Background
Methods
Subject selection
Variables | Case, n* (%) | Control, n* (%) | OR | 95% CI |
P-value |
---|---|---|---|---|---|
Blood type
| |||||
A | 158 (44.13) | 74 (52.11) | Reference | 0.369 | |
B | 28 (7.82) | 12 (8.45) | 1.09 | 0.53–2.27 | |
AB | 19 (5.31) | 5 (3.52) | 1.78 | 0.64–4.95 | |
O | 153 (42.74) | 51 (35.92) | 1.41 | 0.92–2.14 | |
Rh factor
| |||||
Positive | 275 (78.13) | 121 (85.82) | Reference | 0.052 | |
Negative | 77 (21.88) | 20 (14.18) | 1.69 | 0.99–2.90 | |
Mastitis in the family
| |||||
No | 191 (62.01) | 120 (83.92) | Reference | < 0.001 | |
Yes | 117 (37.99) | 23 (16.08) | 3.20 | 1.93–5.28 | |
Mastitis in previous breastfeedings** | |||||
No | 53 (48.62) | 54 (87.10) | Reference | < 0.001 | |
Yes | 56 (51.38) | 8 (12.90) | 7.13 | 3.10–16.39 | |
Breast cancer in the family
| |||||
No | 265 (74.44) | 99 (68.28) | Reference | 0.161 | |
Yes | 91 (25.56) | 46 (31.72) | 0.74 | 0.48–1.13 | |
Breast surgery
| |||||
No | 341 (94.99) | 141 (97.24) | Reference | 0.378 | |
Yes | 18 (5.01) | 4 (2.76) | 1.86 | 0.62–5.60 | |
Gastrointestinal disease
| |||||
No | 267 (74.17) | 113 (76.87) | Reference | 0.524 | |
Yes | 93 (25.83) | 34 (23.13) | 1.16 | 0.74–1.82 | |
Urinary infection
| |||||
No | 286 (78.36) | 128 (86.49) | Reference | 0.035 | |
Yes | 79 (21.64) | 20 (13.51) | 1.77 | 1.04–3.01 | |
Vaginal candidiasis
| |||||
No | 279 (76.23) | 127 (85.81) | Reference | 0.016 | |
Yes | 87 (23.77) | 21 (14.19) | 1.89 | 1.12–3.17 | |
Eye infection
| |||||
No | 335 (91.78) | 139 (93.92) | Reference | 0.408 | |
Yes | 30 (8.22) | 9 (6.08) | 1.38 | 0.64–2.99 | |
Ear infection
| |||||
No | 350 (95.89) | 145 (97.97) | Reference | 0.370 | |
Yes | 15 (4.11) | 3 (2.03) | 2.07 | 0.59–7.26 | |
Lip or nose infection
| |||||
No | 285 (77.87) | 125 (84.46) | Reference | 0.092 | |
Yes | 81 (22.13) | 23 (15.54) | 1.54 | 0.93–2.57 | |
Throat infection
| |||||
No | 258 (70.88) | 126 (85.71) | Reference | < 0.001 | |
Yes | 106 (29.12) | 21 (14.29) | 2.47 | 1.47–4.12 | |
Skin infection
| |||||
No | 301 (82.47) | 137 (92.57) | Reference | 0.003 | |
Yes | 64 (17.53) | 11 (7.43) | 2.65 | 1.35–5.18 | |
Allergies
| |||||
No | 250 (68.31) | 106 (71.62) | Reference | 0.461 | |
Yes | 116 (31.69) | 42 (28.38) | 1.17 | 0.77–1.78 | |
Autoimmune disease
| |||||
No | 352 (96.17) | 146 (98.65) | Reference | 0.237 | |
Yes | 14 (3.83) | 2 (1.35) | 2.90 | 0.65–12.94 | |
Asthma
| |||||
No | 347 (94.81) | 140 (94.59) | Reference | 0.922 | |
Yes | 19 (5.19) | 8 (5.41) | 0.96 | 0.41–2.24 | |
