Socio‑demographic characteristics of respondents
In this study, 356 participants were included. From these participants, 89 were preterm newborns (cases) and 267 were term newborns as controls with 100% response rate. The median age of mothers was 25 ± 8 (IQR) years in case group and 26 ± 7 (IQR) years in control group with a minimum of 17 and a maximum of 45 years. The paternal median age was 31 ± 7 (IQR) years ranges from 20 to 60 years. Regarding religion, 50 (56.2%) cases and 129 (48.3%) controls were Orthodox Christian. Majority of the respondents, 69 (77.5%) cases and 220 (82.4%) controls were married and living together. Concerning the educational level of parents, 34 (38.2%) mothers and 27 (30.4%) fathers in the case group had no formal education while 108 (44.4%) mothers and 89 (41.1%) fathers in the control group. About occupation, 46 (51.7%) cases and 132 (49.4%) controls were housewives. Forty-eight (53.9%) newborns in case-group and 148 (55.4%) newborns in control-group were male in sex. (Table 1)
Table 1: Distribution of socio-demographic characteristics among mothers who gave birth at public hospitals of Northeast Amhara, Ethiopia, 2019
Variable
|
Category
|
Cases (%)
|
Controls (%)
|
Total
|
Residence
|
Rural
|
42 (47.2%)
|
98 (36.7%)
|
140 (39.3%)
|
Urban
|
47 (52.8%)
|
169 (63.3%)
|
216 (60.7%)
|
Age of mother
|
<20
|
6 (6.7%)
|
10 (3.7%)
|
16 (4.5%)
|
20-34
|
68 (76.4%)
|
226 (84.6%)
|
294 (82.6%)
|
≥35
|
15 (16.9%
|
31 (11.6%)
|
46 (12.9%)
|
Educational status
|
Not able to read and write
|
20 (22.5%)
|
58 (21.7%)
|
78 (21.9%)
|
Able to read and write
|
14 (15.7%)
|
50 (18.7%)
|
64 (18.0%)
|
Primary education
|
19 (21.3%)
|
58 (21.7%)
|
77 (21.6%)
|
Secondary education
|
23 (25.8%)
|
60 (22.5%)
|
83 (23.3%)
|
Higher education
|
13 (14.6%)
|
41 (15.4%)
|
54 (15.2%)
|
Marital status
|
Married
|
69 (77.5%)
|
220 (82.4%)
|
289 (81.2%)
|
Separated
|
16 (18.0%)
|
30 (11.2%)
|
46 (12.9%)
|
Single/Divorced/Widowed
|
4 (4.5%)
|
17 (6.4%)
|
21 (5.9%)
|
Religion
|
Orthodox
|
50 (56.2%)
|
129 (48.3%)
|
179 (50.3%)
|
Muslim
|
33 (37.1%)
|
120 (44.9%)
|
153 (43.0%)
|
Protestant
|
5 (5.6%)
|
13 (4.9%)
|
18 (5.1%)
|
Catholic
|
1 (1.1%)
|
5 (1.9%)
|
6 (1.7%)
|
Occupational status
|
Housewife
|
46 (51.7%)
|
132 (49.4%)
|
178 (50.0%)
|
Farmer
|
10 (11.2%)
|
30 (11.2%)
|
40 (11.2%)
|
Merchant
|
14 (15.7%)
|
40 (15.0%)
|
54 (15.2%)
|
Government/NOGs employee
|
19 (21.3%)
|
65 (24.3%)
|
84 (23.6%)
|
Educational status of father
|
Not able to read and write
|
11 (12.4%)
|
45 (16.9%)
|
56 (15.7%)
|
Able to read and write
|
16 (18.0%)
|
54 (20.2%)
|
70 (19.7%)
|
Primary education
|
21 (23.6%)
|
49 (18.4%)
|
70 (19.7%)
|
Secondary education
|
25 (28.1%)
|
62 (23.2%)
|
87 (24.4%)
|
Higher education
|
16 (18.0%)
|
57 (21.3%)
|
73 (20.5%)
|
Age of father
|
<25
|
5 (5.6%)
|
10 (3.7%)
|
15 (4.2%)
|
25-29
|
30 (33.7%)
|
63 (23.6%)
|
93 (26.1%)
|
