Every mother-to-be fears the long, sleepless nights that come with having a newborn. Unfortunately these sleepless nights can kick-in long before the baby’s arrival.

Sleep patterns are largely influenced by the pregnancy trimester, according to Sydney Sleep Psychologist, Liora Kempler.

“The trajectory for most people in terms of sleep is that it’s not great in the first trimester, improves a little bit in the second trimester, and then gets worse again in the third trimester,” Dr Kempler told Huffington Post Australia.

“It’s interesting, because the same symptoms don’t tend to affect women all the way through, but at different times during their pregnancy.”

The first trimester

Common disruptions to sleep throughout the first trimester include vivid dreams, nausea, anxiety or apprehension and fatigue.

“Nausea is a big cause of poor sleep, and a lot of women find that feelings of apprehension, excitement or anxiety could be keeping them up as well,” said Dr Kempler.

Dr Kempler recommends sleeping with a full stomach to ease nausea from “morning” sickness, citing “Try having a snack before bed, or putting a snack by the bed, so you have it on hand when you wake up.”

While some women may experience restless evenings in the early stages of pregnancy, others may battle to stay awake at all.

“People might find they are extremely tired in the first trimester… they may find they are going to bed a lot earlier than they usually would, or are finding it difficult to get out of bed in the morning,” Dr Kempler said.

The second trimester

Common disruptions to sleep during the second trimester include a growing belly and foetal movement, although most women find they are able to return to normal sleeping patterns during this stage of pregnancy.

“For most people, things ease up a little bit and return to normal during the second trimester,” said Dr Kempler.

While some women may experience heightened physical discomfort due to an increase in urination frequency, this does not tend to affect the majority of women until the final trimester of pregnancy.

The third trimester

With a looming due date, non-interrupted sleep becomes a thing of the past for many pregnant women. Common causes of sleep disturbance during this trimester include foetal movement, frequent urination, cramps, restless leg syndrome and difficulty breathing.

Restless leg syndrome involves a tingly sensation in the legs and is often caused by an iron deficiency, which is best managed through supplements.

Cramping can be equally detrimental to sleeping patterns, with the incidence of leg cramps increasing during the latter stages of pregnancy. A warm shower and massage before bed may help women to better manage their cramps throughout the night.

Another major cause of disrupted sleep in the third trimester is frequent urination, with many women struggling to nurse themselves back to sleep after having visiting the bathroom on multiple occasions.

“As much as possible, try to get up, go to the bathroom and return to bed as quickly as you can so you don’t wake up fully,” Dr Kempler said.