Birth outcomes across the spectrum of maternal age: dissecting aging effect versus confounding by social and medical determinants

Olapeju, Bolanle; Hong, Xiumei; Wang, Guoying; Summers, Amber; Burd, Irina; Cheng, Tina L.; Wang, Xiaobin

doi:10.1186/s12884-021-04077-w

Table 1 Characteristics of the study population by maternal age groups (N = 8509)

From: Birth outcomes across the spectrum of maternal age: dissecting aging effect versus confounding by social and medical determinants

Maternal Characteristics	< 20 years		20–29 years		30–39 years		40+ years		Total		P-value^a
Maternal Characteristics	N	%	N	%	N	%	N	%	N	%
Total	907	100	4305	100	2960	100	337	100	8509	100
Sociodemographic
Race/ethnicity											< 0.001
Black^b	488	53.8	2073	48.2	1613	54.5	219	65.0	4393	51.6
Non-Black	419	46.2	2232	51.8	1347	45.5	118	35.0	4116	48.4
Parity											< 0.001
Nulliparous	760	83.8	2103	48.9	751	25.4	49	14.5	3663	43.0
Multiparous	147	16.2	2202	51.1	2209	74.6	288	85.5	4846	57.0
Education (n = 8349)											< 0.001
< College	813	91.3	2733	64.9	1658	56.9	219	66.0	5423	65.0
≥ College	77	8.7	1479	35.1	1257	43.1	113	34.0	2926	35.0
Marital Status (n = 8340)											< 0.001
Not married	842	94.8	2984	70.8	1473	50.7	170	51.5	5469	65.6
Married	46	5.2	1232	29.2	1433	49.3	160	48.5	2871	34.4
Public assistance^c (n = 8378)											0.580
No	157	17.5	813	19.2	572	19.6	63	18.9	1605	19.2
Yes	738	82.5	3423	80.8	2341	80.4	271	81.1	6773	80.8
Yearly Income in US$ (n = 7616)											< 0.001
≥ $30,000	18	2.3	470	12.1	547	20.7	59	19.2	1094	14.4
< $30,000	321	40.1	1861	48.1	1167	44.2	138	44.8	3487	45.8
Don’t know	461	57.6	1538	39.8	925	35.1	111	36.0	3035	39.9
Place of birth (n = 8310)											< 0.001
Not US born	309	34.7	2400	57.0	2096	72.8	270	81.3	5075	61.1
US born	581	65.3	1809	43.0	783	27.2	62	18.7	3235	38.9
Biomedical
Body Mass Index (n = 7930)											< 0.001
< 19	97	11.3	324	8.1	109	3.9	6	1.9	536	6.8
19–24	467	54.4	1899	47.5	1147	41.5	118	37.9	3631	45.8
25–29	197	22.9	1003	25.1	853	30.9	103	33.1	2156	27.2
≥ 30	98	11.4	770	19.3	655	23.7	84	27.0	1607	20.3
Hypertensive disorders of pregnancy (n = 8498)											< 0.001
No	810	89.3	3830	89.1	2519	85.2	272	80.7	7431	87.4
Yes	97	10.7	467	10.9	438	14.8	65	19.3	1067	12.6
Pregestational/gestational diabetes (n = 8500)											< 0.001
No	876	96.7	3957	92.1	2524	85.3	260	77.2	7617	89.6
Yes	30	3.3	340	7.9	436	14.7	77	22.8	883	10.4
*Behavioral*
Father of baby support (n = 7829)											< 0.001
None/Little	201	24.3	634	16.1	383	14.0	55	17.6	1273	16.3
Some	278	33.6	1474	37.3	993	36.3	126	40.4	2871	36.7
Excellent	349	42.1	1842	46.6	1363	49.8	131	42.0	3685	47.1
Family support (n = 7917)											0.014
None/Little	47	5.6	301	7.5	215	7.7	30	9.3	593	7.5
Some	368	44.2	1786	44.8	1225	44.1	167	51.9	3546	44.8
Excellent	418	50.2	1900	47.7	1335	48.1	125	38.8	3778	47.7
Major stressful events in pregnancy											0.030
No	663	75.8	3136	75.5	2262	79.1	256	79.3	6317	76.9
Yes	212	24.2	1017	24.5	598	20.9	67	20.7	1894	23.1
Smoking cigarettes (n = 8441)											< 0.001
Never	717	79.3	3321	77.8	2478	84.4	289	87.0	6805	80.6
Ever	187	20.7	949	22.2	457	15.6	43	13.0	1636	19.4
Drinking alcohol (n = 8201)											0.606
Never	798	91.3	3747	90.6	2630	91.5	290	90.6	7465	91.0
Ever	76	8.7	387	9.4	243	8.5	30	9.4	736	9.0
Multivitamin supplement intake at least 3 times a week throughout pregnancy (n = 7496)											< 0.001
No	273	34.3	1050	27.7	587	22.4	71	24.5	1981	26.4
Yes	524	65.7	2742	72.3	2030	77.6	219	75.5	5515	73.6

^a p-value from chi square tests of association; ^b Maternal self-report as Black, African American, Haitian or Cape Verdian;^c receipt of public assistance including: WIC (Women Infants and Children), Food Stamps, AFDC (Aid to Families with Dependent Children), Housing assistance or Fuel assistance

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ISSN: 1471-2393

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