Anemia
| |||||
No | 305 (83.33) | 135 (91.84) | Reference | 0.013 | |
Yes | 61 (16.67) | 12 (8.16) | 2.25 | 1.17–4.32 | |
Gestational diabetes
| |||||
No | 342 (93.96) | 139 (93.92) | Reference | 0.987 | |
Yes | 22 (6.04) | 9 (6.08) | 0.99 | 0.45–2.21 | |
Thyroid disease
| |||||
No | 335 (91.78) | 133 (89.86) | Reference | 0.487 | |
Yes | 30 (8.22) | 15 (10.14) | 0.79 | 0.41–1.52 | |
Smoker
| |||||
No | 291 (80.17) | 116 (78.38) | Reference | 0.649 | |
Yes | 72 (19.83) | 32 (21.62) | 0.90 | 0.56–1.43 | |
Social drinker
| |||||
No | 195 (54.17) | 84 (57.14) | Reference | 0.541 | |
Yes | 165 (45.83) | 63 (42.86) | 1.13 | 0.77–1.66 |
Variables | Case, n* (%) | Control, n* (%) | OR | 95% CI |
P-value |
---|---|---|---|---|---|
Sex
| |||||
Female | 157 (42.90) | 78 (52.70) | Reference | ||
Male | 209 (57.10) | 70 (47.30) | 1.48 | 1.01–2.18 | 0.043 |
Blood type
| |||||
A | 104 (39.69) | 51 (48.11) | Reference | ||
B | 29 (11.07) | 4 (3.77) | 3.56 | 1.19–10.66 | 0.011 |
AB | 16 (6.11) | 1 (0.94) | 7.85 | 1.01–60.82 | |
O | 113 (43.13) | 50 (47.17) | 1.11 | 0.69–1.78 | |
Rh factor
| |||||
Positive | 240 (91.60) | 100 (94.34) | Reference | ||
Negative | 22 (8.40) | 6 (5.66) | 1.53 | 0.60–3.88 | 0.370 |
APGAR test
| |||||
< 9 | 26 (7.60) | 3 (2.26) | Reference | ||
> 9 | 316 (92.40) | 130 (97.74) | 0.28 | 0.08–0.94 | 0.049 |
Jaundice
| |||||
No | 244 (67.22) | 109 (74.15) | Reference | ||
Yes | 119 (32.78) | 38 (25.85) | 1.40 | 0.91–2.15 | 0.125 |
Hypoglycemia
| |||||
No | 357 (97.01) | 143 (96.62) | Reference | ||
Yes | 11 (2.99) | 5 (3.38) | 0.88 | 0.30–2.58 | 0.818 |
Eczema
| |||||
No | 347 (94.29) | 141 (95.27) | Reference | ||
Yes | 21 (5.71) | 7 (4.73) | 1.22 | 0.51–2.93 | 0.658 |
Thrush
| |||||
No | 328 (89.13) | 143 (96.62) | Reference | ||
Yes | 40 (10.87) | 5 (3.38) | 3.49 | 1.35–9.02 | 0.006 |
Micrognathia/Retrognathia
| |||||
No | 355 (96.47) | 147 (99.32) | Reference | ||
Yes | 13 (3.53) | 1 (0.68) | 5.38 | 0.70–41.52 | 0.132 |
Tongue-tie
| |||||
No | 255 (71.63) | 134 (90.54) | Reference | ||
Yes | 101 (28.37) | 14 (9.46) | 3.79 | 2.09–6.89 | < 0.001 |
Child hospitalized after birth
| |||||
No | 323 (90.73) | 134 (96.40) | Reference | ||
Yes | 33 (9.27) | 5 (3.60) | 2.74 | 1.05–7.16 | 0.033 |
Variables | Case, n* (%) | Control, n* (%) | OR | 95% CI |
P-value |
---|---|---|---|---|---|
Threatened miscarriage
| |||||
No | 308 (85.08) | 135 (91.22) | Reference | 0.063 | |
Yes | 54 (14.92) | 13 (8.78) | 1.82 | 0.96–3.45 | |
Breast/nipple pain during pregnancy
