Condition

Pregnancy and Delivery Health

Pregnancy sharply raises the body's need for nutrients, because a growing baby draws on them to form its organs. Vitamin D and iron have the most support: a meta-analysis found pre-eclampsia became less common with vitamin D, and iron raised ferritin, a measure of the body's iron stores. Ferritin is only a marker, though, and folic acid's effect on birth weight was mixed.

Sources: PMID 39716171

Supplements studied: 16
Medicines and peptides: 1
Graded outcomes: 19
Trials: 14
People studied: 635,200

Evidence by supplement

Strong
Moderate
Limited
Very limited

16 supplements

Vitamin D

Vitamin D: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Pre-Eclampsia Risk Moderate Improvement	Improves (the measure goes down)	Moderate effect	1 study	5,035 people
Studies that measured pre-eclampsia risk Efficacy of vitamin D supplementation on the incidence of preeclampsia: a systematic review and meta-analysis.BMC Pregnancy Childbirth · PMID 39716171
	Preterm Birth Risk	Changes; see studies			6,055 people

Peppermint

Peppermint: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Nausea Symptoms Small Improvement	Improves (the measure goes down)	Small effect	4 studies	1,157 people
Studies that measured nausea symptoms Examination of the effectiveness of peppermint aromatherapy on nausea in women post C-sectionJ Holist Nurs · PMID 22034523 Peppermint oil: a treatment for postoperative nauseaJ Adv Nurs · PMID 9378876 An investigation into the use of aromatherapy in intrapartum midwifery practiceJ Altern Complement Med · PMID 10784271 and 1 more on the Peppermint page
	Nipple Cracks	Improves (the measure goes up)		2 studies	72 people
Studies that measured nipple cracks A randomized trial of peppermint gel, lanolin ointment, and placebo gel to prevent nipple crack in primiparous breastfeeding womenMed Sci Monit · PMID 17767120 Effect of peppermint water on prevention of nipple cracks in lactating primiparous women: a randomized controlled trialInt Breastfeed J · PMID 17442122
	Sedation	Improves (the measure goes up)			35 people

Folic Acid (Vitamin B9)

Infant Birth Weight
Infant Death Risk: improves

Folic Acid (Vitamin B9): outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Studies	People
	Infant Birth Weight Mixed effect		2 studies	707 people
Studies that measured infant birth weight Effect of folate intake on health outcomes in pregnancy: a systematic review and meta-analysis on birth weight, placental weight and length of gestation.Nutr J · PMID 22992251 Folic acid supplementation in pregnancy to prevent preterm birth: a systematic review and meta-analysis of randomized controlled trials.Eur J Obstet Gynecol Reprod Biol · PMID 26901401
	Infant Death Risk	Improves (the measure goes down)		4,002 people

Iron

Ferritin: improves
Hemoglobin: improves
Infant Birth Weight: improves

Iron: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Ferritin Moderate Increase	Improves (the measure goes up)	Moderate effect		3,648 people
	Hemoglobin	Improves (the measure goes up)		7 studies	4,421 people
Studies that measured hemoglobin Role of iron in the reduction of anemia among women of reproductive age in low-middle income countries: insights from systematic review and meta-analysis.BMC Womens Health · PMID 37069552 Oral iron supplementation and anaemia in children according to schedule, duration, dose and cosupplementation: a systematic review and meta-analysis of 129 randomised trials.BMJ Glob Health · PMID 36849195 Efficacy of daily versus intermittent oral iron supplementation for prevention of anaemia among pregnant women: a systematic review and meta-analysis.EClinicalMedicine · PMID 39114275 and 4 more on the Iron page
	Infant Birth Weight	Improves (the measure goes down)		1 study	361 people
Studies that measured infant birth weight Iron supplements in pregnant women with normal iron status: A systematic review and meta-analysis.Acta Obstet Gynecol Scand · PMID 37403900
	Iron Deficiency Anemia Risk	Changes; see studies			1,670 people
	Iron Deficiency Risk	Changes; see studies			1,663 people

Evening Primrose Oil

Cervix Readiness (Pregnancy): improves
Infant Birth Weight
Labor Duration (Pregnancy): changes; see studies

