When it comes to reproductive health, there are plenty of matters you can take into your own hands. You can play it safe during sex by using a condom and eat plenty of probiotics to replenish the healthy bacteria in your vagina. However, there are some things that are better left to trained experts, like pap smears and delivering babies.

But considering there are dozens of women’s healthcare practitioners — all with various degrees, specialities, and acronyms after their last names — it can be hard to figure out who to see and when. What’s the difference between a gynecologist and a women’s health nurse practitioner (WHNP)? A doula and a midwife? Who can insert an intrauterine device (IUD) or write you a prescription for a urinary tract infection (UTI)?

To answer these questions and more, here’s the 101 on seven common medical professionals you (and your vagina) may encounter in the world of reproductive medicine.

Gynecologist
Let’s start with the one you hear all the time: the gynecologist. Gynecologists are doctors who attend medical school and residency to specialize in the female reproductive system. They perform preventative pap smears, breast exams, and pelvic exams, and can chat all things birth control, menstruation, sex, fertility, pregnancy, and menopause with you.

Speaking of contraception, your gyno can write you a prescription for birth control pills, insert and remove an IUD, administer birth control shots, and more. These doctors also diagnose and treat reproductive conditions that can impact the uterus, vagina, ovaries and cervix, like endometriosis, infertility, cancer of the reproductive organs, ovarian cysts, and breast fibroids. Gynecologists can perform surgery to treat these issues.

Obstetrician
You’ve likely heard the term “OBGYN” before, which stands for obstetrician/gynecologist. It’s common for doctors who work in women’s health to work both in gynecology and a second medical field known as obstetrics.

Obstetricians focus on the care of pregnant women and unborn babies before, during, and in the weeks following birth. If you’re expecting a little one and like your gynecologist, you can ask them if they’re also an obstetrician — there’s a good chance they are. They attend medical school and residency where they are trained to handle complex situations and surgical procedures that may arise during pregnancy and birth, like preeclampsia or cesarean sections (C-sections).

Women’s Health Nurse Practitioner (WHNP)
In order to become a WHNP, a student must first receive a bachelor’s in nursing degree and become a registered nurse (RN). From there, they can receive advanced education to become a nurse practitioner (NP) who specializes in women’s health. Nurse practitioners have more education than RNs, but less than doctors like gynecologists.

NPs and WHNPs can diagnose conditions, provide treatment, and write prescriptions, often under the supervision of a doctor. WHNPs can also perform many of the same tasks as a gynecologist, like administer pap smears, insert IUDs, write birth control prescriptions, and provide prenatal and postpartum care. This is why many women see a WHNP for most of their reproductive care needs and not a gynecologist. But unlike gynecologists and obstetricians who are doctors, WHNPs don’t deliver babies or perform surgical procedures (like a laparoscopy to diagnose endometriosis).

Reproductive Endocrinologist (REI)
REIs are gynecologists who work specifically on issues relate to human fertility (AKA baby-making). These doctors are conception experts who understand the ins and outs of fertility hormones, sperm, eggs, and reproductive anatomy like the ovaries, uterus, and fallopian tubes. REIs can diagnose and treat reproductive conditions — like polycystic ovarian syndrome (PCOS), thyroid issues, and endometriosis — that occur due to hormone imbalance and can impact a patient’s ability to get pregnant,.

Midwife
A midwife is a professional who can provide gynecological examinations, counseling, prescriptions, labor and delivery care. That’s right: Midwives can deliver babies like obstetricians and OBGYNs. There are different types of midwives with various degrees (and a variety of acronyms), however, all midwives must receive advanced training and pass an examination to practice. For example, many receive a nursing degree and then pursue advanced education, usually a masters or doctoral degree, to become a midwife. You can find these clinicians in home, hospital, and birth center settings.

One reason a patient may decide to use a midwife instead of doctor is to experience childbirth with as few medical interventions as possible, which is one aspect and goal of the midwifery care model. However, if a woman has a high-risk pregnancy (for example, if she has preeclampsia) or if complications occur during pregnancy or birth, it’s advised to seek care from an obstetrician who is trained to handle complicated issues and perform more advanced procedures.

Doula
Doulas are birth professionals who support pregnant women and their families before, during, and after delivery in hospital, birth center, and home environments. Typically, doulas receive some training. However, doulas are not licensed and do not need to earn a specific degree or certification to practice. Doulas are not clinicians and do not offer medical advice, unlike all of the previously discussed professionals.

Rather, doulas provide informational, emotional, and physical support to their clients through birth preparation, massage, labor positions, breathing and visualization techniques, breastfeeding support, basic newborn care, and more. Often times, busy doctors and nurses do not have the time to offer this level of care. Most doulas have their own private practice, though some hospitals and organizations have volunteer doula programs.

Pelvic physical therapists
Pelvic physical therapists evaluate and treat issues related to the pelvic floor, which impacts sexual, bowel, and bladder function. These professionals have the same education and training as regular physical therapists who treat muscles like the shoulder, back, or knee, but they specialize in areas like the vagina and rectum (after all, they’re muscles, too).

If you’re struggling with painful sex or vaginal exams, constipation, or endometriosis, a pelvic PT may be able to help. Pelvic physical therapy can also address changes caused by pregnancy and birth, like urinary incontinence and diastasis recti. While urinary incontinence is caused by the loss of bladder control, diastasis recti occurs due to the growing uterus stretching and separating the abdominal muscles during pregnancy. In a pelvic physical therapy session, it’s common to get a pelvic exam and perform targeted exercises (like contracting and relaxing certain muscles, such as the bladder or vagina).

Now that you better understand the spectrum of women’s health professionals (including the difference between a gynecologist and an obstetrician, and that a doctor can actually be both), you can feel confident when navigating the world of reproductive medicine — online appointment portals, stirrups, birth control, babies, and all.

English Taylor is a San Francisco-based women’s health and wellness writer and birth doula. Her work has been featured in The Atlantic, Healthline, Refinery29, NYLON, and Modern Fertility. Follow English and her work at https://medium.com/@englishtaylor or on Instagram at @englishtaylor.