| |||||
No | 249 (70.94) | 117 (80.14) | Reference | 0.034 | |
Yes | 102 (29.06) | 29 (19.86) | 1.65 | 1.04–2.64 | |
Antibiotics during pregnancy
| |||||
No | 271 (77.87) | 122 (82.43) | Reference | 0.252 | |
Yes | 77 (22.13) | 26 (17.57) | 1.33 | 0.81–2.18 | |
Antifungal medication during pregnancy
| |||||
No | 317 (89.30) | 138 (93.24) | Reference | 0.170 | |
Yes | 38 (10.70) | 10 (6.76) | 1.65 | 0.80–3.41 | |
Analgesics during pregnancy
| |||||
No | 233 (64.36) | 105 (71.43) | Reference | 0.126 | |
Yes | 129 (35.64) | 42 (28.57) | 1.38 | 0.91–2.10 | |
Group B
Streptococcus
positive test
| |||||
No | 278 (79.89) | 115 (80.99) | Reference | 0.781 | |
Yes | 70 (20.11) | 27 (19.01) | 1.07 | 0.65–1.76 | |
Age range at last delivery
| |||||
< 25 | 5 (1.37) | 5 (3.45) | Reference | 0.305 | |
25-35 | 242 (66.12) | 95 (65.52) | 2.55 | 0.72–9.00 | |
> 35 | 119 (32.51) | 45 (31.03) | 2.64 | 0.73–9.57 | |
Primiparous/Multiparous
| |||||
Multiparous | 113 (30.87) | 62 (42.18) | Reference | 0.015 | |
Primiparous | 253 (69.13) | 85 (57.82) | 1.63 | 1.10–2.43 | |
Place of delivery
| |||||
Private clinic | 118 (33.71) | 25 (17.01) | Reference | 0.021 | |
Public hospital | 224 (64.00) | 113 (76.87) | 0.42 | 0.26–0.68 | |
Home | 8 (2.29) | 9 (6.12) | 0.19 | 0.07–0.54 | |
Type of delivery
| |||||
Vaginal | 267 (76.95) | 125 (85.03) | Reference | 0.042 | |
Caesarean section | 80 (23.05) | 22 (14.97) | 1.70 | 1.01–2.86 | |
Antibiotherapy during delivery
| |||||
No | 201 (57.59) | 100 (67.57) | Reference | 0.038 | |
Yes | 148 (42.41) | 48 (32.43) | 1.53 | 1.02–2.30 | |
Epidural analgesia during delivery
| |||||
No | 73 (20.17) | 48 (32.43) | Reference | 0.003 | |
Yes | 289 (79.83) | 100 (67.57) | 1.90 | 1.24–2.92 | |
First contact with child
| |||||
Immediately | 243 (66.21) | 114 (77.51) | Reference | 0.019 | |
10-60 min | 78 (21.25) | 25 (17.01) | 1.46 | 0.89–2.42 | |
> 60 min | 46 (12.53) | 8 (5.44) | 2.70 | 1.23–5.90 | |
Separation child-mother longer than 24 h
| |||||
No | 330 (89.92) | 144 (97.30) | Reference | 0.009 | |
Yes | 37 (10.08) | 4 (2.70) | 4.04 | 1.41–11.53 |
Variables | Case, n* (%) | Control, n* (%) | OR | 95% CI |
P-value |
---|---|---|---|---|---|
First breastfeed after birth
| |||||
Not immediately | 104 (28.42) | 24 (16.44) | Reference | 0.005 | |
Immediately | 262 (71.58) | 122 (83.56) | 0.50 | 0.30–0.81 | |
Problems to latch on the nipple at first
| |||||
No | 250 (67.93) | 125 (85.03) | Reference | < 0.001 | |
Yes | 118 (32.07) | 22 (14.97) | 2.68 | 1.62–4.44 | |
