Background
Methods
Information sources and search strategy
Selection criteria
Data extraction and assessment of risk of bias
Data synthesis and statistical analyses
Management of multiple comparisons
Subgroup and sensitivity analyses
Results
Study characteristics
Study (Country) | Study population (sample size) | Intervention | Control group | Intervention period | Potential conflicts of interest | Risk of bias |
---|---|---|---|---|---|---|
Prebiotics vs placebo | ||||||
Bergmann, 2008 (Germany) [44] | Healthy pregnant women (144) | Group 1: Flavored and acidified milk-based supplement, vitamins, minerals and Fructo-oligosaccharides Group 2: Flavored and acidified milk-based supplement, vitamins, minerals and Fructo-oligosaccharides and Docosahexaenoic acid | Placebo | From 21 to 37 weeks of pregnancy. | Yes | Low |
Probiotics vs placebo or treatment as usual | ||||||
Kalliomaki 2001 (Finland) [52] | Women carrying a fetus at risk of atopic disease (159) | L. rhamnosus GG | Placebo | 2–4 weeks before expected delivery | NR | Low |
Abrahamsson 2007 (Sweden) [45] | Women carrying a fetus at risk of allergies (232) |
L. reuteri
| Placebo | From 4 weeks before term until delivery | Yes | Low |
Niers, 2009, (Netherlands) [43] | Women carrying a fetus at risk of allergies (156) | B. animalis subsp. lactis W52 B. bifidum W23 Lc. lactis W58 | Placebo | Last 6 weeks of pregnancy | Yes | Unclear |
Laitinen 2009 (Finland) [23] | Healthy pregnant women (256) | Dietary counselling L. rhamnosus GG B. animalis subsp. lactis BB12 | Group 1: dietary counselling with placebo. Group 2: placebo only | From mean gestational week of 13.9 ± 1.6 until delivery | Yesb | Low |
Kim, 2010 (Korea) [42] | Women carrying a fetus at risk of allergies (112) | L. acidophilus AD031 B. bifidum BGN4 B. animalis subsp. lactis AD011 | Placebo | From 8 weeks before the expected delivery to delivery | NR | Unclear |
Allen, 2010 (United Kingdom) [50] | Mostly (91%) women carrying a fetus at risk of atopy (454) | L. salivarius CUL61 L. paracasei CUL08 B. animalis subsp. Lactis CUL34 B. bifidum CUL20 | Placebo | Last month of pregnancy | Yes | Low |
Dotterund 2010 (Norway) | Healthy pregnant women (415) | (Probiotic milk) L. rhamnosus GG L. acidophilus LA5 B. animalis subsp. Lactis Bb-12 | Placebo | From 36 weeks of gestation to delivery | Yes | Low |
Asemi 2011 (Iran) [47] | Healthy pregnant women (82) | (Probiotic yogurt) L. delbrueckii subsp. bulgaricus L. acidophilus LA5 B. animalis subsp. lactis BB12
S. thermophiles
| Conventional yogurt (containing starter cultures of S. thermophilus and L. bulgaricus) | From 28 to 37 weeks of gestation | Yesc | Unclear |
Boyle 2011 (Australia) [48] | Women carrying a fetus at risk of allergies (250) | L. rhamnosus GG | Placebo | 36 weeks gestation until delivery | Yesa | Low |
Krauss-Silva 2011 (Brazil) [41] | Healthy pregnant women with Nugent scores ≥4 (644) | L. rhamnosus GR1 L. reuteri RC14 | Placebo | Six to twelve weeks (depending on the participant’ s gestational age at the time of enrolment) up until the 24th -26th week of gestation. | Uncleard | Low |
Rautava, 2012, (Finland) [31] | Women carrying a fetus at risk of allergies (241) | Group 1: Dietary food supplement L. rhamnosus LPR B. longum BL999 Group 2: Dietary food supplement, L. paracasei ST11 B. longum BL999 | Placebo | Last two months of pregnancy | Yes | Low |
Ou, 2012, (Taiwan) [53] | Pregnant women with allergies (191) | L. rhamnosus GG | Placebo | From 24 weeks of gestation to delivery | NR | Low |
Hantoushzadeh, 2012, (Iran) [40] | Women with symptomatic bacterial vaginosis (310) | (Probiotic yogurt) L. delbrueckii subsp. bulgaricus
L. acidophilus
B. animalis subsp. lactis
S. thermophiles
| Orally-administered clindamycin (300 mg twice a day for 1 week) | One week starting at mean week of gestation 36.43 ± 1.32 | Uncleare | Low |
Lindsay 2014 (Ireland) [37] | Obese women (165) | L. salivarius UCC118 | Placebo | Four weeks starting at 24th week of gestation | Unclearf | Low |