30-34
|
25 (28.1%)
|
95 (35.6%)
|
120 (33.7%)
|
35-39
|
16 (18.0%)
|
49 (18.4%)
|
65 (18.3%)
|
≥40
|
13 (14.6%)
|
50 (18.7%)
|
63 (17.7%)
|
Income (monthly)
|
<3000 Birr
|
52 (58.4%)
|
130 (48.7%)
|
182 (51.1%)
|
≥3000 Birr
|
37 (41.6%)
|
137 (51.3%)
|
174 (48.9%)
|
Infant sex
|
Male
|
48 (53.9%)
|
148 (55.4%)
|
196 (55.1%)
|
Female
|
41 (46.1%)
|
119 (44.6%)
|
|
Maternal Obstetric Related Factors
In this study, 66 (74.2%) cases and 113 (42.3%) controls had fewer than four ANC visits. Among these, 25 (28.1%) cases and 13 (4.9%) controls had no ANC follow up. Regarding Iron/folic acid supplementation, 44 (49.4%) cases and 45 (16.9%) controls had used no Iron/folic acid. About 13 (14.6%) cases and 7 (2.6%) controls had experienced anemia during pregnancy. The majority, 66 (74.2%) newborns in case-group and 217 (81.3%) newborns in control-group were born through spontaneous vaginal delivery. Concerning, past adverse birth outcome, 8 (25%) cases and 18 (17.3%) controls had one or more past adverse birth outcomes. Past adverse birth outcomes encountered were LBW 5 (15.6%), Stillbirth 3 (9.4%), and Abortion 3 (9.4%) among cases and 6 (5.8%), 9 (8.7%), and 7 (6.7%) among controls respectively. (Table 2)
Table 2
Maternal obstetric related factors among mothers who gave birth at public hospitals of Northeast Amhara, Ethiopia, 2019
Variable | Category | Cases (%) | Controls (%) | Total |
ANC Follow up | No | 25 (28.1%) | 13 (4.9%) | 38 (10.7%) |
< 4 | 41 (46.1%) | 100 (37.5%) | 141 (39.6%) |
≥ 4 | 23 (25.8%) | 154 (57.7%) | 177 (49.7%) |
Time of ANC initiation | First trimester | 23 (35.9%) | 97 (38.2%) | 120 (37.7%) |
Second trimester | 40 (62.5%) | 150 (59.1%) | 190 (59.7%) |
Third trimester | 1 (1.6%) | 7 (2.8%) | 8 (2.5%) |
Birth interval | No previous birth | 57 (64.0%) | 163 (61.0%) | 220 (61.8% ) |
< 24 months | 5 (5.6%) | 19 (7.1%) | 24 (6.7%) |
24–36 months | 20 (22.5%) | 68 (25.5%) | 88 (24.7%) |
≥ 37 months | 7 (7.9%) | 17 (6.4%) | 24 (6.7%) |
Parity | Primipara | 57 (64.0% ) | 163 (61.0%) | 220 (61.8%) |
Multipara | 32 (36.0%) | 104 (39.0%) | 136 (38.2%) |
Iron/folic acid supplementation | No | 44 (49.4%) | 45 (16.9% ) | 89 (25.0%) |
30–60 tabs | 36 (40.4%) | 144 (53.9%) | 180 (50.6%) |
> 60 tabs | 9 (10.1%) | 78 (29.2%) | 87 (24.4%) |
Anemia | No | 76 (85.4%) | 260 (97.4%) | 336 (94.4%) |
Yes | 13 (14.6%) | 7 (2.6%) | 20 (5.6%) |
Hemoglobin Level | < 11 g/dl | 25 (28.1%) | 35 (13.1%) | 60 (16.9%) |
≥ 11 g/dl | 64 (71.9%) | 232 (86.9% | 296 (83.1%) |
Mode of delivery | Spontaneous | 66 (74.2%) | 217 (81.3%) | 283 (79.5%) |
Induction | 18 (20.2%) | 16 (6.0%) | 34 (9.6%) |
C-section | 5 (5.6%) | 34 (12.7%) | 39 (11.0%) |
Pregnancy status | Unplanned | 22 (24.7%) | 33 (12.4%) | 55 (15.4%) |
Planned | 67 (75.3%) | 234 (87.6%) | 301 (84.6%) |
Maternal Rh factor | Positive | 59 (66.3%) | 187 (70.0%) | 246 (69.1%) |