Evening Primrose Oil: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Cervix Readiness (Pregnancy) Small Increase	Improves (the measure goes up)	Small effect		652 people
	Infant Birth Weight No effect		NoneNo effect		179 people
	Labor Duration (Pregnancy)	Changes; see studies		2 studies	341 people
Studies that measured labor duration (pregnancy) The effect of evening primrose oil on cervical ripening and birth outcomes: A systematic review and meta-analysis.Heliyon · PMID 36846678 Evening primrose oil for cervical ripening in term pregnancies: a systematic review and meta-analysis.J Complement Integr Med · PMID 34261202

Saffron

Cervix Readiness (Pregnancy): improves
Hemoglobin: improves
Hematocrit: improves

Saffron: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Cervix Readiness (Pregnancy) Moderate Increase	Improves (the measure goes up)	Moderate effect	1 study	50 people
Studies that measured cervix readiness (pregnancy) Effect of Saffron (Fan Hong Hua) On the Readiness of The Uterine Cervix In Term Pregnancy: A Placebo-Controlled Randomized TrialIran Red Crescent Med J · PMID 28180016
	Hemoglobin	Improves (the measure goes up)		1 study	50 people
Studies that measured hemoglobin Safety evaluation of saffron (Crocus sativus) tablets in healthy volunteersPhytomedicine · PMID 18693099
	Hematocrit	Improves (the measure goes up)			50 people
	Labor Duration (Pregnancy)	Changes; see studies			50 people
	Uterine Contractions Onset	Improves (the measure goes up)			50 people
	Vaginal Delivery Rate	Improves (the measure goes up)			50 people

Chlorella

Anemia Risk: improves
Blood Pressure: improves
Leg Edema: changes; see studies

Chlorella: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Anemia Risk Small Improvement	Improves (the measure goes down)	Small effect	1 study	70 people
Studies that measured anemia risk Chlorella pyrenoidosa supplementation reduces the risk of anemia, proteinuria and edema in pregnant womenPlant Foods Hum Nutr · PMID 20013055
	Blood Pressure	Improves (the measure goes down)		3 studies	736 people
Studies that measured blood pressure Effect of Chlorella supplementation on cardiovascular risk factors: A meta-analysis of randomized controlled trialsClin Nutr · PMID 29037431 Anti-hypertensive effect of gamma-aminobutyric acid (GABA)-rich Chlorella on high-normal blood pressure and borderline hypertension in placebo-controlled double blind studyClin Exp Hypertens · PMID 19811362 Quantifying the Impact of Algae Supplement on Blood Pressure: Systematic Review and Meta-analysis of Randomized Controlled Trials.Curr Probl Cardiol · PMID 35870546
	Leg Edema	Changes; see studies			70 people
	Proteinuria	Improves (the measure goes up)			70 people

Yarrow

Inflammation: improves
Pain: improves
Wound Healing: improves

Yarrow: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Inflammation Small Decrease	Improves (the measure goes down)	Small effect		140 people
	Pain	Improves (the measure goes down)		1 study	140 people
Studies that measured pain The effect of Achillea millefolium and Hypericum perforatum ointments on episiotomy wound healing in primiparous women.J Matern Fetal Neonatal Med · PMID 28027682
	Wound Healing	Improves (the measure goes up)		1 study	140 people
Studies that measured wound healing The efficacy of Achilles millefolium topical gel along with intralesional injection of glucantime in the treatment of acute cutaneous leishmaniasis major.Adv Biomed Res · PMID 24804185
	Vaginal Irritation	Improves (the measure goes up)			140 people

Magnesium

Cramps
Pregnancy Complications: improves
Pre-Eclampsia Risk: changes; see studies

