Table 1.
Characteristics of the included studies.
| Author/Country/Year of Acceptance for Publication/Trial Registration | Sample Size at Randomization | Groups Analyzed at Delivery | Microorganism (Strain)/Dosage (Posology) + Additional Interventions |
Administration Vehicle | Treatment Duration | Main Clinical Outcome | Risk of Bias Assessment | Conflict of Interest |
|---|---|---|---|---|---|---|---|---|
| Abrahamsson et al./Sweden/2007/Not reported [29] | 232 | Probiotic = 95 Placebo = 93 |
Lactobacillusreuteri (ATCC 55730)/1 × 108 CFU (daily) | Oil | From 36 WoG to delivery | Eczema and sensitization in offspring | Low | Existing conflict of interest |
| Ahmadi et al./ Iran/2016/IRCT201605085623N77 [30] |
70 | Synbiotic = 35 Placebo = 35 |
Lactobacillus acidophilus/2 × 108 CFU Lactobacillus casei/2 × 108 CFU Bifidobacterium bifidum/2 × 108 CFU + Inulin/0.8 g (daily) |
Oral capsule | Six weeks from 24–28 WoG | Insulin metabolism and lipid profile | Low | Potential conflict of interest |
| Ali Pourmirzaiee et al./ Iran/2020/IRCT201311004014882N7 [31] |
175 | Probiotic = 74 Placebo = 71 |
Lactobacillus reuteri (LR92, DSM 26866)/1 × 108 CFU (daily) |
Oral capsule | Four last weeks of gestation | Prevention of infantile colic | Low | Potential conflict of interest |
| Allen et al./United Kingdom/2009/ISRCTN26287422 [32] | 454 | Probiotic = 220 Placebo = 234 |
Lactobacillus salivarius (CUL61, NCIMB 30211)/6.25 × 109 CFU Lactobacillus paracasei (CUL08, NCIMB 30154) /1.25 × 109 CFU Bifidobacterium animalis (CUL34, NCIMB 30172)/1.25 × 109 CFU Bifidobacterium bifidum (CUL20, NCIMB 30153)/1.25 × 109 CFU (daily) |
Oral capsule | From last month of gestation to postpartum | Prevalence of adverse events | High | Existing conflict of interest |
| Asemi et al./Iran/2011/Not reported [33] | 82 | Probiotic = 37 Control = 33 |
Lactobacillus acidophilus (LA-5)/1 × 107 CFU Bifidobacterium animalis (Bb-12)/1 × 107 CFU (200 g daily) |
Yoghurt | Nine weeks from the third trimester of gestation | Insulin resistance and insulin levels | High | Potential conflict of interest |
| Asgharian et al./ Iran/2019/IRCT201604013706N31 [34] |
130 | Probiotic = 64 Control = 64 |
Lactobacillus acidophilus (LA-5)/5 × 108 CFU/g Bifidobacterium animalis (Bb-12)/5 × 108 CFU/g (100 g daily) |
Yoghurt | From 24 WoG to delivery | Glucose levels | Low | Potential conflict of interest |
| Bababi et al./ Iran/2008/IRCT20171010036697N1 [35] |
50 pregnant women with GDM | Probiotic = 24 Control = 24 |
Lactobacillus acidophilus/2 × 109 CFU/g Lactobacillus casei/2 × 109 CFU/g Bifidobacterium bidifum/2 × 109 CFU/g Lactobacillus fermentum/2 × 109 CFU/g (posology not clearly defined) |
Oral capsule | Six weeks from 24–28 WoG | Genetic and metabolic profile | Low | Potential conflict of interest |
| Badehnoosh et al./ Iran/2017/IRCT201611115623N91 [36] |
60 pregnant women with GDM | Probiotic = 30 Placebo = 30 |
Lactobacillus acidophilus/2 × 109 CFU/g Lactobacillus casei/2 × 109 CFU/g Bifidobacterium bidifum/2 × 109 CFU/g (Posology not clearly defined) |
Oral capsule | Six weeks from 24–28 WoG | Oxidative stress and inflammation biomarkers | Low | Potential conflict of interest |
| Boyle et al./Australia/2008/Cochrane Skin Group Trial No. 36 [37] | 250 | Probiotic = 125 Placebo = 125 |
