Morning Sickness (Nausea in Pregnancy)

What Morning Sickness Is

Morning sickness is the everyday name for nausea and vomiting of pregnancy, sometimes shortened to NVP in the research literature. It's one of the most common early-pregnancy symptoms, with nausea reported in roughly 50% to 80% of pregnancies and vomiting in around 50%.^[4] Onset is usually within a few weeks of a missed period, symptoms peak between weeks 10 and 16, and for most people they ease after week 20, though some continue to experience symptoms later.^[3]

The most current research centers on GDF15, a hormone the body produces in response to cellular stress even outside of pregnancy. Its receptor sits in the hindbrain, in the same circuitry that governs nausea, vomiting, and appetite.^[1] During pregnancy, the feto-placental unit becomes the dominant source of GDF15 in the bloodstream, and levels rise sharply from their prepregnancy baseline. A 2023 genetic study found that people with naturally lower GDF15 levels before pregnancy tend to have a stronger reaction once that hormone spikes, a kind of sensitization that helps explain why nausea severity varies so much from person to person.^[1] That finding built on earlier genetic work linking GDF15 to hyperemesis gravidarum risk.^[2]

hCG, the hormone detected by pregnancy tests, was long proposed as a driver too, since its rise loosely tracks the same early weeks as nausea. But the evidence for a direct hCG-symptom link is inconsistent. Some studies, including cases of molar pregnancy where hCG runs five to ten times higher than typical, found no clear relationship between hCG level and how severe symptoms were.^[3]

How It's Logged

There's no blood test or scan for morning sickness itself, so it's logged as a self-reported symptom, on the days it happens and how it felt. A dated log turns scattered bad days into a pattern: whether nausea clusters in a certain window of the day, whether it's easing week over week, or whether it overlaps with other early-pregnancy symptoms like food aversions.

Why People Track Morning Sickness

Morning sickness overlaps with the broader symptom of nausea, which also shows up around ovulation, before a period, or from causes unrelated to the cycle at all. A dated pregnancy-specific log separates that context from everyday nausea, so a pattern that starts around a missed period and builds through the first trimester reads differently than nausea that shows up once and passes.

Research also finds that food aversions tend to start in close step with nausea. In one study, 60% of women who reported both symptoms had their first occurrence of each in the same week of pregnancy.^[5] Logging both side by side shows whether that overlap holds true for your own pregnancy.

How Go Go Gaia Tracks Morning Sickness

Go Go Gaia logs morning sickness with a 1-click entry in pregnancy mode, rated by severity, so it's fast enough to record however many times it happens in a day. Each entry sits on the same timeline as your other pregnancy symptoms, so you can see how nausea is trending week to week instead of relying on memory.

What the Research Shows

A 2023 study analyzing genetic and blood-hormone data found that higher maternal GDF15 during pregnancy is associated with greater risk and severity of nausea and vomiting, and that the feto-placental unit is the main source of that pregnancy-associated rise.^[1] An earlier genome-wide study had already linked variants near the GDF15 and IGFBP7 genes, both tied to placentation and appetite regulation, to hyperemesis gravidarum risk specifically.^[2]

Hyperemesis gravidarum is the clinical name for a more severe presentation of nausea and vomiting of pregnancy. Descriptions in the literature associate it with weight loss greater than 5% of prepregnancy body weight, dehydration, electrolyte imbalance, ketonuria, and orthostatic hypotension, distinguishing it from the milder, far more common pattern of morning sickness.^[4] It's estimated to affect roughly 0.3% to 3% of pregnancies globally, with rates varying by population and how it's defined.^[4]

Related Terms

Frequently Asked Questions

Educational information based on published sources. Not medical advice. For personal concerns, please consult your doctor.

What causes morning sickness?

Recent research points to GDF15, a hormone the feto-placental unit produces in sharply rising amounts during pregnancy. GDF15 acts on receptors in the brainstem that trigger nausea and vomiting, and people with naturally low GDF15 levels before pregnancy appear more sensitive to that rise once it happens.^[1] Earlier research also examined hCG, the pregnancy hormone, but its correlation with nausea severity has been inconsistent across studies.^[3]

Does morning sickness only happen in the morning?

No. Despite the name, nausea and vomiting of pregnancy can occur at any time of day, and for many people it isn't limited to mornings at all.^[3]

What is hyperemesis gravidarum?

Hyperemesis gravidarum is the clinical name for a more severe form of nausea and vomiting of pregnancy. Descriptions in the literature associate it with weight loss greater than 5% of prepregnancy body weight, dehydration, electrolyte imbalance, and ketonuria, distinguishing it from the more common, milder pattern of morning sickness.^[4] It's estimated to affect a small share of pregnancies, roughly 0.3% to 3% depending on the population studied.^[4]