Gap finder

Search review questions

Each row is one question a systematic review asked: who, what, compared with what, and which outcome, with the effect it found and how certain that is. Words match anywhere in the field.

Limit to evidence status or GRADE (optional)

3,601 questions in 252 reviews · Pregnancy and Childbirth

current versions
No studies 726 · 20.2%Ungraded 421 · 11.7%Very low 828 · 23%Low 993 · 27.6%Moderate 486 · 13.5%High 147 · 4.1%

Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.

QuestionEffectEvidenceStatus / GRADE
Pneumococcal vaccine vs control vaccine
Pneumococcal colonization ‐ By 6‐7 months of age · Pregnant women undergoing vaccination to prevent infant infection
Pneumococcal vaccination during pregnancy for preventing infant infection (2015) · Cochrane
RR 0.67 [0.22, 2.08]2 studies · 148 participantsLow
Routine fetal movement counting vs mixed or undefined fetal movement counting
Perinatal death and or severe morbidity (neonatal intensive care unit admission, neonatal encephalopathy) · Pregnant women who had reached the gestational age of fetal viability
Fetal movement counting for assessment of fetal wellbeing (2015) · Cochrane
no estimate extractedNRNo studies
Routine fetal movement counting vs mixed or undefined fetal movement counting
Caesarean section · Pregnant women who had reached the gestational age of fetal viability
Fetal movement counting for assessment of fetal wellbeing (2015) · Cochrane
RR 0.93 [0.6, 1.44]1 study · 1076 participantsLow
Routine fetal movement counting vs mixed or undefined fetal movement counting
Perinatal death · Pregnant women who had reached the gestational age of fetal viability
Fetal movement counting for assessment of fetal wellbeing (2015) · Cochrane
no estimate extracted1 study · 1076 participantsLow
Routine fetal movement counting vs mixed or undefined fetal movement counting
Maternal anxiety · Pregnant women who had reached the gestational age of fetal viability
Fetal movement counting for assessment of fetal wellbeing (2015) · Cochrane
no estimate extracted1 study · 1013 participantsModerate
Routine fetal movement counting vs mixed or undefined fetal movement counting
Maternal‐fetal attachment · Pregnant women who had reached the gestational age of fetal viability
Fetal movement counting for assessment of fetal wellbeing (2015) · Cochrane
no estimate extracted1 study · 951 participantsLow
Routine fetal movement counting vs mixed or undefined fetal movement counting
Antenatal hospital admission rate per cluster (mean) · Pregnant women who had reached the gestational age of fetal viability
Fetal movement counting for assessment of fetal wellbeing (2015) · Cochrane
SMD 0.381 study · 52 participantsLow
Routine fetal movement counting vs mixed or undefined fetal movement counting
Low birthweight (< 2500 g or < 10th centile) · Pregnant women who had reached the gestational age of fetal viability
Fetal movement counting for assessment of fetal wellbeing (2015) · Cochrane
RR 0.98 [0.66, 1.44]1 study · 1073 participantsLow
Specialised antenatal clinics vs standard care
Perinatal death · Women with a multiple pregnancy for improving maternal and infant outcomes
Specialised antenatal clinics for women with a multiple pregnancy for improving maternal and infant outcomes (2015) · Cochrane
RR 1.02 [0.26, 4.03]1 study · 324 participantsVery low
Specialised antenatal clinics vs standard care
Caesarean birth · Women with a multiple pregnancy for improving maternal and infant outcomes
Specialised antenatal clinics for women with a multiple pregnancy for improving maternal and infant outcomes (2015) · Cochrane
RR 1.38 [1.06, 1.81]1 study · 162 participantsModerate
Specialised antenatal clinics vs standard care
Postnatal depression (6 months' postpartum). EPDS score 13 or more. · Women with a multiple pregnancy for improving maternal and infant outcomes