Lactobacillus rhamnosus (GG)/1.8 × 1010 CFU (daily) |
Oral capsule | From 36 WoG to delivery | Risk of eczema during infancy | Low | Potential conflict of interest |
| Callaway et al./Australia/2018/ACTRN12611001208998 [38] | 433 overweight/obese pregnant women | Probiotic = 207 Placebo = 204 |
Lactobacillus rhamnosus (GG)/1 × 109 CFU Bifidobacterium animalis (Bb-12)/1 × 109 CFU (daily) |
Oral capsule | From 16 WoG to delivery | Prevalence of GDM | Low | No conflict of interest |
| Chen et al./China/2019/Not reported [14] | 32 | Probiotic = 14 Control = 16 |
Bifidobacterium longum/5 × 106 CFU Lactobacillus delbrueckii bulgaricus/5 × 105 CFU Streptococcus thermophilus/5 × 105 CFU (two tablets twice a day) |
Oral tablet | From 32 WoG to delivery | Gut microbiota and pro-inflammatory cytokine profile | High | Potential conflict of interest |
| Dewanto et al./Indonesia/2017/Not reported [39] | 110 | Probiotic = 36 Placebo = 38 |
Bifidobacterium animalis (HNO 19)/1 × 109 CFU (daily) |
Oral capsule | From third trimester to postpartum | Infant’s gut mucosal integrity | High | Existing conflict of interest |
| Dolatkhan et al./ Iran/2015/IRCT201405181597N3 [40] |
64 pregnant women with GDM | Probiotic = 27 Placebo = 29 |
Lactobacillus acidophilus (LA-5)/4 × 109 CFU Bifidobacterium animalis (Bb-12)/4 × 109 CFU Streptococcus thermophilus (STY-31)/4 × 109 CFU Lactobacillus delbrueckii bulgaricus (LBTY-27)/4 × 109 CFU (daily) |
Oral capsule | Eight weeks from 24–28 WoG | Glucose metabolism and gestational weight gain | High | Potential conflict of interest |
| Dotterud et al./Norway/2010/NCT00159523 [41] | 415 | Probiotic = 138 Placebo = 140 |
Lactobacillus rhamnosus (GG)/5 × 1010 CFU Bifidobacterium animalis (Bb-12)/5 × 1010 CFU Lactobacillus acidophilus (LA-5) /5 × 109 CFU (daily) |
Milk | From 36 WoG to postpartum | Atopic sensitization and allergic disease in offspring | Some Concerns | No conflict of interest |
| Fernández et al./ Spain/2015/NCT01505361 [42] |
108 | Probiotic = 55 Placebo = 53 |
Lactobacillus salivarius (PS2)/1 × 109 CFU (daily) |
Oral capsule | From 27–32 WoG to delivery | Mastitis | High | Potential conflict of interest |
| Gille et al./Germany/2016/ISRCTN40042090 [43] | 320 | Probiotic = 160 Placebo = 160 |
Lactobacillus rhamnosus (GR-1)/1 × 109 CFU Lactobacillus reuteri (RC-14)/1 × 109 CFU (daily) |
Oral capsule | Eight weeks from <12 WoG | Bacterial vaginosis | Low | Potential conflict of interest |
| Halkjær et al./Denmark/2020/NCT02508844 [44] | 50 obese pregnant women | Probiotic = 20 Placebo = 23 |
Bifidobacterium breve (DSM 24,732) Bifidobacterium longum (DSM 24,736) Bifidobacterium infantis (DSM 24,737) Lactobacillus delbrueckii bulgaricus (DSM 24,734)/ 1.12 × 109 CFU total (twice a day) |
Oral capsule | 14–20 WoG–delivery | Glucose homeostasis and gestational weight gain | Low | No conflict of interest |
| Ho et al./Taiwan/2015/NCT01577108 [45] | 110 GBS (+) pregnant women | Probiotic = 49 Placebo = 50 |
Lactobacillus rhamnosus (GR-1)/1 × 109 CFU Lactobacillus reuteri (RC-14)/1 × 109 CFU (twice a day) |
Oral capsule | From 35–37 WoG to delivery | Occurrence of streptococcus GBS | High | Potential conflict of interest |
| Jafarnejad et al./Iran/2016/Not reported [46] | 82 pregnant women with GDM | Probiotic = 41 Placebo = 41 |