Magnesium: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Cramps No effect		NoneNo effect	8 studies	38 people
Studies that measured cramps Magnesium for skeletal muscle crampsCochrane Database Syst Rev · PMID 32956536 Does oral magnesium substitution relieve pregnancy-induced leg crampsEur J Obstet Gynecol Reprod Biol · PMID 18768245 The effect of magnesium infusion on rest cramps: randomized controlled trial.J Gerontol A Biol Sci Med Sci · PMID 21289017 and 5 more on the Magnesium page
	Pregnancy Complications	Improves (the measure goes up)		3 studies	1,158 people
Studies that measured pregnancy complications Magnesium supplementation in pregnancy.Cochrane Database Syst Rev · PMID 24696187 [Magnesium substitution in pregnancy. A prospective, randomized double-blind study].Geburtshilfe Frauenheilkd · PMID 3063587 BRAzil magnesium (BRAMAG) trial: a double-masked randomized clinical trial of oral magnesium supplementation in pregnancyBMC Pregnancy Childbirth · PMID 32316938
	Pre-Eclampsia Risk	Changes; see studies		2 studies	1,042 people
Studies that measured pre-eclampsia risk Oral Magnesium Supplementation for the Prevention of Preeclampsia: a Meta-analysis or Randomized Controlled Trials.Biol Trace Elem Res · PMID 34775542 Magnesium supplementation and preeclampsia in low-income pregnant women - a randomized double-blind clinical trial.BMC Pregnancy Childbirth · PMID 32272914
	Infant Death Risk	Improves (the measure goes down)		1 study	5,903 people
Studies that measured infant death risk Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis.PLoS Med · PMID 31809499
	Infant Birth Weight	Improves (the measure goes down)			5,577 people

Calcium

All-Cause Mortality
Pre-Eclampsia Risk: changes; see studies
Infant Birth Weight: changes; see studies

Calcium: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	All-Cause Mortality No effect		NoneNo effect	1 study	30,945 people
Studies that measured all-cause mortality Association Between Calcium Supplementation and the Risk of Cardiovascular Disease and Stroke: A Systematic Review and Meta-Analysis.Heart Lung Circ · PMID 37743221
	Pre-Eclampsia Risk	Changes; see studies		4 studies	27,442 people
Studies that measured pre-eclampsia risk World Health Organization randomized trial of calcium supplementation among low calcium intake pregnant womenAm J Obstet Gynecol · PMID 16522392 Calcium supplementation during pregnancy for preventing hypertensive disorders and related problemsCochrane Database Syst Rev · PMID 24960615 Risk factors associated with preeclampsia in healthy nulliparous women. The Calcium for Preeclampsia Prevention (CPEP) Study GroupAm J Obstet Gynecol · PMID 9396883 and 1 more on the Calcium page
	Infant Birth Weight	Changes; see studies		2 studies	14,162 people
Studies that measured infant birth weight Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and infant outcomes.Cochrane Database Syst Rev · PMID 25922862 Effects of Maternal Nutritional Supplements and Dietary Interventions on Placental Complications: An Umbrella Review, Meta-Analysis and Evidence MapNutrients · PMID 33573262
	Preterm Birth Risk	Improves (the measure goes down)			16,139 people

Omega-3 Fatty Acids

Blood glucose
Infant Death Risk: improves
Interleukin 6: improves

Omega-3 Fatty Acids: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Blood glucose No effect		NoneNo effect	1 study	1 person
Studies that measured blood glucose The effect of omega-3 supplementation on metabolic, inflammatory and oxidative stress biomarkers in pregnant women: a systematic review and meta-analysis.Front Nutr · PMID 41058996
	Infant Death Risk	Improves (the measure goes down)		1 study	16,066 people
Studies that measured infant death risk Supplementation of Omega 3 during Pregnancy and the Risk of Preterm Birth: A Systematic Review and Meta-Analysis.Nutrients · PMID 34069867
	Interleukin 6	Improves (the measure goes down)		1 study	1 person
Studies that measured interleukin 6 Effect of omega-3 fatty acid supplementation on markers of inflammation and endothelial function in patients with chronic heart disease: A systematic review and meta-analysis.Cell Mol Biol · PMID 38836663
	Total Antioxidant Capacity (TAC)	Improves (the measure goes up)		1 study	1 person
Studies that measured total antioxidant capacity (tac) The effects of ω-3 fatty acids on inflammatory and oxidative stress markers in patients with Type 2 diabetes mellitus: A systematic review and meta-analysis of controlled trials.Prostaglandins Other Lipid Mediat · PMID 39243880
	Total cholesterol	Improves (the measure goes down)		1 study	1 person
Studies that measured total cholesterol Effect of omega-3 supplementation on lipid profile in children and adolescents: a systematic review and meta-analysis of randomized clinical trials.Nutr J · PMID 36765362
	C-Reactive Protein (CRP)	Improves (the measure goes down)			1 person
	High-density lipoprotein (HDL)	Improves (the measure goes up)			1 person
	Insulin	Changes; see studies			1 person
	Low-density lipoprotein (LDL)	Improves (the measure goes down)			1 person
	Oxidative Stress Biomarkers	Improves (the measure goes down)			1 person
	Pregnancy Complications	Improves (the measure goes up)			17,156 people
	Triglycerides	Improves (the measure goes down)			1 person

