Is it safe to eat pineapple during pregnancy?

As far as the evidence goes, yes, and the evidence is thin. We found no peer-reviewed randomized trial of pineapple in pregnant women. The warning that it brings on miscarriage or labor is folklore, and it has been tested only in laboratory tissue and rats. In pregnant rats given unripe pineapple juice daily at up to 1,000 mg per kg of body weight, there were no fetal deaths and no bleeding. The one study in women, a Nigerian retrospective cohort of 2,400, found no difference in birth weight, Apgar scores or newborn intensive care between babies of mothers who did and did not eat pineapple late in pregnancy, and that is a weak design with self-reported eating. No study in women has looked at pineapple in early pregnancy or at miscarriage.

Unsettled. The labor folklore has a laboratory basis and nothing more. A water fraction of pineapple extract made strips of pregnant rat and human uterine muscle contract in a dish. When pregnant rats were given the same fraction by mouth, their uterus did not contract during pregnancy. The ripe fraction raised uterine activity only after birth. Unripe pineapple, the form folk use names, had no effect in pregnancy or after birth. Nobody has tested this in pregnant women.

Bishop score on admission in labor, mean points

The Bishop score rates how ready the cervix is for labor, and higher means more ready. The study reports standard deviations of 1.3 and 1.5 around these means, so the two groups overlap heavily, and no confidence interval is drawn. This is an observational comparison and cannot show that pineapple caused the difference. Source: card ev-pinpg-01 below.

What the trials found

The one study in pregnant women

In a Nigerian retrospective cohort of 2,400 women who gave birth between 2018 and 2023, those who said they ate pineapple regularly in the third trimester arrived in labor with a higher Bishop score, 6.2 against 5.4. Eating was self-reported for the last 4 to 8 weeks before birth, the participant counts in the paper do not add up, and other differences between the groups may explain the gap. The authors say themselves that a retrospective study cannot establish cause and effect. Their babies did not differ in birth weight, Apgar scores or admission to neonatal intensive care. The study collected nothing on early pregnancy or miscarriage.

Bromelain, the pineapple enzymes

The worry about pineapple usually names bromelain. Every trial of bromelain we found tested capsules in adults who were not pregnant. A 2023 systematic review of 7 randomized trials found its effect on blood markers of inflammation inconsistent. Those trials used 99.9 to 1,200 mg a day for 3 to 16 weeks. We found no study that measured how much bromelain a serving of fruit delivers, so the trial doses cannot be compared with a bowl of pineapple.

A 2023 meta-analysis of oral bromelain found pain scores fell slightly more than with control treatment, a mean difference of -0.27 points (95% CI -0.45 to -0.08) across 9 studies, none of them in pregnancy. That is a small effect, and it tells us nothing about the uterus.

Rats and laboratory dishes

The rat juice study gave unripe pineapple juice at 250, 500 or 1,000 mg per kg on days 7 to 14 of pregnancy and found no change in live fetuses, implantation or resorption. The uterine muscle study used extract concentrations in an organ bath, which is not what reaches the uterus after a meal. The oral rat study used doses of grams per 3.5 oz (100 g) of body weight, far beyond anything eaten as fruit, and still saw no contraction during pregnancy.

Who should be careful

Not for everyone. Bromelain supplements are the product with an open question. The US National Center for Complementary and Integrative Health says little is known about whether bromelain is safe during pregnancy or while breastfeeding. That statement is about supplements. It does not cover fruit eaten as food.

If you take warfarin, a 2026 randomized trial of 1,500 mg of bromelain a day in 60 patients after skin surgery excluded warfarin users because of a possible contraindication. It excluded people allergic to pineapple too. No interaction was measured, and the trial used capsules rather than fruit. If you are on an anticoagulant in pregnancy, any bromelain supplement is a question for the person treating you.

For the fruit itself, the only human data on babies are the null findings from the Nigerian cohort above. That is an absence of a signal in a weak study, and it is all there is.

What expert bodies say

The NCCIH statement on bromelain supplements is the only agency position we found. We looked for a statement from ACOG or the RCOG on pineapple in pregnancy and found none.

How we searched

Searched: a local copy of the PubMed baseline for pineapple, bromelain or Ananas comosus with pregnancy, labor, uterus, miscarriage or abortion terms (5 records, none relevant). Bromelain in randomized trials and meta-analyses (17). Europe PMC for the same pineapple and pregnancy terms in the abstract (49 records, 6 relevant) and for pineapple with cervix or labor induction terms (554, one relevant). ClinicalTrials.gov (one trial of pineapple juice and a painkiller, not in pregnancy). A drug label interaction database (no bromelain passage). The NCCIH bromelain page. Search run on 7 October 2026, with a retraction check on every included paper (none retracted).

