There are a number of ways in which pregnancy can affect sleep, but these effects are not the same throughout the entire time that you’re pregnant. Instead, the biological changes associated with each trimester influence the sleep that you might get as an expecting mom.

First Trimester

The first trimester is made up of the first 12 weeks after conception. Very early in the first trimester, the fertilized egg becomes attached to the inner wall of the uterus, and your body starts to produce high levels of the hormone progesterone. After 3 weeks, you enter the embryonic stage in which the embryo begins to grow and its organs start to develop. After 8 weeks, the embryo has continued to grow and becomes a fetus.

These changes can impact sleep in a few ways. First, increased progesterone can alter your sleep patterns. Progesterone is generally sleep-inducing, but at these elevated levels, it can disrupt a normal sleep cycle. It may make you fatigued during the day but prone to sleep disruptions at night. Second, both progesterone and the pressure on the bladder from the growing baby can increase how frequently you have to urinate. This can obviously make it harder to sleep through the night. Third, as the baby grows, swelling of the breasts, pelvic pain, and cramps can complicate efforts to settle in for a good night’s sleep.

These tips may help with sleeping while pregnant during the first trimester:

• Exercise: it seems counter-intuitive, but exercise can combat fatigue and body aches. While you don’t want to over-exert yourself, regular exercise can contribute to your sleep hygiene.
• Take naps: short naps in the afternoon can help keep you rested and offset the fatiguing effects of progesterone.
• Watch what you drink: avoid caffeinated beverages that can make it harder to fall asleep. Drink more water during the day than at night in order to reduce the nighttime need to urinate.

Morning sickness is also an issue that often arises during the first trimester. These tips may help in countering it:

• Avoid spicy foods: as delicious as that habañero salsa looks, it’s generally best to stay away from really spicy dishes, especially for dinner.
• Choose lighter foods before bed: eating a big or heavy meal soon before going to bed can exacerbate morning sickness, so try to opt for light snacks in the evening.

Second Trimester

In the second trimester (weeks 13 through 27), motion sickness usually goes away, and your body has more time to get used to hormonal changes. You may start to feel the baby moving, and cramps may occur more frequently, especially leg cramps at night. Other biological changes can include heartburn, particularly when you lie down, and vivid dreaming, which may start in the first trimester but often intensifies in the second.

Cramping, heartburn, and intense dreaming can all disrupt sleep. Bodily discomfort or acid reflux may make it hard to fall asleep, and vivid dreaming may cause you to wake up more commonly at the night.

These tips can help you best manage pregnancy and sleep during the second trimester:

• Watch out for acidic, fried, or spicy foods: while you may no longer need to worry as much about morning sickness, it’s still important to choose foods wisely so as to reduce heartburn. All of these types of foods can make it worse, so try to avoid them, especially at night.
• Elevate your head at night: you can use pillows or an adjustable bed (if you have one) to help decrease acid reflux.
• Get relaxed: deep breathing and other relaxation techniques can reduce stress and create a sense of calm when you’re going to bed. They may also help you get back to bed when you wake up in night.

Third Trimester

The third trimester starts on the 28th week of your pregnancy and brings about big changes for both you and your baby. The growth of the fetus can put a lot of strain on your lower back, and cramping from the second trimester often intensifies. Added pressure on the bladder makes trips to the bathroom to urinate more and more frequently. All of this can add up to significant discomfort that complicates both falling asleep and staying asleep.

These tips may help with pregnant sleep during the last third of your pregnancy:

• Stretch before bed: as part of your bedtime routine, build in light stretching or yoga. This can help with cramping and may also be a useful tool for relaxation.
• Use pillows strategically: careful pillow placement can get you positioned comfortably, and pregnancy pillows, which are specially designed to relieve pressure, are another option to consider.
• Try to follow a routine: despite all the potential for sleep disturbances, it’s still helpful to try to follow a consistent timeline for getting ready for bed, getting into bed, and waking up.
• Talk to your doctor: it’s OK to raise sleep concerns with your doctor. Definitely tell your doctor if you’re noticing an itchy feeling in your legs, which can be a sign of Restless Leg Syndrome, or a dramatic increase in snoring, which is a possible sign of obstructive sleep apnea.