Dolatkhah, 2015, (Iran) [36] | Women with gestational diabetes mellitus (64) | L. acidophilus LA5 L. delbrueckii subsp. bulgaricus LBY-27 B. animalis subsp. lactis BB12 S. thermophiles STY31 | Placebo | Eight weeks, starting between 24 and 28 + 6 weeks of gestation | Yesg | Low |
Lindsay 2015 (Ireland) [37] | Women with impaired glucose tolerance or gestational diabetes mellitus (149) | L. salivarius UCC118 | Placebo | From mean week of gestation 31.5 ± 2.2 until delivery | Yes | Low |
Mastromarino 2015 (Italy) [54] | Healthy pregnant women (67) |
L. acidophilus
L. plantarum
L. paracasei
L. delbrueckii subsp. bulgaricus
B. longum
B. breve
B. infantis
S. thermophiles
| Placebo | From the 36th week of pregnancy until delivery | No | Low |
Karamali, 2016 (Iran) [46] | Women with gestational diabetes mellitus (60) |
L. acidophilus
L. casei
B. bifidum
| Placebo | Six weeks starting at 24–28 weeks of gestation | No | Low |
Jafarnejad 2016 (Iran) [49] | Women with gestational diabetes mellitus (82) |
L. acidophilus
L. plantarum
L. paracasei
L. delbrueckii subsp. bulgaricus
B. breve
B. longum
B. infantis
S. thermophilus
| Placebo | Eight weeks starting at a mean gestational week 26.4 (SD not reported) | No | Unclear |
Ho 2016 (Taiwan) [35] | Group B Streptococcus- positive pregnant women (110) | L. rhamnosus GR1 L. reuteri RC14 | Placebo | Intervention lasted a mean of 21.1 ± 5.5 days until delivery. | No | Low |
Results by intervention type
Outcome | Intervention | Studies | N | I2 | RR/MD (95% CI) |
---|---|---|---|---|---|
PTB < 34 | Probiotics | 5 | 1017 | 0% | RR 1.03 (0.29–3.64) |
Prebiotics | 0 | – | – | – | |
PTB < 37 | Probiotics | 11 | 2484 | 0% | RR 1.08 (0.71–1.63) |
Prebiotics | 1 | 116 | – | RR 1.43 (0.06–34.17) | |
Gestational age (weeks) | Probiotics | 8 | 1133 | 0% | MD 0.07 weeks (-0.09–0.23) |
Prebiotics | 1 | 115 | – | MD -0.37 weeks (-1.14–0.40) | |
Birth weight (grams) | Probiotics | 10 | 1608 | 0% | MD 10.66 g (-35.85–57.18) |
Prebiotics | 1 | 116 | – | MD -63.95 g (-262.02–134.12) | |
SGA | Probiotics | 3 | 318 | 50% | RR 1.03 (0.35–3.06) |
Prebiotics | 0 | – | – | – | |
LGA | Probiotics | 3 | 316 | 0% | RR 0.96 (0.47–1.94) |
Prebiotics | 0 | – | – | – | |
GDM | Probiotics | 2 | 355 | 0% | RR 1.25 (0.61–2.56) |
Prebiotics | 0 | – | – | – | |
PPROM | Probiotics | 2 | 366 | 0% | RR 1.37 (0.63–2.99) |
Prebiotics | 0 | – | – | – |
Results by genus
Outcome | Intervention | Studies | N | I2 | RR/MD (95% CI) |
---|---|---|---|---|---|
PTB < 34 | Lactobacillus (& other) | 5 | 1017 | 0% | RR 1.03 (0.29–3.64) |
Bifidobacterium (& other) | 3 | 377 | 0% | RR 1.54 (0.27–8.73) | |
Streptococcus (& other) | 2 | 146 | 0% | RR 1.60 (0.20–12.69) | |
PTB < 37 | Lactobacillus (& other) | 10 | 2328 | 0% | RR 1.10 (0.72–1.68) |
Bifidobacterium (& other) | 7 | 1479 | 0% | RR 1.21 (0.75–1.96) | |
Streptococcus (& other) | 3 | 512 | 0% | RR 1.81 (0.80–4.10) | |
Gestational age (weeks) | Lactobacillus (& other) | 8 | 1133 | 0% | MD 0.07 weeks (-0.09–0.23) |
Bifidobacterium (& other) | 3 | 365 | 0% | MD 0.30 weeks (0.03–0.57) | |
Streptococcus (& other) | 1 | 66 | – | MD 0.40 weeks (-0.10–0.90) | |
Birth weight (grams) | Lactobacillus (& other) | 10 | 1608 | 0% | MD 10.66 g (-35.85–57.18) |
Bifidobacterium (& other) | 5 | 840 | 0% | MD 22.44 g (-40.58–85.46) | |
Streptococcus (& other) | 1 | 66 | – | MD -65.00 g (-301.73–171.73) | |
SGA | Lactobacillus (& other) | 3 | 318 | 50% | RR 1.03 (0.35–3.06) |
Bifidobacterium (& other) | 1 | 66 | – | RR 11.00 (0.63–191.27) | |
Streptococcus (& other) | 1 | 66 | – | RR 11.00 (0.63–191.27) | |
LGA | Lactobacillus (& other) | 3 | 316 | 0% | RR 0.96 (0.47–1.94) |
Bifidobacterium (& other) | 1 | 66 | – | RR 0.67 (0.12–3.73) | |
Streptococcus (& other) | 1 | 66 | – | RR 0.67 (0.12–3.73) | |
GDM | Lactobacillus (& other) | 2 | 355 | 0% | RR 1.25 (0.61–2.56) |
Bifidobacterium (& other) | 1 | 219 | – | RR 1.26 (0.56–2.83) | |
Streptococcus (& other) | 0 | – | – |
Not estimable
| |
PPROM | Lactobacillus (& other) | 2 | 366 | 0% | RR 1.37 (0.63–2.99) |
Bifidobacterium (& other) | 2 | 366 | 0% | RR 1.37 (0.63–2.99) | |
Streptococcus (& other) | 2 | 366 | 0% | RR 1.37 (0.63–2.99) |