Included: one retrospective cohort in pregnant women, one rat study, two studies of uterine muscle in the laboratory and in rats, one systematic review and one meta-analysis of bromelain supplements, one randomized trial whose exclusion criteria matter here, and the NCCIH statement.

Excluded: an Iranian randomized trial of pineapple at term, which exists only as a 2023 preprint that has not been peer reviewed. A laboratory study in which another pineapple fraction relaxed uterine muscle, the opposite direction, which adds nothing beyond the rat studies above. A Cochrane review on breast engorgement whose enzyme product is not identified as bromelain. Surveys of food taboos, which record beliefs and not effects.

What we read: the full text of the Nigerian cohort. Abstracts for the other studies, each confirmed word for word by a second, independent request. The NCCIH page itself.

What we could not get: any peer-reviewed trial of pineapple on miscarriage, preterm labor or labor induction in women, and any study linking the bromelain in a serving of fruit to an effect on the uterus. We found none.

What would change this answer

A peer-reviewed version of the Iranian preprint, or any randomized trial of pineapple at term, measuring cervical readiness and the start of labor.
A prospective cohort recording pineapple intake in early pregnancy and following miscarriage. The Nigerian study looked only at labor and birth.
A measurement of bromelain in ordinary servings of fresh pineapple, so the capsule doses could be put on the same scale.

More on pineapple itself: the pineapple page.

The food behind this question

Pineapple, bromelain and the dose on the label — numbers, evidence and safety

The same question for other foods (pregnancy)