Streptococcus thermophilus Bifidobacterium Breve Bifidobacterium longum Bifidobacterium infantis Lactobacillus Acidophilus Lactobacillus plantarum Lactobacillus Paracasei Lactobacillus delbrueckii Bulgaricus/112.5 × 109 CFU total (twice a day) |
Oral capsule | Eight weeks from 26 WoG (mean) | Glycemic control and inflammatory status | High | Potential conflict of interest |
| Jamilian et al./ Iran/2016/IRCT201503035623N38 [47] |
60 | Probiotic = 30 Placebo = 30 |
Lactobacillus acidophilus/2 × 109 CFU Lactobacillus casei/2 × 109 CFU Bifidobcterium bifidum/2 × 109 CFU (daily) |
Oral capsule | 12 weeks from 9 WoG | Metabolic profile, inflammatory factors and oxidative stress | Some Concerns | Potential conflict of interest |
| Jamilian et al./ Iran/2018/IRCT201706075623N119 [48] |
90 pregnant women with GDM | Probiotic = 29 Probiotic + Vitamin D = 30 Placebo = 28 |
Lactobacillus acidophilus/2 × 109 CFU Bifidobacterium bifidum/2 × 109 CFU Lactobacillus reuteri/2 × 109 CFU Lactobacillus fermentum/2 × 109 CFU (daily) |
Oral capsule | Six weeks from 24–28 WoG | Metabolic profile, inflammatory factors and oxidative stress | High | Potential conflict of interest |
| Kalliomaki et al./Finland/2001/Not reported [49] | 159 | Probiotic = 77 Placebo = 82 |
Lactobacillus rhamnosus (GG)/1 × 1010 CFU (twice a day) | Oral capsule | From 2–4 weeks before delivery to postpartum. | Atopic sensitization | Some Concerns | Potential conflict of interest |
| Karamali et al./ Iran/2016/IRCT201601035623N63 [50] |
60 pregnant women with GDM | Probiotic = 30 Placebo = 30 |
Lactobacillus acidophilus/2 × 109 CFU Lactobacillus casei/2 × 109 CFU Bifidobcterium bifidum/2 × 109 CFU (daily) |
Oral capsule | Six weeks from 24–28 WoG | Glycemic control and lipid profile | Some Concerns | Potential conflict of interest |
| Karamali et al./ Iran/2017/IRCT201704205623N108 [51] |
60 pregnant women with GDM | Synbiotic = 30 Placebo = 30 |
Lactobacillus acidophilus (T16, IBRC-M10785)/2 × 109 CFU Lactobacillus casei (T2, IBRC-M10783)/2 × 109 CFU Bifidobacterium bifidum (T1, IBRC-M10771)/2 × 109 CFU + inulin/800 mg (daily) |
Oral capsule | Six weeks of duration (Commencement of treatment not specified) |
Inflammation and oxidative stress | Some Concerns | Potential conflict of interest |
| Kijmanawat et al./Thailand/2018/Thai Clinical Trials Registry Number 20170606002 [52] | 60 pregnant women with GDM | Probiotic = 28 Placebo = 29 |
Lactobacillus acidophilus/1 × 109 CFU Bifidobacterium bifidum/1 × 109 CFU (daily) |
Oral capsule | Four weeks from 24–28 WoG | Insulin resistance | Low | Potential conflict of interest |
| Kim et al./Korea/2009/ISRCTN26134979 [53] | 112 | Probiotic = 33 Placebo = 35 |
Bifidobacterium bifidum (BGN4)/1.6 × 109 CFU Bifidobacterium animalis (AD011)/1.6 × 109 CFU Lactobacillus acidophilus (AD031)/1.6 × 109 CFU (daily) |
Powder | From 4–8 weeks before delivery to postpartum | Eczema in offspring | Some Concerns | Existing conflict of interest |
| Kopp et al./Germany/2007/UKF000505 [54] | 105 | Probiotic = 50 Placebo = 44 |
Lactobacillus rhamnosus (GG, ATC 53013)/5 × 109 CFU (twice a day) |
Oral capsule | From 4–6 weeks before delivery to postpartum | Atopic disease in offspring | Some Concerns | Existing conflict of interest |
| Kukkonen et al./Finland/2006/Not reported [55] | 1223 | Probiotic = 461 Placebo = 464 |
