Skip to main content

What it means if you lose weight during pregnancy, and when to worry?

Weight gain is a very real and very normal part of pregnancy, yet some women experience the exact opposite and actually lose weight during pregnancy. Pregnancy requires extra calories and extra nutrition to feed a growing baby which is why it can be very concerning if a pregnant woman begins to lose weight while pregnant.

Weight loss during pregnancy may be more common than you think and isn’t necessarily cause for alarm unless it’s a consistent pattern throughout the pregnancy and not just a short-lived dip on the scale. There are many factors that can cause a pregnant woman to lose weight, but that doesn’t mean it can’t be concerning when it happens. You should always consult your doctor if you’re concerned about your weight gain or loss during pregnancy, but here’s what it may mean if you are losing weight during pregnancy.


It’s not uncommon

Believe it or not, losing weight during pregnancy isn’t an uncommon occurrence, especially during the first trimester. Morning sickness can be one of the biggest causes of weight loss during the first trimester when some women are simply too nauseous to eat or are vomiting frequently. Pregnancy can also inspire a healthier lifestyle which can also result in some early-stage weight loss, especially if a woman begins a moderate exercise program and really focuses on their nutrition compared to their pre-pregnancy lifestyle. Typically, as Very Well Family notes, losing weight during the first trimester usually isn’t anything to worry about, especially if it’s followed by the recommended weight gain.

When should I worry about weight loss during pregnancy?

Although losing a bit of weight early in your pregnancy may not be something to worry about, there are times when it can be cause for alarm.  Severe morning sickness, clinically known as hyperemesis gravidarum, can cause harm to both the mother and the baby if not treated. According to BabyCenter, hyperemesis gravidarum is characterized by “persistent nausea, vomiting several times a day, weight loss, dehydration, reduced appetite, and fainting.” This can cause not only weight loss in the expectant mother but also harm to the baby. If you feel you’re losing weight because of severe morning sickness you should speak to your doctor immediately because you may require medical intervention.

Kimberly Henderson, DO, an ob-gyn at Health Quest Medical Practice told The Bump that pregnancy weight loss is “only a cause for concern if pregnancy weight loss hits 5 and 10 percent of a woman’s total body weight.” Pooja Shah, MD, an ob-gyn and regional medical director for Banner Medical Group AZ East explained to the website that weight loss during the third trimester could be a problem and should be brought to the attention of your doctor. Although it may be due to simple fluctuations it could also be related to low amniotic fluid or pregnancy-induced hypertension or preeclampsia. Since babies see their most growth during the third trimester most women also see an increase in their weight gain during that time. If you’re losing weight in your third trimester don’t ignore it and speak to your medical provider. You should also contact your doctor if you are experiencing any sudden, dramatic weight loss at any time.


Why did I get skinny while pregnant?

Weight gain is a part of pregnancy, so while some weight loss may be normal and no cause for concern, it shouldn’t be the goal either. That being said, some women do find a renewed commitment to their health once they find out they are pregnant and this healthier lifestyle can definitely lead to some initial weight loss. Women who are heavier before getting pregnant or have a BMI over 30 may also tend to lose a bit of weight at the beginning of their pregnancy, which may even be beneficial.

Causes of weight loss during pregnancy

As we mentioned above, morning sickness, a healthier lifestyle, and typical weight fluctuations can cause first-trimester weight loss, but any sudden weight loss should be brought to the attention of your doctor. Very Well Family notes some other potential causes for weight loss during pregnancy including;

  • Autoimmune disorders
  • Cancers
  • Eating disorders
  • Endocrine imbalance
  • Gastrointestinal diseases
  • Infections
  • Neurologic abnormalities
  • Psychiatric disorders
  • Substance use
  • Uncontrolled overactive thyroid
  • Undiagnosed diabetes
  • Other chronic diseases

“The most important intervention for a woman who is losing weight in pregnancy is to identify and treat the underlying reason for the inadequate weight gain,” explained Dr. Chris Han, a physician at the Center for Fetal Medicine and Women’s Ultrasound. While some weight loss early in the pregnancy is normal, Dr. Han also noted that “losing weight during pregnancy has been associated with increased risk of decreased birth weight and preterm delivery.”

What to do if you’re losing weight

If you find yourself struggling to gain the recommended weight during pregnancy Peanut suggests ensuring you’re eating a balanced diet full of nutrient-rich foods while limiting sugary snacks. Make sure you’re staying hydrated by drinking enough water and reducing caffeinated beverages and keeping active with light exercise.

Every woman’s pregnancy is different but if you’ve noticed a drastic weight loss or you’re struggling to gain the recommended weight reach out to your doctor for professional advice.

Editors' Recommendations

Kelli Catana
Kelli is a freelance writer who has covered the world of entertainment, pop culture, parenting, and lifestyle for various…
What is implantation bleeding like? Facts you should know about when and why this happens
Implantation bleeding vs. period bleeding: Find out the difference
A menstrual pad being held on a pink background

Heavy implantation bleeding isn't typical, but we have the answers on what is normal for implantation bleeding. What is the difference between implantation bleeding vs. period bleeding and other questions you have about implantation will all be addressed, so that you can understand what this relatively uncommon phenomenon is like.

What is implantation bleeding like?
Implantation bleeding is very light bleeding, similar to a period (in the sense that it comes out of the vaginal canal from the uterus) that happens earlier than a period would come and lasts less than two days. It can be light pink or rust brown, but it's not usually the bright or dark red that period blood can be. Implantation doesn't have any clots and can be like spotting, a light flow, or just one or two smears of blood.
Implantation bleeding is just one possible symptom of implantation, so cramping, backaches, nausea, mood swings, sore breasts, bloating, fatigue, or headaches can accompany it.

Read more
3D ultrasounds are trending: Should you get one?
3D sonograms look cool, but you want to weigh the risks and benefits
Woman in yellow dress holding 3D sonogram pregnancy announcement

Sonograms can be a highlight of pregnancy. It’s a chance for an expecting parent or parents — and perhaps even other support people like grandparents — to catch a glimpse of the developing baby on the inside. It’s a reminder of why you're enduring all those pregnancy symptoms.

During scans, you may note how incredible it is to see how fast the future baby is growing from a tiny little spec on a screen into a little one-to-be with a head, shoulders, knees, and toes.

Read more
What is implantation cramping like? Find out if what you’re feeling is early pregnancy symptoms
What to expect if you're experiencing implantation cramps
A woman having cramps

In very early pregnancy — the first moment, in fact — the new embryo implants itself into the uterine lining. This can cause what is called implantation cramping — cramps caused by the implantation of the embryo into the uterus. Learn more about what implantation cramps feel like, how long they last, and how to tell them apart from period cramps.

What does implantation cramping feel like?
Implantation cramps are milder than period cramps but the sensation can be similar to period cramps. They could be a dull ache or small twinges. Often they can feel more like prickling, pulling, discomfort, or twinges; more than full-on mild period cramping. You may feel them in the abdominal area, pelvic area, or lower back. And the feeling could be in the middle of the body or just on one side of the body.
Any cramping can be painful, including implantation cramping, though implantation cramps are rarely painful. If you do experience pain, you can use a heating pad or acetaminophen. Implantation cramps should not be extremely painful, and if you are experiencing a great deal of pain, you should seek medical attention. It could be a sign of an ectopic pregnancy or another medical emergency.

Read more