Sources

ev-pinpg-01 · Observational data · retrospective cohort · n = 2400
First,cervical ripening: the mean Bishop score at admission was significantly higher in the exposed group (6.2 ± 1.3) compared to the unexposed group (5.4 ± 1.5), P < .001.
Who: pregnant women aged 18 to 45 delivering 2018 to 2023 in Nigeria; 1,200 self-reported regular third-trimester pineapple eaters vs 1,200 non-eaters
Effect: Bishop score 6.2 +/- 1.3 vs 5.4 +/- 1.5 (P < .001); adjusted mean difference 0.8 (95% CI 0.5 to 1.1); labor 8.5 vs 10.2 hours
Certainty: Self-report 4-8 weeks before delivery; the participants section has contradictory numbers (2900 eligible, 'two hundred' in the analysis versus 2400); residual confounding. Not evidence that pineapple starts labor.
Medicine (Baltimore), 2026, pineapple consumption and cervical ripening, Nigeria · checked 2026-10-07 · we read the fulltext
ev-pinpg-02 · Observational data · retrospective cohort · n = 2400
Secondary outcomes showed no significant differences in neonatal birth weight, Apgar scores, or NICU admissions between the 2 groups.
Who: Nigerian retrospective cohort, pineapple eaters vs non-eaters in the third trimester
Effect: no significant differences in neonatal birth weight, Apgar scores or NICU admissions
Certainty: No difference in a weak design; data on early pregnancy and miscarriage were not collected (births only).
Medicine (Baltimore), 2026, pineapple consumption and cervical ripening, Nigeria · checked 2026-10-07 · we read the fulltext
ev-pinpg-03 · Observational data · retrospective cohort · n = 2400
Finally, as a retrospective investigation, the study is limited in establishing definitive cause-and-effect relationships.
Who: Nigerian retrospective cohort
Effect: recall bias, unmeasured confounders, imprecise exposure; no cause-and-effect inference
Certainty: Knowledge boundary: there are no randomized peer-reviewed trials of pineapple in pregnant women.
Medicine (Baltimore), 2026, pineapple consumption and cervical ripening, Nigeria · checked 2026-10-07 · we read the fulltext
ev-pinpg-04 · Laboratory or animal data · animal study · n = 4 groups of rats
Neither fetal death, nor provoked vaginal bleeding was observed in the pregnant rats.
Who: pregnant Wistar rats, unripe pineapple juice 250, 500 or 1000 mg/kg orally on days 7 to 14
Effect: no change in live fetuses, implantation sites or resorption; no fetal death or vaginal bleeding
Certainty: Animals; unripe juice (the one used as a folk abortifacient); does not transfer directly to humans.
European Journal of Contraception and Reproductive Health Care, 2011, Ananas comosus unripe fruit juice in pregnant Wistar rats · checked 2026-10-07 · we read the abstract
ev-pinpg-05 · Laboratory or animal data · in vitro organ bath study · n = tissue strips
Aqueous fraction (F4) possesses uterine stimulant property which was blocked by verapamil but unaffected by indomethacin, prazosin and atosiban.
Who: isolated uterine muscle from pregnant SD rats and pregnant human myometrium; extract fractions 0.1 to 10 mg/ml
Effect: aqueous fraction F4 stimulated contraction; blocked by verapamil; ketanserin cut the response by 74.3%
Certainty: Extract concentrates on tissue in a bath, not an eaten fruit.
Journal of Ethnopharmacology, 2016, Investigation of uterotonic properties of Ananas comosus extracts · checked 2026-10-07 · we read the abstract
ev-pinpg-06 · Laboratory or animal data · in vitro and in vivo animal study · n = rats
Contrary to the folklore use, unripe F4 did not stimulate the uterine activity during pregnancy and postpartum.
Who: pregnant rats at E18 and postpartum rats, oral pineapple fraction F4 1.5 g per 3.5 oz (100 g) body weight
Effect: no uterine stimulation in pregnant rats; increase only postpartum with ripe F4; unripe F4 inactive
Certainty: Animals; dose in grams per 3.5 oz (100 g) of weight, unattainable from food. The folk belief about unripe pineapple was not confirmed.
Phytomedicine, 2018, Role of the serotonergic pathway in uterotonic activity of Ananas comosus · checked 2026-10-07 · we read the abstract
ev-pinpg-07 · Meta-analysis or systematic review · systematic review of RCTs (PROSPERO CRD42020221395) · n = 7 RCTs
The general effect of bromelain supplementation on inflammation is inconsistent because of population heterogeneity, doses used, treatment duration, and parameters evaluated.
Who: adults in RCTs of bromelain alone or combined with other oral compounds (no pregnant women)
Effect: no pooled estimate; effects inconsistent across populations, doses and markers
Certainty: Not about pregnant women and not about the fruit: bromelain supplements.
Clin Nutr ESPEN, 2023 · checked 2026-10-07 · we read the abstract
ev-pinpg-08 · Meta-analysis or systematic review · systematic review of RCTs · n = 7 RCTs
In relation to doses supplemented, the studies with associated bromelain ranged from 99.9 to 1200 mg/day and the supplementation time ranged from 3 to 16 weeks.
Who: adults in RCTs of bromelain supplements
Effect: doses 99.9 to 1200 mg/day; 3 to 16 weeks
Certainty: Dose context: the fear that "bromelain induces labor" rests on capsule doses; the content in the fruit was not measured here.
Clin Nutr ESPEN, 2023 · checked 2026-10-07 · we read the abstract
ev-pinpg-09 · Meta-analysis or systematic review · systematic review and random-effects meta-analysis · n = 9 studies (pain outcome)
Pain reduction from oral bromelain was slightly but significantly better than controls (mean difference in pain score = -0.27; 95% CI: -0.45, -0.08; n = 9; I2 = 29%).
Who: clinical studies of oral bromelain versus controls, searched to August 2022
Effect: pain score MD -0.27 (95% CI -0.45 to -0.08), I2 = 29%
Certainty: Not about pregnant women; no full text in PMC (no_pmc).
Nutrition and Health, 2023, Efficacy and safety of bromelain: A systematic review and meta-analysis (Leelakanok et al.) · checked 2026-10-07 · we read the abstract
ev-pinpg-10 · Randomized controlled trial(s) · exclusion criteria of a randomized trial · n = 60
Patients with any disturbing factor to wound healing (i.e., uncontrolled diabetes, malnutrition, immunosuppression, corticosteroid regimens, and radiotherapy), allergy to pineapple, any other diagnosis rather than SCC or BCC, active infections, and warfarin administration (due to possible contraindication with bromelain) were excluded from the study.
Who: 60 patients after Mohs surgery, Tehran; exclusion criteria
Effect: warfarin users and people with pineapple allergy excluded; no interaction measured
Certainty: A caution from the researchers, not a measured interaction. Concerns bromelain supplements, not a serving of fruit; pregnant women on anticoagulants: a question for the doctor.
BMC Surg, 2026 · checked 2026-10-07 · we read the fulltext
ev-pinpg-11 · Position of an expert body · government health information page · n = —
Little is known about whether it’s safe to use bromelain during pregnancy or while breastfeeding.
Who: pregnant and breastfeeding women considering bromelain supplements
Effect: safety in pregnancy and lactation unknown; most common side effects stomach upset and diarrhea
Certainty: About a bromelain supplement, not the fruit as food.
NIH National Center for Complementary and Integrative Health, Bromelain · checked 2026-10-07 · we read the section

How this page was made. Evidence was extracted from primary sources into cards, every number was re-checked against the source, and the text was written from those cards. Bioma Learn has no human medical reviewer at this time, and we say so rather than invent one. Methodology. This is information, not medical advice.