICU admission 0.5 0.2 0.3 0.1 0.7 0.2 0.7 0.1
Infant characteristics
Total preterm7 11.67 10.02 10.29 9.32 15.84 14.49 11.32 9.34
   34-36 weeks 8.59 7.35 7.77 7.02 10.94 9.62 8.48 6.98
   Less than 34 weeks 3.08 2.68 2.52 2.31 4.90 4.86 2.85 2.36
Low birthweight8 8.82 7.99 7.27 6.90 14.54 14.20 7.97 6.89
   Very low birthweight9 1.52 1.31 1.18 1.04 2.78 2.86 1.26 1.12
NICU admission 10.0 8.8 9.1 8.6 13.3 12.4 9.4 7.6
Infant living10 99.8 99.8 99.8 99.8 99.5 99.6 99.8 99.8
Table

 

 

Maternal or infant characteristic

Total1 Non Hispanic White2 Non-Hispanic Black2 Hispanic3
Yes
COVID-194
No
COVID-19
Yes
COVID-194
No
COVID-19
Yes
COVID-194
No
COVID-19
Yes
COVID-194
No
COVID-19

1 Includes births to race and origin groups not shown separately, such as non-Hispanic American Indian or Alaska Native, non-Hispanic Native Hawaiian or Other Pacific Islander, non-Hispanic multiple race and Hispanic origin not stated.
2 Race and Hispanic origin are reported separately on birth certificates; persons of Hispanic origin may be of any race. In this table, non-Hispanic women are classified by race. Race categories are consistent with the 1997 Office of Management and Budget standards; see reference 1. Single-race is defined as only one race reported on the birth certificate.
3 Includes all persons of Hispanic origin of any race; see reference 1.
4 Confirmed or presumed COVID-19 during pregnancy. Confirmed cases only are included for California, Maryland, Ohio, North Dakota, and Tennessee.
5 May not add to 100.0 percent due to rounding error.
6 Includes women who may not have had time to complete their education.
7 Gestational age in completed weeks; based on the obstetric estimate of gestation.
8 Less than 2,500 grams
9 Less than 1,500 grams
10 Infant living at time of discharge or transfer from hospital.

NOTES: Reporting area includes Alabama, Alaska, Arkansas, California, District of Columbia, Idaho, Maine, Maryland, New Hampshire, North Dakota, Ohio, Oklahoma, Oregon, Tennessee, and West Virginia. See Technical notes for numbers and distributions of cases by state and details on state maternal COVID-19 reporting.

Technical Notes

A subset of states is providing information to the National Center for Health Statistics (NCHS) on reported cases of COVID-19 occurring during pregnancy for pregnancies ending in a live birth. The number of states reporting has increased from eight states and the District of Columbia (DC) in April 2020 to 14 states and DC in June 2020 through August 2021. The information from the reporting states is not representative of all women giving birth given that the incidence of COVID-19 cases varies substantially by state and by reporting period and that the reporting states are not a random sample of states. It is also important to note that states have varying approaches to capturing information on maternal COVID-19 and different time requirements for reporting birth information (see explanatory information and Table I below).

Nature and sources of data

National data on maternal COVID-19 are currently not available. Although a specific reporting item for maternal COVID-19 is not included on the U.S. Standard Certificate of Live Birth, a number of states are collecting information on maternal COVID-19 as part of the birth registration process and through other methods and are reporting this supplemental information to NCHS. The information presented for April 2020 through August 2021 represents 26.8% of all births during this period. Data for any additional jurisdictions that begin reporting maternal COVID-19 cases to NCHS will be included in future updates.

Maternal COVID-19 information is sent by the states to NCHS on a recurring basis independently of the standard birth record and of the standard birth record data transmission process. This information is then linked to the standard birth record using a unique identifier, which allows for detailed analysis of information on the birth record (1) by maternal COVID-19 status. The vast majority (99.7%) of cases of maternal COVID-19 reported for April 2020-August 2021 were linked to the corresponding birth record. Unlinked cases are those for which the standard birth record had not been received by NCHS at the time the linkage was performed.