Negative | 25 (28.1%) | 72 (27.0%) | 97 (27.2%) |
Unknown | 5 (5.6%) | 8 (3.0%) | 13 (3.7%) |
Maternal height | < 150 | 20 (22.5%) | 35 (13.1%) | 55 (15.4%) |
≥ 150 | 69 (77.5%) | 232 (86.9%) | 301 (84.6%) |
Maternal MUAC | < 23 | 44 (49.4%) | 88 (33.0%) | 132 (37.1%) |
≥ 23 | 45 (50.6%) | 179 (67.0%) | 224 (62.9%) |
History of adverse birth outcome | No | 24 (75.0% | 86 (82.7%) | 110 (80.9%) |
Yes | 8 (25.0%) | 18 (17.3%) | 26 (19.1%) |
Type of adverse birth outcome | LBW | 5 (15.6%) | 6 (5.8%) | 11 (8.1%) |
Stillbirth | 3 (9.4%) | 9 (8.7%) | 12 (8.8%) |
Abortion | 3 (9.4%) | 7 (6.7%) | 10 (7.4%) |
Table 3
Maternal infection and chronic disease related factors among mothers who gave birth at public hospitals of Northeast Amhara, Ethiopia, 2019
Variable | Category | Cases (%) | Controls (%) | Total |
Chronic medical illness | No | 83 (93.3%) | 253 (94.8%) | 336 (94.4%) |
Yes | 6 (6.7%) | 14 (5.2%) | 20 (5.6%) |
Type of medical illness | HPN | 3 (3.4%) | 4 (1.5%) | 7 (2.0%) |
DM/KD/LD?TD/ | 4 (4.49%) | 10 (3.74%) | 14 (3.93%) |
Maternal infection | UTI | 10 (11.2%) | 24 (9.0%) | 34 (9.6%) |
Malaria | 1 (1.1%) | 4 (1.5%) | 5 (1.4%) |
TB | 1 (1.1%) | 5 (1.9%) | 6 (1.7%) |
HIV/AIDS | 0 (%0) | 8 (3.0%) | 8 (2.2%) |
Key: DM = diabetes mellitus, KD = kidney disease, LD = liver disease, TD = thyroid disorder |
Table 4
Behavioral factors among mothers who gave birth at public hospitals of Northeast Amhara, Ethiopia, 2019
Variable | Category | Cases (%) | Controls (%) | Total |
Alcohol drinking during pregnancy | No | 62 (69.7%) | 199 (74.5%) | 261 (73.3%) |
Yes | 27 (30.3%) | 68 (25.5%) | 95 (26.7%) |
Type of alcohol drunk | Tella | 19 (21.3%) | 56 (21.0% ) | 75 (21.1%) |
Areke | 6 (6.7%) | 7 (2.6%) | 13 (3.7%) |
Beer | 8 (9.0%) | 24 (9.0%) | 32 (9.0%) |
Wine/Tej | 7 (7.9%) | 7 (2.6%) | 14 (3.9%) |
Frequency of drinking | Daily/Weekly | 9 (33.3%) | 13 (19.1) | 22 (23.2%) |
Fortnightly/Monthly | 7 (25.9%) | 13 (19.1%) | 20 (21.0%) |
Occasionally | 11 (40.7%) | 42 (61.8%) | 53 (55.8%) |
Unit of alcohol per week (recent month) | No alcohol | 65 (73.0%) | 223 (83.5%) | 288 (80.9%) |
1–3 unit | 21 (23.6%) | 40 (15.0%) | 61 (17.1%) |
≥ 4 unit | 3 (3.4%) | 4 (1.5%) | 7 (2.0%) |
Khat chewing during pregnancy | No | 84 (94.4%) | 248 (92.9%) | 332 (93.3%) |
Yes | 5 (5.6%) | 19 (7.1%) | 24 (6.7%) |
Frequency of khat chewing | Daily/Weekly | 1 (20%) | 4 (21.1%) | 5 (20.8%) |
Fortnightly | 0 (0%) | 5 (26.3%) | 5 (20.8%) |
Monthly | 0 (0%) | 1 (5.3%) | 1 (4.2%) |
Occasionally | 4 (80%) | 9 (47.4%) | 13 (54.2%) |
Passive Smoking | No | 87 (97.8%) | 261 (97.8%) | 348 (97.8%) |
Yes | 2 (2.2%) | 6 (2.2%) | 8 (2.2%) |
Any medication during pregnancy | No | 74 (83.1%) | 227 (85.0%) | 301 (84.6%) |
Yes | 15 (16.9%) | 40 (15.0%) | 55 (15.4%) |
Frequency of medication use | Daily | 12 (80.0%) | 34 (85.0%) | 46 (83.6%) |
Weekly | 0 (0%) | 1 (2.5%) | 1 (1.8%) |
Occasionally | 3 (20.0%) | 5 (12.5%) | 8 (14.5%) |