Specialised antenatal clinics for women with a multiple pregnancy for improving maternal and infant outcomes (2015) · Cochrane
RR 0.48 [0.19, 1.2]1 study · 133 participantsVery low
Specialised antenatal clinics vs standard care
Breastfeeding 6 months' postpartum · Women with a multiple pregnancy for improving maternal and infant outcomes
Specialised antenatal clinics for women with a multiple pregnancy for improving maternal and infant outcomes (2015) · Cochrane
RR 0.63 [0.24, 1.68]1 study · 123 participantsVery low
Specialised antenatal clinics vs standard care
Small‐for‐gestational age · Women with a multiple pregnancy for improving maternal and infant outcomes
Specialised antenatal clinics for women with a multiple pregnancy for improving maternal and infant outcomes (2015) · Cochrane
no estimate extractedNRNo studies
Specialised antenatal clinics vs standard care
Very preterm birth (defined as birth less than 34 weeks' gestation) · Women with a multiple pregnancy for improving maternal and infant outcomes
Specialised antenatal clinics for women with a multiple pregnancy for improving maternal and infant outcomes (2015) · Cochrane
no estimate extractedNRNo studies
Brochure and an audiotape vs standard care
Rate of toxoplasmosis seroconversion in pregnant women · women of reproductive age, irrespective of their pregnant status
Prenatal education for congenital toxoplasmosis (2015) · Cochrane
RR 1.7 [0.56, 5.21]1 study · 3949 participantsLow
Brochure and an audiotape vs standard care
Pregnant women behavior with respect to the avoidance of risk factors for toxoplasmosis infection during pregnancy (no consumption of uncooked meat of any type) · women of reproductive age, irrespective of their pregnant status
Prenatal education for congenital toxoplasmosis (2015) · Cochrane
OR 1.21 [0.98, 1.5]1 study · 1 participantsModerate
Brochure and an audiotape vs standard care
Pregnant women behavior with respect to the avoidance of risk factors for toxoplasmosis during pregnancy (hand washing after contact with transmission factor and before meals) · women of reproductive age, irrespective of their pregnant status
Prenatal education for congenital toxoplasmosis (2015) · Cochrane
OR 1.01 [0.38, 1.22]1 study · 1 participantsLow
Brochure and an audiotape vs standard care
Rate of congenital toxoplasmosis defined by persistence of IgG antibodies beyond 11 months · women of reproductive age, irrespective of their pregnant status
Prenatal education for congenital toxoplasmosis (2015) · Cochrane
no estimate extractedNRNo studies
Brochure and an audiotape vs standard care
Pregnant women knowledge of risk factors for acquiring toxoplasmosis infection as objectively measured through specific questionnaire · women of reproductive age, irrespective of their pregnant status
Prenatal education for congenital toxoplasmosis (2015) · Cochrane
no estimate extractedNRNo studies
Brochure and an audiotape vs standard care
Pregnant women awareness of the importance of avoiding toxoplasmosis infection during pregnancy as objectively measured through specific questionnaire · women of reproductive age, irrespective of their pregnant status
Prenatal education for congenital toxoplasmosis (2015) · Cochrane
no estimate extractedNRNo studies
Lower genital tract infection screening vs no screening
Preterm birth less than 37 weeks · pregnant women presenting for routine prenatal care
Antenatal lower genital tract infection screening and treatment programs for preventing preterm delivery (2015) · Cochrane
RR 0.55 [0.41, 0.75]1 study · 4155 participantsModerate
Lower genital tract infection screening vs no screening
Preterm low birthweight (below or equal 2500 g) · pregnant women presenting for routine prenatal care
Antenatal lower genital tract infection screening and treatment programs for preventing preterm delivery (2015) · Cochrane