Lactobacillus rhamnosus (GG, ATC 53103)/5 × 109 CFU Lactbacillus rhamnosus (LCT705, DSM 7061)/5 × 109 CFU Bifidobacterium breve (Bb99, DSM 13692)/2 × 108 CFU Propionibacterium freudenreichii shermanii (JS, DSM 7076)/2 × 109 CFU (Twice a day) |
Oral capsule | From 36 WoG to delivery | Allergic disease in offspring | Low | Existing conflict of interest |
| Laitinen et al./Finland/2008/NCT00167700 [56,57] | 256 | Diet + Probiotic = 85 Diet + Placebo = 86 Control + Placebo = 85 |
Lactobacillus rhamnosus (GG, ATCC 53103)/1 × 1010 CFU Bifidobacterium animalis (Bb-12)/1 × 1010 CFU + Dietary counseling (daily) |
Oral capsule | From 14 WoG to postpartum | Infant’s metabolic status and maternal anthropometric measures | Low | Potential conflict of interest |
| Lindsay et al./Ireland/2014/ISRCTN97241163(A) [58] | 175 obese pregnant women | Probiotic = 63 Placebo = 75 |
Lactobacillus salivarius (UCC118)/1 × 109 CFU (daily) |
Oral capsule | From 24 to 28 WoG | Glucose status | Low | No conflict of interest |
| Lindsay et al./Ireland/2015/ISRCTN97241163(B) [59] | 149 pregnant women with GDM | Probiotic = 74 Placebo = 75 |
Lactobacillus salivarius (UCC118)/1 × 109 CFU (daily) |
Oral capsule | From <34 to delivery | Metabolic parameters and pregnancy outcomes | Low | No conflict of interest |
| Mantaring et al./Philippines/2018/NCT01073033 [60] | 233 | Probiotic + food supplement = 60 Food supplement = 62 Control = 61 |
Bifiboacterium animalis (CNCC I-3446)/7 × 108 CFU Lactobacillus rhamnosus (CGMCC I-3724)/7 × 108 CFU (twice a day) |
Powder | From 24–28 WoG to postpartum | Infant’s diarrhea | Some Concerns | Existing conflict of interest |
| Mastromarino et al./Italy/2015/NCT01367470 [61,62] | 67 | Probiotic = 33 Placebo = 33 |
Lactobacillus paracasei (DSM 24733) Lactobacillus plantarum (DSM 24730) Lactobacillus acidophilus (DSM 24735) Lactobacillus delbrueckii bulgaricus (DSM 24734) Bifidobacterium longum (DSM 24736) Bifidobacterium breve (DSM 24732) Bifidobacterium infantis (DSM 24737) Streptococcus thermophilus (DSM 24731)/9 × 109 CFU total (daily) |
Powder | From 36 WoG to postpartum | Breast milk bacteria | High | No conflict of interest |
| McMillan et al./ Rwanda/2018/NCT02150655 [63] |
38 | Probiotic = 8 Placebo = 5 |
Lactobacillus rhamnosus (GR-1)/1 × 109 CFU Lactobacillus reuteri (RC-14)/1 × 109 CFU (daily) |
Oral capsule | One month from 4–32 WoG | Vaginal microbiota | High | Potential conflict of interest |
| Nabhani et al./ Iran/2018/IRCT201511183140N16 [64] |
95 pregnant women with GDM | Synbiotic = 45 Placebo = 45 |
Lactobacillus acidophilus/5 × 1010 CFU/g Lactobacillus plantarum/1.5 × 1010 CFU/g Lactobacillus fermentum/7 × 109 CFU/g Lactobacillus gasseri/2 × 1010 CFU/g + FOS/38.5 mg (500 mg daily) |
Oral capsule | Six weeks from 24–28 WoG | Insulin resistance, lipid profile and antioxidative status | Some Concerns | Potential conflict of interest |
| Niers et al./Netherlands/2009/NCT00200954 [65] | 156 | Probiotic = 50 Placebo = 52 |
Bifidobacterium bifidum (W23)/1 × 109 CFU Bifidobacterium animalis (W52)/1 × 109 CFU Lactococcus lactis (W58)/1 × 109 CFU (daily) |
Oral capsule | From the last six weeks of pregnancy to postpartum | Eczema in offspring, microbial colonization and immune response | Some Concerns | Existing conflict of interest |