Table 5
Bi-variable and Multi-variable analysis of determinants associated with preterm birth among mothers who gave birth at public hospitals of Northeast Amhara, Ethiopia, 2019
Variables | Category | Cases (%) | Controls (%) | COR (95% CI) | AOR (95% CI) |
Residence | Rural | 42 (47.2%) | 98 (36.7%) | 1.541 (0.949, 2.503) | 0.998(0.521,1.912) |
Urban | 47 (52.8%) | 169 (63.3%) | 1 | 1 |
Pregnancy status | Unplanned | 22 (24.7%) | 33 (12.4%) | 2.328 (1.273, 4.259) | 0.995(0.442,2.242) |
Planned | 67 (75.3%) | 234 (87.6%) | 1 | 1 |
ANC follow up | < 4 ANC visit | 66 (74.2%) | 113 (42.3%) | 3.911 (2.295, 6.665) | 2.267(1.205,4.264)** |
≥ 4 ANC visit | 23 (25.8%) | 154 (57.7%) | 1 | 1 |
Age of mother in years | < 19 | 6 (6.7%) | 10 (3.7%) | 1.240(0.379, 4.056) | 1.326(0.290,6.060) |
20–34 | 68 (76.4%) | 226 (84.6%) | 0.622(0.317, 1.219) | 1.009(0.419,2.431) |
≥ 35 | 15 (16.9%) | 31 (11.6%) | 1 | 1 |
PIH | No | 75 (84.3%) | 261 (97.8%) | 1 | 1 |
Yes | 14 (15.7%) | 6 (2.2%) | 8.120 (3.016, 21.858) | 4.453(1.276,15.536)** |
PROM | No | 77 (86.5%) | 259 (97%) | 1 | 1 |
Yes | 12 (13.5%) | 8 (3.0%) | 5.045 (1.991, 12.789) | 3.159(0.938,10.638) |
Congenital malformation | No | 74 (83.1%) | 262 (98.1%) | 1 | 1 |
Yes | 15 (16.9% ) | 5 (1.9%) | 10.622 (3.737, 30.186) | 6.160(1.896,20.013)* |
Iron/folic acid supplementation | No iron use | 44 (49.4%) | 45 (16.9% ) | 8.474(3.78718.962) | 4.175(1.632,10.680)* |
30–60 tabs | 36 (40.4%) | 144 (53.9%) | 2.167(0.9934.730) | 1.838(0.765,4.418) |
≥ 60 tabs | 9 (10.1%) | 78 (29.2%) | 1 | 1 |
Anemia during current pregnancy | No | 76 (85.4%) | 260 (97.4%) | 1 | 1 |
Yes | 13 (14.6%) | 7 (2.6%) | 6.353 (2.448, 16.489) | 4.776 (1.492, 15.285)* |
Hemoglobin level | < 11 mg/dl | 25 (28.1%) | 35 (13.1%) | 2.589 (1.445, 4.639) | 1.880(0.925,3.821) |
≥ 11 mg/dl | 64 (71.9%) | 232 (86.9% | 1 | 1 |
Height of Mothers | < 150 cm | 20 (22.5%) | 35 (13.1%) | 1.921 (1.042, 3.542) | 1.112(0.513, 2.411) |
≥ 150 cm | 69 (77.5%) | 232 (86.9%) | 1 | 1 |
MUAC | < 23 cm | 44 (49.4%) | 88 (33.0%) | 1.989 (1.221, 3.239) | 1.481(0.812,2.699) |
≥ 23 cm | 45 (50.6%) | 179 (67.0%) | 1 | 1 |
Income (monthly) | < 3000 EBR | 52 (58.4%) | 130 (48.7%) | 1.481 (0.912, 2.406) | 1.388(0.738,2.608) |
≥ 3000 EBR | 37 (41.6%) | 137 (51.3%) | 1 | 1 |
Key: COR = crude odds ratio, AOR = adjusted odds ratio, CI = confidence interval, *=P-value < 0.01, **=p-value ≤ 0.05 |
Fetal Related Factors
The mean gestational age among PTBs and term births were 34 ± 1.94 weeks and 39.02 ± 1.27 weeks, respectively. In the case group, 17 (19.1%) newborns were small for gestational age whereas 12 (4.5%) newborns in control group were low birth weight. Concerning fetal distress, 5 (5.6%) cases and 15 (5.6%) controls had fetal distress. On the other hand, 15 (16.9%) preterm newborns and 5 (1.9%) term newborns had a visible congenital/birth defect.
