There’s no single hardest part of pregnancy because the answer depends on your body, your circumstances, and which trimester you’re in. But certain challenges come up overwhelmingly often: relentless nausea in the first trimester, sleep deprivation in the third, pelvic pain that limits basic movement, and the mental health toll that can run through all nine months. Each of these affects a significant percentage of pregnant women, and understanding what’s common can help you feel less alone in it.
First Trimester Nausea and Exhaustion
Up to 70% of pregnancies involve some degree of nausea and vomiting, and for many women this is the first real shock of pregnancy. It’s called “morning sickness,” but it can last all day, disrupt work, and make eating feel impossible. For most women, it peaks between weeks 8 and 12 and gradually fades by the second trimester.
For a smaller group, it doesn’t fade. Hyperemesis gravidarum, the severe form of pregnancy nausea, affects roughly 1 to 2% of pregnancies and is the leading cause of hospitalization in early pregnancy. It involves persistent vomiting, loss of more than 5% of pre-pregnancy body weight, and sometimes dangerous drops in electrolytes like potassium. The distinction between “bad morning sickness” and HG comes down to whether you’re losing weight, becoming dehydrated, or unable to keep any food or fluids down for extended periods. Women with HG often describe it as the most isolating experience of their lives, partly because others dismiss it as normal nausea.
Sleep Gets Worse as Pregnancy Progresses
Sleep trouble is one of the most underestimated parts of pregnancy. At least one-third of pregnant women experience insomnia, and it gets dramatically worse in the final months. A large meta-analysis of over 24,000 participants found the overall prevalence of third-trimester insomnia was about 42%, with individual studies reporting rates as high as 60%. The risk of insomnia in the third trimester is roughly double what it is in the first and second trimesters combined.
The causes pile on top of each other: frequent urination, hip and back pain from the extra weight, difficulty finding a comfortable position, heartburn when lying flat, and restless legs. Unlike postpartum sleep deprivation, which at least has an external cause you can point to, pregnancy insomnia feels like your own body is sabotaging you before the baby even arrives. Many women describe arriving at labor already exhausted.
Pelvic and Back Pain That Limits Daily Life
About one in four pregnant women develops pelvic girdle pain, a deep ache in the front or back of the pelvis that can make walking, climbing stairs, rolling over in bed, or standing on one leg painful. Studies from multiple countries put the prevalence between 18% and 30%. It tends to worsen as pregnancy progresses and the joints loosen further under the influence of the hormone relaxin.
What makes pelvic pain particularly difficult is how it interferes with everything. It limits your ability to exercise (which would otherwise help with sleep, mood, and energy), makes caring for older children harder, and can turn basic errands into ordeals. Women who experienced pelvic girdle pain in a previous pregnancy are more likely to have it again, and those who aren’t physically active before or during pregnancy tend to report higher rates. Physical therapy, support belts, and modifying daily movements can help, but for many women it’s simply something to endure until delivery.
The Mental Health Toll
About 10% of pregnant women worldwide experience a diagnosable mental health condition during pregnancy, primarily depression. In lower-income countries, that number rises to nearly 16%. These aren’t just mood swings or occasional tearfulness. Prenatal depression involves persistent sadness, loss of interest in things you used to enjoy, difficulty concentrating, and sometimes intrusive thoughts about the pregnancy or your ability to be a parent.
Anxiety during pregnancy is equally common and often overlooked. Worrying about the baby’s health, about labor, about finances, or about your relationship can escalate from normal concern into something that disrupts your sleep, your appetite, and your ability to function. Poverty, lack of social support, exposure to violence, and extreme stress all increase the risk, but prenatal depression and anxiety can affect anyone regardless of circumstances.
Body image adds another layer. Research shows that negative feelings about pregnancy-related body changes, including weight gain, skin changes, and shifting proportions, increase the likelihood of prenatal depression by nearly one and a half times. Women who feel strongly distressed about physical changes in their bodies consistently report higher depressive symptoms. On the other hand, having a genuinely positive attitude toward the pregnancy itself appears to act as a buffer against depression, which suggests that how you feel about what’s happening matters as much as what’s physically happening.
Working Through Pregnancy
Among women who were employed before or at conception, about 82% continue working until at least one month before delivery. That means the vast majority of pregnant women are navigating nausea, fatigue, pelvic pain, insomnia, and emotional strain while still showing up to a job. For women in physically demanding roles, standing for long shifts or lifting heavy objects becomes increasingly difficult. For those in desk jobs, sitting for hours can worsen back pain and swelling.
The social dimension is hard too. Deciding when to disclose the pregnancy, managing others’ unsolicited opinions, and handling the subtle (or not so subtle) shift in how coworkers and managers treat you all add stress. Many women describe feeling pressure to perform as though nothing has changed while their bodies are doing something enormously taxing.
The Third Trimester Wall
The final weeks of pregnancy combine nearly every difficulty into one concentrated period. Braxton Hicks contractions, the irregular tightening of the uterus that increases in frequency as the due date approaches, add a layer of physical discomfort and mental uncertainty. They feel like mild menstrual cramps or a tightening across the abdomen, and while they’re not dangerous, they can be unsettling, especially for first-time mothers who aren’t sure whether what they’re feeling is real labor.
By this point, sleep deprivation is at its worst, mobility is most limited, and the emotional weight of anticipating labor and delivery can feel overwhelming. Many women describe the final two to four weeks as a strange limbo: too uncomfortable to do much, too anxious to relax, and tired of well-meaning people asking if the baby has arrived yet. The physical burden of carrying an additional 25 to 35 pounds, much of it concentrated in the front of the body, makes even basic tasks like putting on shoes or getting out of a car feel like accomplishments.
The Hormonal Cliff After Delivery
While technically postpartum, the hormonal crash after birth is so closely tied to the pregnancy experience that most women consider it part of the same journey. Estrogen, progesterone, and cortisol, all of which built up steadily over nine months, plummet immediately after the placenta is delivered. This sudden drop triggers mood swings, anxiety, hot flashes, and heightened emotions in the first days after birth.
For most women, these “baby blues” symptoms peak in the first two weeks and gradually ease. But for others, the symptoms intensify rather than fade. Persistent sadness lasting most of the day for more than two weeks, extreme irritability, and difficulty bonding with the baby can signal postpartum depression, which requires support beyond just waiting it out. The rise in oxytocin and prolactin (the hormones involved in bonding and breastfeeding) happening simultaneously with the crash in pregnancy hormones creates a volatile hormonal environment that’s closely linked to postpartum mental health disorders.
Serious Complications Add Another Layer
Beyond the universal discomforts, 3 to 8% of pregnancies are affected by preeclampsia, a condition involving dangerously high blood pressure that can develop after 20 weeks. Symptoms include severe headaches, visual disturbances like blurred vision or seeing spots, upper abdominal pain, and sudden swelling in the hands and face. Preeclampsia can progress to seizures if untreated, making it one of the most serious pregnancy complications worldwide.
What makes complications like preeclampsia especially difficult is the fear they introduce. Once you’ve been told your blood pressure is climbing or your lab results are concerning, every headache and every swollen ankle becomes a source of anxiety. The unpredictability of pregnancy complications, combined with the knowledge that the only definitive “cure” is delivering the baby, can make the final stretch feel like a high-stakes waiting game.