| Okense-Gafa et al./New Zealand/2018/ACTRN12615000400561 [66] | 230 obese pregnant women | Probiotic = 115 Placebo = 115 |
Lactobacillus rhamnosus (GG)/7 × 109 CFU Bifidobacterium animalis (Bb-12)/7 × 109 CFU (daily) |
Oral capsule | From 12–17 WoG to delivery | Gestational weight gain and pregnancy outcomes | Low | No conflict of interest |
| Olsen et al./Australia/2017/Not reported [67] | 34 | Probiotic = 7 Control = 13 |
Lactobacillus rhamnosus (GR-1) Lactobacillus reuteri (RC-14)/1 × 108 CFU total (daily) |
Not specified | Three weeks from 36 WoG | Occurrence of streptococcus GBS | High | Potential conflict of interest |
| Ou et al./Taiwan/2012/IDNCT00325273 [68] | 191 | Probiotic = 95 Placebo = 96 |
Lactobacillus rhamnosus (GG, ATCC 53103)/1 × 1010 CFU (daily) |
Oral capsule | From 24 WoG to postpartum | Allergic disease | Some Concerns | Potential conflict of interest |
| Pellonperä et./Finland/2019/NCT01922791 [69] | 439 | Probiotic + Placebo = 110 Fish oil + Probiotic = 109 Fish oil + Placebo = 109 Placebo + Placebo = 110 |
Lactobacillus rhamnosus (HN001, ATCC SD5675)/1 × 1010 CFU Bifidobacterium animalis (420, DSM 22089)/1 × 1010 CFU (daily) |
Oral capsule | From <18 WoG to postpartum | Risk of GDM and glucose metabolism | Low | No conflict of interest |
| Sahhaf et al./ Iran/2019/IRCT20121224011862N2 [70] |
84 | Probiotic = 42 Placebo = 42 |
Lactobacillus acidophilus Bifidobacterium animalis /1 × 106 CFU total (300 mg daily) |
Yoghurt | Eight weeks from 24–28 WoG | Glycemic parameters | Some Concerns | Potential conflict of interest |
| Sharpe et al./Canada/2019/NCT02528981 [71] | 139 | Probiotic = 57 Placebo = 56 |
Lactobacillus rhamnosus (GR-1)/2.5 × 109 CFU Lactobacillus reuteri (RC-14)/2.5 × 109 CFU (twice a day) |
Oral capsule | Twelve weeks from 23–25 WoG | Occurrence of streptococcus GBS | Some Concerns | Potential conflict of interest |
| Taghizadeh et al./ Iran/2013/IRCT201212105623N3 [72] |
56 | Synbiotic = 26 Placebo = 26 |
Lactobacillus sporogenes/9 × 107 CFU + Inulin/0.36 g (twice a day) |
Not specified | Nine weeks from the third trimester of gestation | Glycemic status and C-reactive protein sensitivity | Some Concerns | Potential conflict of interest |
| Wickens et al./New Zealand/2008/ACTRN12607000518460 [73] | 512 | Probiotic 1 = 157 Probiotic 2 = 158 Placebo = 159 |
Probiotic 1 = Lactobacillus rhamnosus (HN001)/6 × 109 CFU Probiotic 2 =Bifidobacterium animalis animalis (HN019)/9 × 109 CFU (daily) |
Oral capsule | From 35 WoG to postpartum | Eczema and atopic sensitization in offspring | Low | Existing conflict of interest |
| Wickens et al./New Zealand/2017/ACTRN12612000196842 [74] | 423 | Probiotic = 206 Placebo = 202 |
Lactobacillus rhamnosus (HN001)/6 × 109 CFU (daily) |
Oral capsule | From 14–16 WoG to postpartum | Occurrence of streptococcus GBS | Some Concerns | No conflict of interest |
| Yang et al./Canada/2020/NCT01697683 [75] | 86 | Probiotic = 41 Placebo = 43 |
Lactobacillus rhamnosus (GR-1)/2.5 × 109 CFU Lactobacillus reuteri (RC-14)/2.5 × 109 CFU (daily) |
Oral capsule | Twelve weeks from 12–16 WoG | Vaginal microbiota, chemokines and cytokines profile | High | Potential conflict of interest |
CFU: Colony-Forming Unit; GBS: Group B Streptococcus; GDM: Gestational Diabetes Mellitus; FOS: Fructooligosaccharide. WoG: Week of Gestation.