It is important to note that:

  • Since reporting states are not a random sample of states, the statistical information shown in this report reflects the characteristics of the reporting states. For example, California accounts for 40.6% of  births in the 15 -jurisdiction Maternal COVID-19 reporting area in the current reporting period while only 11.5% of all U.S. births occurred in California during this period. The characteristics of mothers in California will be disproportionately reflected in the data for the reporting area compared to the total U.S. See Table II for the distributions of maternal COVID-19 cases and total  births by state for all reporting areas, and Table III for comparisons of selected results for three different reporting areas: the full reporting area, the reporting area excluding California, and California alone.
  • Certain jurisdictions (California, Maryland, Ohio, North Dakota, and Tennessee) report only confirmed (and not presumed) cases of COVID-19.
      • In states where only confirmed cases of COVID-19 are reported, there is likely to be an undercount of births to mothers with COVID-19 and an overcount of births to mothers without COVID-19. As a result, differences in maternal characteristics and infant outcomes between the COVID-19 and non-COVID-19 groups may be biased.
  • The information on COVID-19 cases shown may not include all cases of maternal COVID-19 that occurred in the reporting area during the time period indicated, that is, information on cases occurring earlier in the study period may not have been reported due to lack of widespread testing in early 2020 and information on some cases may not have been provided to the state prior to the submission of monthly data to NCHS.
  • States have different methods for collecting maternal COVID-19 information. Some states have modified their state birth certificates to include a COVID-19 data item. Other states are identifying cases through infectious disease surveillance; still others are using a combination of these two methods (see Table I below).
  • These data are reported to NCHS outside of the usual process for submission of standard birth certificate data and do not undergo standard NCHS review prior to posting.

Maternal COVID-19 reporting area

Fourteen states and the District of Columbia have provided data as of 10/18/21, although it is important to note that the number of reporting areas was not constant over the time period for which these data are shown. Eight states and DC reported maternal COVID-19 to NCHS for April 2020, ten states and DC for May, and 14 states and DC for June 2020–August 2021. Characteristics of the reporting area are a function of the states participating and the length of time that they have been reporting. Table 1 includes data for all cases reported by these states over the April 2020–August 2021 time period since the purpose of this analysis was not to examine trends over time, but rather to compare the characteristics of births to women with, and without, COVID-19 during pregnancy. A comparison of results for the full reporting area/period shown in Table 1 with those for a consistent eight-state and DC reporting area for April 2020–August 2021 shows essentially similar results in terms of maternal characteristics and birth outcomes (data available upon request).

If additional states begin collecting and reporting information on maternal COVID-19, their data will be added to future updates.

Table I. Reporting specifications for maternal COVID-19 by state: 14 states and the District of Columbia, April 2020-August 2021

 

 

Jurisdiction
 

Date data collection began

 

 

Data collection method

Table
Alabama 3/1/2020 Reports confirmed or presumed cases of maternal COVID-19 reported in the medical notes section of the electronic birth reporting system and birth database. Also matches birth file with COVID-19 positive tests from Alabama National Electronic Disease Surveillance System.
Alaska 4/16/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Other Infections of Interest” section of the birth certificate item “Infections present and/or treated during this pregnancy.”
Arkansas 5/21/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Infections present and/or treated during this pregnancy” item of the birth certificate.
California 6/10/2020 Reports confirmed cases of maternal COVID-19 reported in the “Complications and Procedures of Pregnancy and Concurrent Illnesses” item of the birth certificate.
District of Columbia 3/1/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Infections present and/or treated during this pregnancy” and “Characteristics of Labor and Delivery” items of the birth certificate. Cases are verified using hospital medical records.
Idaho 5/1/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Infections present and/or treated during this pregnancy” item of the birth certificate.
Maine 6/1/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Pregnancy Factors” section of the birth certificate item  “Obstetric Procedures”.
Maryland 4/8/2020 Developed a COVID-19 birth data collection form for completion by birthing facilities for mothers with confirmed (positive laboratory test) disease.
New Hampshire 4/8/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Other Infections” section of the birth certificate item “Infections present and/or treated during this pregnancy.”
North Dakota 3/1/2020 Requires birthing hospitals to submit paper-based monthly reports identifying COVID-19 positive mothers.
Ohio 3/1/2020 Links birth file with the Ohio Disease Reporting System to identify confirmed COVID-19 cases.
Oklahoma 6/19/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Infections present and/or treated during this pregnancy” item of the birth certificate.
Oregon 6/15/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Infections present and/or treated during this pregnancy” item of the birth certificate.
Tennessee 3/4/2020 Links birth file with the Tennessee National Electronic Disease Surveillance System Base System to identify confirmed COVID-19 cases during pregnancy.
West Virginia 4/13/2020 Indicates that confirmed or presumed COVID-19 was present during pregnancy in the “Other Infections” section on the birth certificate item “Infections present and/or treated during this pregnancy.”