Time until the milk come in
| |||||
Hours | 50 (13.77) | 42 (29.17) | Reference | < 0.001 | |
One day | 66 (18.18) | 27 (18.75) | 2.05 | 1.12–3.77 | |
Several days | 247 (68.04) | 75 (52.08) | 2.77 | 1.70–4.49 | |
Breast milk amount
| |||||
Normal | 185 (50.27) | 94 (63.95) | Reference | 0.006 | |
Oversupply | 139 (37.77) | 48 (31.29) | 1.54 | 1.01–2.33 | |
Low supply | 44 (11.96) | 7 (4.76) | 3.19 | 1.39–7.36 | |
Types of breastfeeding
| |||||
Mixed | 272 (75.35) | 14 (9.52) | Reference | < 0.001 | |
Exclusive | 89 (24.65) | 133 (90.48) | 0.32 | 0.18–0.59 | |
Breastfeeding twins
/
Tandem nursing
| |||||
No | 349 (96.41) | 126 (87.50) | Reference | < 0.001 | |
Yes | 13 (3.59) | 18 (12.50) | 0.26 | 0.12–0.55 | |
Breastfeeding positions
| |||||
1 | 48 (13.30) | 22 (15.28) | 1.05 | 0.60–1.86 | 0.043 |
2 | 170 (47.09) | 82 (56.94) | Reference | ||
3 | 143 (39.61) | 40 (27.78) | 1.72 | 1.11–2.67 | |
Breastfeeding length
| |||||
5-15 min | 71 (26.59) | 36 (41.38) | Reference | < 0.001 | |
15-30 min | 112 (41.95) | 38 (43.68) | 1.49 | 0.87–2.58 | |
30-45 min | 37 (13.86) | 8 (9.20) | 2.35 | 0.99–5.56 | |
> 45 min | 47 (17.60) | 5 (5.75) | 4.77 | 1.74–13.03 | |
Time since breastfeeding started
| |||||
< 2 weeks | 31 (8.59) | 3 (2.59) | Reference | < 0.001 | |
2-4 weeks | 61 (16.90) | 8 (6.90) | 0.74 | 0.18–2.98 | |
1-3 months | 161 (44.60) | 22 (18.97) | 0.71 | 0.20–2.51 | |
3-6 months | 52 (14.40) | 51 (43.97) | 0.10 | 0.03–0.34 | |
6-12 months | 30 (8.31) | 15 (12.93) | 0.19 | 0.05–0.74 | |
> 12 months | 26 (7.20) | 17 (14.66) | 0.15 | 0.04–0.56 | |
Breast preference
| |||||
No | 233 (64.19) | 104 (71.23) | Reference | 0.129 | |
Yes | 130 (35.81) | 42 (28.77) | 1.38 | 0.91–2.10 | |
Consecutive feeds start with same breast
| |||||
No | 331 (92.72) | 137 (93.84) | Reference | 0.655 | |
Yes | 26 (7.28) | 9 (6.16) | 1.20 | 0.55–2.62 | |
One or two breast in each session
| |||||
1 | 138 (43.13) | 54 (40.30) | Reference | 0.578 | |
2 | 182 (56.88) | 80 (59.70) | 0.89 | 0.59–1.34 | |
Child skips one breastfeed session
| |||||
No | 274 (96.14) | 117 (99.15) | Reference | 0.195 | |
Yes | 11 (3.86) | 1 (0.85) | 4.70 | 0.60–36.80 | |
Pacifier
| |||||
No | 235 (66.38) | 112 (75.68) | Reference | 0.040 | |
Yes | 119 (33.62) | 36 (24.32) | 1.58 | 1.02–2.44 | |
Nipple shields
| |||||
No | 291 (82.20) | 141 (95.27) | Reference | < 0.001 | |
Yes | 63 (17.80) | 7 (4.73) | 4.36 | 1.95–9.77 | |
Bottle-feeding
| |||||
No | 260 (73.45) | 136 (91.89) | Reference | < 0.001 | |