Zinc

Infant Birth Weight
Preterm Birth Risk: changes; see studies

Zinc: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People
	Infant Birth Weight No effect		NoneNo effect		6,757 people
	Preterm Birth Risk	Changes; see studies		1 study	7,637 people
Studies that measured preterm birth risk Zinc supplementation for improving pregnancy and infant outcome.Cochrane Database Syst Rev · PMID 33724446

Prenatal Vitamins

Anemia Risk
Infant Birth Weight: improves
Executive Function: improves

Prenatal Vitamins: outcomes studied for Pregnancy and Delivery Health
Outcome	Effect	Size	Studies	People
Anemia Risk No effect		NoneNo effect		75,051 people
Infant Birth Weight	Improves (the measure goes down)		2 studies	2,727 people
Executive Function	Improves (the measure goes up)			439,649 people
Infant Growth	Improves (the measure goes up)			17,257 people
Iron Deficiency Anemia Risk	Changes; see studies			15,540 people
Iron Deficiency Risk	Changes; see studies			15,540 people

Docosahexaenoic Acid

Cognition of Offspring
Infant Birth Weight: improves
Postpartum Depression Symptoms: improves

Docosahexaenoic Acid: outcomes studied for Pregnancy and Delivery Health
Outcome	Effect	Size	Studies	People
Cognition of Offspring No effect		NoneNo effect		2,320 people
Infant Birth Weight	Improves (the measure goes down)		1 study	5,710 people
Postpartum Depression Symptoms	Improves (the measure goes down)		1 study	2,320 people

Ginger (Zingiber officinale)

Nausea Symptoms: changes; see studies

Ginger (Zingiber officinale): outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Nausea Symptoms	Changes; see studies		9 studies	206 people

Probiotics

Gestational Diabetes Risk: changes; see studies

Probiotics: outcomes studied for Pregnancy and Delivery Health
Grade	Outcome	Effect	Size	Studies	People	Studies list
	Gestational Diabetes Risk	Changes; see studies		1 study	3,527 people

Prescription medicines and peptides studied, for context

These are not supplements. Most need a prescription, and some are research compounds with no approved use. They are listed so the supplement evidence above can be read against them.

1 medicine or peptide

Oxytocin (Pitocin)

Postpartum Hemorrhage Prevention: changes; see studies
Labor Duration: improves
Vaginal Delivery Success: improves

Oxytocin (Pitocin): outcomes studied for Pregnancy and Delivery Health
Outcome	Effect	Size	Studies
Postpartum Hemorrhage Prevention Standard of care for PPH prophylaxis. High-dose protocols associated with lower PPH rates (7.6% vs 9.9%, RR 0.78).	Changes; see studies	Large effect	19 studies
Labor Duration Reduces induction-to-delivery interval. High-dose vs low-dose shows shorter labor with high-dose regimens.	Improves (the measure goes down)	Moderate effect	18 studies
Vaginal Delivery Success Cochrane: 91.6% vaginal delivery within 24h vs 46.2% expectant management (RR 0.16 for failure). Effective labor induction agent.	Improves (the measure goes up)	Large effect	12 studies
Cesarean Rate No significant difference in cesarean rates between high and low-dose protocols (~26-28%). Safe for labor management.	Improves (the measure goes down)	Small effect	12 studies

Key findings

Pre-Eclampsia RiskVitamin DImproves (the measure goes down)
Nausea SymptomsPeppermintImproves (the measure goes down)
Infant Birth WeightFolic Acid (Vitamin B9)

The Pregnancy & Prenatal Health protocol

2 primary supplements · 2 supporting supplements

Folate/Folic Acid400–800 mcg daily (start before conception)
Vitamin D2,000–4,000 IU daily

See the full protocol

Studies cited

1 study from PubMed

Effects of mindfulness-based interventions on mental health among women with fetal loss: A systematic review and meta-analysis.Midwifery · PMID 40701042

Evidence by supplement

Prescription medicines and peptides studied, for context

Key findings

The Pregnancy & Prenatal Health protocol

Studies cited

Related conditions

Supplement stack for Pregnancy and Delivery Health