Completeness and representativeness of data

Differences in reporting methods used by states to identify cases of maternal COVID-19 may result in varying levels of completeness by state. While most states report both confirmed or presumed COVID-19 during pregnancy, five states — California, Maryland, Ohio, North Dakota, and Tennessee –routinely report only confirmed COVID-19 cases. Limited information is available on the quality of infection data reported on the birth certificate, however, underreporting of specific infections has been observed in some jurisdictions (2); accordingly, maternal COVID-19 may also be underreported and the cases reported to NCHS may not be representative of all maternal COVID-19 cases occurring in that jurisdiction.

The incidence of COVID-19 cases among the general population can vary substantially by state and by time period. Since the reporting states do not represent a random sample of states the results shown in Table 1 for the maternal COVID-19 reporting states are not representative of the total U.S., as is illustrated by comparing maternal characteristics from these states to the total U.S. For births occurring during April 2020-June 2021 the maternal COVID-19 reporting states combined (taking into account the dates at which each state began reporting maternal COVID-19) had a larger percentage of Hispanic births than the total U.S. (25.7% compared with 24.1%), and a smaller percentage of non-Hispanic white (50.2% vs. 52.0%) and non-Hispanic black (12.7% vs. 14.6%) births. The preterm birth rate for the maternal COVID-19 reporting area was lower than that of the entire U.S. (9.97% compared with 10.21%).

State of Occurrence

Maternal COVID-19 cases are reported by state of occurrence, which is the state in which the birth took place. State of occurrence may not be the same as the state of residence. Birth data are typically reported by state of residence.

Table II. Distribution of confirmed or presumed cases of Maternal COVID-19 during pregnancy and distribution of total births, by reporting area: April 2020-August 2021
Alabama 12.3 6.2
Alaska 0.4 0.9
Arkansas2 3.6 3.5
California3 29.8 40.6
District of Columbia 1.4 1.3
Idaho2 1.4 2.3
Maine3 1.0 1.2
Maryland 4.0 7.1
New Hampshire 0.3 1.3
North Dakota 0.3 1.3
Ohio 23.1 14.4
Oklahoma3 4.6 4.5
Oregon3 2.8 3.9
Tennessee 14.4 9.5
West Virginia 0.6 1.9
Total4 100.0 99.9
Table

 

 

 

Reporting area

Percent distribution
April 2020-August 2021
Yes
COVID-191
All births

1Confirmed or presumed COVID-19. Confirmed cases only are included for California, Maryland, Ohio, North Dakota, and Tennessee.
2Began reporting in May, 2020
3Began reporting in June, 2020
4May not add to 100.0 percent due to rounding error.