RR 0.48 [0.34, 0.66]1 study · 4155 participantsModerate
Lower genital tract infection screening vs no screening
Preterm very low birthweight (below or equal 1500 g) · pregnant women presenting for routine prenatal care
Antenatal lower genital tract infection screening and treatment programs for preventing preterm delivery (2015) · Cochrane
RR 0.34 [0.15, 0.75]1 study · 4155 participantsModerate
Planned caesarean section vs planned vaginal birth
Maternal death or serious maternal morbidity · women with a twin pregnancy
Planned caesarean section for women with a twin pregnancy (2015) · Cochrane
RR 0.86 [0.67, 1.11]2 studies · 2844 participantsModerate
Planned caesarean section vs planned vaginal birth
Perinatal or neonatal death or serious neonatal morbidity · women with a twin pregnancy
Planned caesarean section for women with a twin pregnancy (2015) · Cochrane
RR 1.15 [0.8, 1.67]1 study · 5565 participantsModerate
Planned caesarean section vs planned vaginal birth
Disability in childhood · women with a twin pregnancy
Planned caesarean section for women with a twin pregnancy (2015) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Planned caesarean section vs planned vaginal birth
Perinatal or neonatal death · women with a twin pregnancy
Planned caesarean section for women with a twin pregnancy (2015) · Cochrane
RR 1.41 [0.76, 2.62]2 studies · 5685 participantsModerate
Planned caesarean section vs planned vaginal birth
Serious neonatal morbidity · women with a twin pregnancy
Planned caesarean section for women with a twin pregnancy (2015) · Cochrane
RR 1.03 [0.65, 1.64]2 studies · 5644 participantsModerate
Planned caesarean section vs planned vaginal birth
Longer‐term maternal outcomes: failure to breastfeed · women with a twin pregnancy
Planned caesarean section for women with a twin pregnancy (2015) · Cochrane
RR 1.14 [0.95, 1.38]1 study · 2570 participantsModerate
Planned caesarean section vs planned vaginal birth
Longer‐term maternal outcomes: postnatal depression, as defined by trial authors (EPDS > 12) · women with a twin pregnancy
Planned caesarean section for women with a twin pregnancy (2015) · Cochrane
RR 0.95 [0.78, 1.14]1 study · 2570 participantsModerate
Caffeinated (experimental group) vs decaffeinated group (control group)
Birthweight (g) · Pregnant women recruited before 20 weeks' gestation
Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcomes (2015) · Cochrane
MD 201 study · 1197 participantsLow
Caffeinated (experimental group) vs decaffeinated group (control group)
Preterm birth · Pregnant women recruited before 20 weeks' gestation
Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcomes (2015) · Cochrane
RR 0.81 [0.48, 1.37]1 study · 1153 participantsLow
Caffeinated (experimental group) vs decaffeinated group (control group)
Low birthweight · Pregnant women recruited before 20 weeks' gestation
Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcomes (2015) · Cochrane
no estimate extractedNRNo studies
Caffeinated (experimental group) vs decaffeinated group (control group)
Perinatal mortality rate · Pregnant women recruited before 20 weeks' gestation
Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcomes (2015) · Cochrane
no estimate extractedNRNo studies
Caffeinated (experimental group) vs decaffeinated group (control group)
Sudden infant death syndrome · Pregnant women recruited before 20 weeks' gestation
Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcomes (2015) · Cochrane
no estimate extractedNRNo studies
Caffeinated (experimental group) vs decaffeinated group (control group)
Gestational diabetes · Pregnant women recruited before 20 weeks' gestation
Effects of restricted caffeine intake by mother on fetal, neonatal and pregnancy outcomes (2015) · Cochrane
no estimate extractedNRNo studies
Routine/revealed vs selective/concealed ultrasound