Yes | 94 (26.55) | 12 (8.11) | 4.10 | 2.17–7.74 | |
Flat or inverted nipples
| |||||
No | 323 (91.24) | 147 (99.32) | Reference | 0.002 | |
Yes | 31 (8.76) | 1 (0.68) | 14.11 | 1.91–104.34 | |
Cream on nipples
| |||||
No | 171 (47.63) | 108 (75.52) | Reference | < 0.001 | |
Yes | 188 (52.37) | 35 (24.48) | 3.39 | 2.20–5.24 | |
Breast pumps
| |||||
No | 143 (39.29) | 101 (69.18) | Reference | < 0.001 | |
Yes | 221 (60.71) | 45 (30.82) | 3.47 | 2.30–5.22 | |
Breast pads
| |||||
No | 116 (32.77) | 56 (38.89) | Reference | 0.193 | |
Yes | 238 (67.23) | 88 (61.11) | 1.31 | 0.87–1.95 | |
Brassier use
| |||||
Day and night | 170 (48.99) | 72 (54.96) | Reference | 0.244 | |
Only day | 177 (51.01) | 59 (45.04) | 1.27 | 0.85–1.90 | |
Cracked nipples ( 1–5 )
**
| |||||
1 | 73 (19.84) | 77 (52.03) | Reference | < 0.001 | |
2 | 42 (11.41) | 26 (17.57) | 1.70 | 0.95–3.06 | |
3 | 50 (13.59) | 12 (8.11) | 4.39 | 2.17–8.91 | |
4 | 43 (11.68) | 9 (6.08) | 5.04 | 2.30–11.07 | |
5 | 160 (43.48) | 24 (16.22) | 7.03 | 4.02–12.01 | |
Antibiotics during breastfeeding
| |||||
No | 207 (56.71) | 126 (85.71) | Reference | < 0.001 | |
Yes | 158 (43.29) | 21 (14.29) | 4.58 | 2.76–7.60 | |
Antifungal medication during breastfeeding
| |||||
No | 280 (76.71) | 132 (89.80) | Reference | < 0.001 | |
Yes | 85 (23.29) | 15 (10.20) | 2.67 | 1,49–4,80 | |
Analgesics during breastfeeding
| |||||
No | 217 (58.97) | 109 (73.65) | Reference | < 0.001 | |
Yes | 151 (41.03) | 39 (26.35) | 1.94 | 1.28–2.96 | |
Non
-
steroidal anti
-
inflammatory drugs
| |||||
No | 218 (59.24) | 119 (80.41) | Reference | < 0.001 | |
Yes | 150 (40.76) | 29 (19.59) | 2.82 | 1.79–4.45 | |
Corticosteroids
| |||||
No | 355 (96.47) | 146 (98.65) | Reference | 0.297 | |
Yes | 13 (3.53) | 2 (1.35) | 2.67 | 0.60–11.99 |
Statistical analysis
Results
Variables | Adjusted OR | 95% CI |
P-value |
---|---|---|---|
Cracked nipples | 1.43 | 1.23–1.67 | < 0.0001 |
Antibiotics during breastfeeding | 5.38 | 2.85–10.14 | < 0.0001 |
Infant age | 0.92 | 0.87–0.96 | < 0.0001 |
Breast pumps | 2.78 | 1.68–4.58 | < 0.0001 |
Antifungal medication during breastfeeding | 3.81 | 1.35–10.76 | 0.0009 |
Mastitis in previous breastfeeding | 3.91 | 1.60–9.56 | 0.0014 |
Breast milk coming in later than 24 h | 2.26 | 1.24–4.12 | 0.0016 |
Mastitis in the family | 2.28 | 1.26–4.13 | 0.0028 |
Separation child-mother longer than 24 h | 6.40 | 1.77–23.18 | 0.0027 |
Cream on nipples | 1.91 | 1.13–3.24 | 0.0228 |
Throat infection | 2.05 | 1.10–3.80 | 0.0224 |