Table III. Confirmed or presumed cases of Maternal COVID-19 during pregnancy, by selected maternal and infant characteristics: Selected reporting areas and months, 2020
Number
Total 44,409 1,454,324 31,163 858,929 13,246 595,395
Maternal characteristics
Percent distribution
Race and Hispanic origin
Total2 100.0 100.0 100.0 100.0 100.0 100.1
Non-Hispanic white3 46.7 50.3 58.5 64.7 19.3 29.3
Non-Hispanic black3 15.7 12.2 20.7 16.9 4.1 5.4
Non-Hispanic Asian3 4.3 7.6 2.4 3.2 8.9 14.0
Non-Hispanic other4 3.1 3.9 3.3 4.3 2.5 3.4
Hispanic5 30.2 26.0 15.1 10.9 65.2 48.0
Age of mother in years
Total2 100.1 100.0 100.2 100.1 100.0 100.0
Under 20 5.4 4.2 5.6 5.0 4.9 3.1
20-24 21.4 18.1 22.6 20.7 18.7 14.2
25-29 29.8 27.8 30.8 29.6 27.4 25.3
30-34 26.7 29.8 26.4 28.2 27.6 32.0
35-39 13.6 16.3 12.2 13.7 16.8 20.2
40 or more 3.2 3.8 2.6 2.9 4.6 5.2
Educational attainment
Total2,6 100.0 100.1 100.0 100.0 100.0 100.1
Less than High School 15.4 11.3 14.2 11.7 18.5 10.6
High School graduate or GED 30.0 26.7 29.8 27.5 30.5 25.4
Some college 20.6 19.8 20.3 19.9 21.5 19.8
Associate degree 8.0 8.0 8.7 8.4 6.3 7.4
Bachelor's degree 16.7 21.0 17.3 19.9 15.3 22.6
Master's degree 7.2 10.0 7.6 9.6 6.0 10.6
Doctorate 2.1 3.3 2.1 3.0 1.9 3.7
Percentage
Source of Payment – Medicaid 48.8 41.2 47.5 42.4 51.9 39.4
ICU admission 0.5 0.2 0.5 0.2 0.6 0.2
Infant characteristics
Total preterm7 11.67 10.02 11.79 10.78 11.40 8.94
   34-36 weeks 8.59 7.35 8.68 7.83 8.37 6.65
   Less than 34 weeks 3.08 2.68 3.11 2.95 3.03 2.29
Low birthweight8 8.82 7.99 9.07 8.65 8.23 7.05
   Very low birthweight9 1.52 1.31 1.55 1.47 1.43 1.07
NICU admission 10.0 8.8 10.0 9.5 10.1 7.8
Infant living10 99.8 99.8 99.7 99.7 99.8 99.9
Table

 

 

 

Maternal or infant characteristic

All reporting areas Reporting area excluding California California only
April 2020-August 2021 April 2020-August 2021 June 2020-August 2021
Yes
COVID-191
No
COVID-19
Yes
COVID-191
No
COVID-19
Yes
COVID-191
No
COVID-19

1 Confirmed or presumed COVID-19. Confirmed cases only are included for California, Maryland, Ohio, North Dakota, and Tennessee.
2 May not add to 100.0 percent due to rounding error.
3 Race and Hispanic origin are reported separately on birth certificates; persons of Hispanic origin may be of any race. In this table, non-Hispanic women are classified by race. Race categories are consistent with the 1997 Office of Management and Budget standards; see reference 1. Single-race is defined as only one race reported on the birth certificate.
4 Includes births to race and origin groups not shown separately, such as non-Hispanic American Indian or Alaska Native, non-Hispanic Native Hawaiian or Other Pacific Islander, non-Hispanic multiple race and Hispanic origin not stated.
5 Includes all persons of Hispanic origin of any race; see reference 1.
6 Includes women who may not have had time to complete their education.
7 Gestational age in completed weeks; based on the obstetric estimate of gestation.
8 Less than 2,500 grams
9 Less than 1,500 grams
10 Infant living at time of discharge or transfer from hospital.

NOTES: Reporting area includes Alabama, Alaska, Arkansas, California, District of Columbia, Idaho, Maine, Maryland, New Hampshire, North Dakota, Ohio, Oklahoma, Oregon, Tennessee, and West Virginia. See Technical notes for numbers and distributions of cases by state and details on state maternal COVID-19 reporting.

Source

NCHS, National Vital Statistics System.

Suggested Citation

Osterman MJK, Valenzuela CP, Martin JA. Maternal and Infant Characteristics Among Women with Confirmed or Presumed Cases of Coronavirus Disease (COVID-19) During Pregnancy. National Center for Health Statistics. National Vital Statistics System. 2021.

References

1. National Center for Health Statistics. Vital statistics data available. Natality public use. Hyattsville, MD: National Center for Health Statistics. Published annually. Available from: http://www.cdc.gov/nchs/data_access/VitalStatsOnline.htm
2. Gregory ECW, Ely DM. Trends and characteristics of sexually transmitted infections during pregnancy: United States, 2016-2018. National Vital Statistics Report. Vol 69 (3): Hyattsville, Maryland. National Center for Health Statistics. 2020.

Page last reviewed: November 3, 2021