Current Obstetric Complications
During current pregnancy, about 23 (25.8%) cases and 27 (10.1%) controls had one or more of pregnancy-related complications. Pregnancy-related complications occurred among cases were APH 3 (3.4%), Pre-eclampsia 2 (2.2%), PROM 12 (13.5%), PIH 14 (15.7%), and Hyperemesis gravidarum 4 (4.5%) whereas 1 (0.4%), 3 (1.1%), 8 (3.0%), 6 (2.2%), and 11 (4.1%) controls had the same obstetric complications in the same order.
Maternal Infection And Chronic Disease Related Factors
About 6 (6.7%) cases and 14 (5.2%) controls had a chronic medical illness. Chronic hypertension was observed in 3 (3.4%) cases and 4 (1.5%) controls. Concerning maternal infections, UTI among 10 (11.2%) cases and 24 (9%) controls, and HIV/AIDS 8 (3.0%) among controls were found. Table-3
Behavioral And Lifestyle Related Factors
Twenty-seven (30.3%) cases and 68 (25.5%) controls were drunk alcohol. The alcoholic beverage drunk comprised of “Tella”, “Tej”, “Areke”, Beer, and Wine. The majority, 19 (21.3%) cases and 56 (21.0%) controls drunk “Tella”. Regarding Khat chewing during pregnancy, 5 (5.6%) cases and 19 (7.1%) controls were chewed khat. About 15 (16.9%) cases and 40 (15.0%) of their counterparts were used medication other than minerals, vitamins, and iron/folic acid prescribed or from the counter. (Table-4)
Determinants Associated With Preterm Birth
In bi-variable logistic regression analysis at 95% level of confidence, ANC follow up, pregnancy status, PIH, PROM, Congenital malformation, Iron/folic acid supplementation, Anemia and hemoglobin level during current pregnancy, Height of mothers, and MUAC were statistically significant with PTB. In multivariable logistic regression analysis at P-value ≤ 0.05, ANC follow up, PIH, Congenital malformation, Iron/folic acid consumption, and Anemia during current pregnancy remained significantly associated determinants of PTB.
The chance of being preterm among newborns whose mothers had had fewer than four ANC follow up was about 2 times more than newborns whose mothers had had four or more ANC follow up [AOR 2.267, Cl (1.205, 4.264)]. Newborns of mothers with PIH were four and half folds higher to be preterm [AOR 4.453 Cl (1.276, 15.536)] compared to newborns born from mothers with no PIH. Similarly, newborns whose mothers had not used iron/folic acid supplementation during current pregnancy were 4 times increased the risk to be born preterm [AOR 4.175, (1.632, 10.680)] compared to their counterparts. The odds of being preterm in newborns with a birth defect were 6 times higher [AOR 6.160, Cl (1.896, 20.013)] compared to newborns without a birth defect. Additionally, those newborns that born from mothers who had had anemia during current pregnancy were about 5 times higher to be born preterm [AOR 4.776 (1.492, 15.285)] than newborns whose mothers had no anemia. (Table-5)