At 37 weeks, your pregnancy is classified as “early term,” and most natural methods for encouraging labor have limited evidence of effectiveness at any gestational age. More importantly, major obstetric organizations strongly discourage elective delivery before 39 weeks because babies born at 37 weeks face measurably higher risks of breathing problems and hospitalization. That said, some pregnancies do have medical reasons for earlier delivery, and understanding what the evidence says about natural induction methods can help you have a more informed conversation with your provider.
Why 37 Weeks Is Earlier Than You Think
Full term starts at 39 weeks, not 37. The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine have long discouraged nonindicated delivery before 39 weeks of gestation. Those final two weeks matter more than they might seem. A retrospective study of over 4,600 infants found that babies born at 37 weeks had a hospitalization rate of 30.1%, compared to 21.4% for babies born at 39 weeks or later. The risk of transient tachypnea of the newborn, a breathing condition where fluid lingers in the lungs, was 2.3 times higher at 37 weeks than at 39 weeks.
None of this means 37-week delivery is never appropriate. If you have preeclampsia, gestational diabetes with complications, cholestasis, or another medical condition that makes continuing the pregnancy riskier than delivering, your provider may recommend delivery in the 37-week range. In those cases, ACOG’s guidance is clear: delivery should happen regardless of gestational age when there’s a genuine medical indication. The timing decision should always be individualized to the patient.
If your desire to induce stems from discomfort, anxiety, or scheduling preferences, the evidence strongly favors waiting. The methods below are worth understanding, but attempting them at 37 weeks without a medical reason introduces risk with very little proven benefit.
Nipple Stimulation
Nipple stimulation is the natural method with the most plausible biological mechanism. When the nipple is stimulated, either by hand or with a breast pump, the posterior pituitary gland releases oxytocin in pulses. This is the same hormone hospitals use (in synthetic form) to induce labor, and it’s the same hormone released when a baby breastfeeds after birth.
In clinical trials, the typical protocol involves using an electric breast pump or manual stimulation for periods of at least 30 minutes, with breaks of up to 15 minutes as needed, for a cumulative total of about two hours. This approach has been studied as an inpatient method, meaning it was done under medical supervision with fetal monitoring. That distinction matters because oxytocin can cause contractions that are too strong or too frequent, which poses risks to the baby. Doing this unsupervised at home, especially before 39 weeks, is not the same as what the studies tested.
Sexual Intercourse
The logic behind sex as a labor trigger is twofold: semen contains prostaglandins, which are the same type of compounds used in medical cervical ripening agents, and orgasm can cause uterine contractions. In theory, this combination should help soften the cervix and stimulate labor. In practice, a systematic review found no increase in the rate of spontaneous labor after intercourse. Sex in late pregnancy is generally safe if your membranes are intact and your provider hasn’t told you otherwise, but it’s unlikely to start labor.
Dates and Diet
Eating date fruit in late pregnancy has gained popularity based on a handful of studies. Research on women who consumed dates (specifically the “rutab” variety) found a significant positive effect on the duration of the first and third stages of labor. The studies suggest dates may help labor progress more efficiently once it starts, though the evidence that they trigger labor onset is less clear. Most studies tested date consumption in the final weeks before a due date, not at 37 weeks specifically.
No dietary intervention has strong evidence for reliably inducing labor. Spicy food, pineapple, and raspberry leaf tea are commonly mentioned online, but none have demonstrated a consistent effect on labor onset in clinical research.
Evening Primrose Oil
Evening primrose oil contains linoleic acid and gamma-linolenic acid, fatty acids that the body can convert into prostaglandin-like compounds. A randomized controlled trial tested a single vaginal dose of 1,000 mg in post-term women (41 weeks or later) and found it significantly improved cervical readiness scores and reduced the time to delivery. That’s a meaningful finding, but it’s specific to post-term pregnancies in first-time mothers whose cervixes were not yet favorable for labor. Applying these results to 37 weeks is a stretch, since the cervix at 37 weeks is typically far less prepared for labor than at 41 weeks.
Walking and Movement
Upright positions and walking help the baby’s head press more directly and evenly on the cervix, which can strengthen contractions in terms of number, force, and regularity. Gravity encourages the uterine fundus to fall forward, positioning the baby anteriorly into the pelvic inlet. Movement also increases pelvic outlet diameters and strengthens pelvic floor muscles, both of which support the baby’s descent.
These benefits are well-documented for women already in labor. Walking during active labor helps contractions become more effective and can shorten labor duration. As a method for starting labor from scratch, the evidence is much weaker. Staying active in late pregnancy is good for you regardless, but a long walk is unlikely to trigger labor if your body isn’t already heading in that direction.
Acupressure
Two acupressure points are commonly cited for labor encouragement. The first, known as LI4, sits in the fleshy web between your thumb and index finger. The second, SP6, is located about four finger-widths above the inner ankle bone. In studies, these points were pressed bilaterally (both sides) for 20 minutes during existing contractions, with pressure applied during each contraction and released between them. The research focused on women already in active labor, testing whether acupressure could strengthen contractions that were already happening. There’s minimal evidence it can initiate labor in someone who isn’t contracting.
Castor Oil
Castor oil works as a strong laxative that causes intestinal cramping, which can sometimes trigger uterine contractions. A retrospective study found that about 91% of women who used a castor oil cocktail delivered vaginally with few complications, and severe side effects like nausea, vomiting, and extreme diarrhea occurred in less than 7% of cases. Adverse effects of any kind were reported in under 15% of births.
Those numbers sound reassuring, but castor oil is one of the more aggressive natural methods. The gastrointestinal distress it causes, including diarrhea and cramping, can lead to dehydration during a time when your body needs to be well-hydrated for labor. Using it at 37 weeks, before the baby has had the benefit of those final developmental weeks, adds unnecessary risk.
Recognizing Real Contractions
If you do try any of these methods and start feeling contractions, knowing whether they’re real matters. True labor contractions come at regular intervals, follow a pattern, and get closer together over time. Each one lasts about 60 to 90 seconds and steadily grows stronger. They continue regardless of whether you rest, change positions, or drink water.
Braxton Hicks contractions, by contrast, are irregular, don’t follow a predictable pattern, and typically stop if you rest or hydrate. The simplest test: time your contractions and try resting with a glass of water. If they go away, they aren’t true labor. Sometimes the only definitive way to tell is a vaginal exam to check for cervical change.
The Bigger Picture at 37 Weeks
Your body has its own timeline for labor, driven by a complex hormonal conversation between you and your baby. Most natural induction methods either lack strong evidence or have only been studied in women at or past their due dates. At 37 weeks, your cervix is likely not yet favorable for labor, which makes any induction method, natural or medical, less likely to work and more likely to lead to complications.
If you have a medical reason for early delivery, your provider can discuss both natural and medical options that are appropriate for your situation. If you’re simply ready to be done with pregnancy, the evidence consistently points to the same conclusion: those last two weeks give your baby meaningful advantages in breathing, feeding, and staying out of the hospital nursery.