Detection of fetal abnormality before 24 weeks' gestation · Pregnant women at less than 24 weeks' gestation undergoing fetal assessment by ultrasound
Ultrasound for fetal assessment in early pregnancy (2015) · Cochrane
RR 3.46 [1.67, 7.14]2 studies · 387 participantsModerate
Routine/revealed vs selective/concealed ultrasound
Detection of multiple pregnancy by 24 to 26 weeks' gestation (number NOT detected) · Pregnant women at less than 24 weeks' gestation undergoing fetal assessment by ultrasound
Ultrasound for fetal assessment in early pregnancy (2015) · Cochrane
RR 0.07 [0.03, 0.17]7 studies · 295 participantsModerate
Routine/revealed vs selective/concealed ultrasound
Induction of labour for 'post‐term' pregnancy · Pregnant women at less than 24 weeks' gestation undergoing fetal assessment by ultrasound
Ultrasound for fetal assessment in early pregnancy (2015) · Cochrane
RR 0.59 [0.42, 0.83]8 studies · 25516 participantsLow
Routine/revealed vs selective/concealed ultrasound
Perinatal death (all babies) · Pregnant women at less than 24 weeks' gestation undergoing fetal assessment by ultrasound
Ultrasound for fetal assessment in early pregnancy (2015) · Cochrane
RR 0.89 [0.7, 1.12]10 studies · 35735 participantsLow
Calcium supplementation vs placebo or no treatment (maternal outcomes)
Preterm birth (a) Birth prior to 37 weeks · healthy pregnant women receiving calcium supplementation vs placebo or no treatment
Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and… (2015) · Cochrane
RR 0.86 [0.7, 1.05]13 studies · 16139 participantsModerate
Calcium supplementation vs placebo or no treatment (maternal outcomes)
Preterm birth (b) Birth prior to 34 weeks · healthy pregnant women receiving calcium supplementation vs placebo or no treatment
Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and… (2015) · Cochrane
RR 1.04 [0.8, 1.36]4 studies · 5669 participantsModerate
Calcium supplementation vs placebo or no treatment (maternal outcomes)
Low birthweight (< 2500 g) · healthy pregnant women receiving calcium supplementation vs placebo or no treatment
Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and… (2015) · Cochrane
RR 0.93 [0.81, 1.07]6 studies · 14162 participantsModerate
All diet and/or exercise interventions vs standard/other care
Excessive weight gain · pregnant women
Diet or exercise, or both, for preventing excessive weight gain in pregnancy (2015) · Cochrane
RR 0.8 [0.73, 0.87]24 studies · 7096 participantsHigh
All diet and/or exercise interventions vs standard/other care
Mean GWG (kg) · pregnant women
Diet or exercise, or both, for preventing excessive weight gain in pregnancy (2015) · Cochrane
no estimate extractedNRNo studies
All diet and/or exercise interventions vs standard/other care
Low weight gain · pregnant women
Diet or exercise, or both, for preventing excessive weight gain in pregnancy (2015) · Cochrane
RR 1.14 [1.02, 1.27]11 studies · 4422 participantsModerate
All diet and/or exercise interventions vs standard/other care
Preterm birth · pregnant women
Diet or exercise, or both, for preventing excessive weight gain in pregnancy (2015) · Cochrane
RR 0.91 [0.68, 1.22]16 studies · 5923 participantsModerate
All diet and/or exercise interventions vs standard/other care
Pre‐eclampsia · pregnant women
Diet or exercise, or both, for preventing excessive weight gain in pregnancy (2015) · Cochrane
RR 0.95 [0.77, 1.16]15 studies · 5330 participantsHigh
All diet and/or exercise interventions vs standard/other care
Caesarean delivery · pregnant women
Diet or exercise, or both, for preventing excessive weight gain in pregnancy (2015) · Cochrane
RR 0.95 [0.88, 1.03]28 studies · 7534 participantsHigh
All diet and/or exercise interventions vs standard/other care
Macrosomia Infant birthweight > 4000 g · pregnant women
Diet or exercise, or both, for preventing excessive weight gain in pregnancy (2015) · Cochrane
RR 0.93 [0.86, 1.02]27 studies · 8598 participantsHigh