Early Signs Of Pregnancy

  • Prachi Gupta Bachelor of dental surgery, Master of Public Health
  • Margaret Musanga Malenya Bachelor of Science - BS, Physical Therapy/Therapist, Universidad CEU San Pablo, Madrid, Spain


Definition of pregnancy and its significance

Pregnancy is the biological process through which a female's body transforms in order to nourish and develop a fertilized egg into a fetus, culminating in delivery. The uterus provides the required environment for the baby's development by allowing the egg to fertilize and the fetus to thrive.1,2 

Importance of recognizing early signs of pregnancy

Recognizing early pregnancy indicators is critical for a variety of reasons. For starters, early identification allows pregnant moms to begin prenatal treatment as soon as possible, which can enhance both maternal and fetal health outcomes. It aids in the early detection of possible issues and ensures that relevant medical measures are offered.1,4 

Furthermore, being aware of the pregnancy early on helps moms to make appropriate lifestyle adjustments, such as nutrition and exercise, for the development of the kid. Early discovery is also critical for emotional and psychological preparedness, allowing the family to plan for forthcoming changes and obligations.

Overview of the stages of pregnancy

Pregnancy stages are commonly separated into three trimesters. The fertilized egg implants into the uterus during the first trimester, and the main organs and body systems of the embryo begin to develop. The second trimester, which lasts from weeks 13 to 27, is distinguished by the fetus' fast development and the mother's visible bodily changes. 

At this point, the baby's motions are discernible. The third trimester, which lasts from weeks 28 to 40, is when the fetus continues to develop, acquires weight, and adopts the right head-down position for delivery.

Conception and early pregnancy

Explanation of conception and fertilization

Conception is the first stage of pregnancy, and it happens when a male sperm cell successfully fertilizes a female egg cell. This is most commonly observed during sexual intercourse when sperm is ejaculated into the woman's vagina. The sperm passes through the cervix, into the uterus, and finally into the fallopian tube, which contains the egg. 

Fertilization occurs in the fallopian tube when one sperm enters the egg, resulting in the formation of a zygote—a single-celled embryo containing all of the genetic material from both parents. The zygote begins to divide cells as it moves down the fallopian tube towards the uterus after fertilization.1,2 

Implantation process and its role in early pregnancy

The growing embryo enters the uterus around 6-7 days after fertilization, and the implantation process begins. Implantation is critical for early pregnancy since it includes the embryo's connection to the uterine lining. The embryo's outer layer, known as the trophoblast, interacts with the uterine lining during this process, and specialized cells from the trophoblast form a link that allows the embryo to get nutrients and oxygen from the mother's blood. This link eventually develops into the placenta, which is essential for nourishing and sustaining the developing fetus during the pregnancy.

The development of the embryo in the first few weeks

The embryo develops rapidly and crucially in the first several weeks following implantation. The zygote has evolved into a blastocyst by the end of the first week, which is a hollow structure composed of an inner cell mass and an outside layer of cells. The blastocyst grows and embeds itself farther into the uterine lining during the second week. 

The inner cell mass divides into two layers during the third week: the epiblast and the hypoblast. The epiblast eventually forms the embryo, whereas the hypoblast helps to produce the yolk sac. During the third week, the process of gastrulation results in the formation of three germ layers: ectoderm, mesoderm, and endoderm, from which all major organs and tissues will ultimately grow. 

The neural tube begins to form towards the end of the third week, indicating the beginning stages of central nervous system development. The embryo is about 1/25 of an inch long by the fourth week, and its essential structures, such as the brain, heart, and limb buds, have begun to develop.4

Common early signs of pregnancy

Missed period

1. Explanation of menstrual cycle and its disruption in pregnancy

The menstrual cycle is a regular process that happens in reproductive-age females. It usually lasts around 28 days, however it varies from woman to woman. During the menstrual cycle, the body undergoes hormonal changes that prepare the uterus for a possible pregnancy. 

If there is no fertilization, the thicker uterine lining is removed during menstruation, resulting in a period. In the case of pregnancy, however, the fertilized egg implants into the uterine lining, and hormonal changes suppress menstruation, resulting in a missed period.5

2. Other factors that can cause a missed period (not due to pregnancy)

These are among causes that might cause a missing period (not related to pregnancy).

  • Stress 
  • Severe weight loss or gain
  • Hormonal imbalances
  • Polycystic ovarian syndrome (PCOS)
  • Thyroid abnormalities, certain drugs
  • Extreme exercise
  • Medical illnesses affecting the reproductive system 

These conditions can disturb natural hormonal swings and influence menstrual cycle regularity, resulting in irregular or skipped periods. If a woman misses her period and believes she is pregnant, or if she develops other troubling symptoms, she should visit a healthcare practitioner to identify the underlying reason.6

Morning sickness

1. Definition and symptoms of morning sickness

Morning sickness is the nausea and vomiting that some pregnant women suffer in the early hours of the day. It can, however, occur at any time of day and is a frequent symptom of pregnancy. Symptoms include nausea, vomiting, and occasionally an aversion to specific foods or scents.2

2. Possible causes and triggers

Although the specific reasons of morning sickness are unknown, hormonal changes during pregnancy, including higher levels of human chorionic gonadotropin (hCG) and estrogen, are thought to have a role. Other possible causes include increased sensitivity to specific scents or foods, stress, exhaustion, and a woman's unique predisposition to morning sickness.2

3. Management and remedies for morning sickness

Morning sickness can be managed and treated by eating small, frequent meals, avoiding triggers like strong scents or greasy/fatty foods, staying hydrated, getting plenty of rest, and using ginger-based products or vitamin B6 supplements (under medical supervision). In more severe situations, doctors may prescribe anti-nausea medicine.2

Breast changes

1. Description of breast tenderness, swelling, and darkening of the areolas

Breast tenderness is a frequent symptom of early pregnancy, characterized by increased sensitivity and pain in the breasts. The breasts may also enlarge, making them appear bigger and heavier. Furthermore, the areolas, the black skin around the nipples, may deepen and become more visible.

2. Hormonal changes and their effects on breasts during early pregnancy

During early pregnancy, hormonal changes, notably higher levels of estrogen and progesterone, drive the formation of milk ducts and blood vessels in the breasts. These hormonal changes also cause increased blood flow and water retention in the breast tissues, resulting in breast discomfort and edema. The same hormonal changes are considered to impact the darkening of the areolas. These breast alterations, which are considered typical during early pregnancy, prepare the breasts for possible lactation.4,5


1. Explanation of extreme tiredness in early pregnancy

Extreme exhaustion, often known as fatigue, is a typical and natural response to the body's hormonal changes and higher metabolic needs during this time of pregnancy. The body is working hard to maintain the developing embryo, and hormonal changes, notably high levels of progesterone, can cause fatigue and tiredness.1

2. Factors contributing to fatigue during this stage

Several factors contribute to weariness during early pregnancy, including increased production of sedative hormones such as progesterone and human chorionic gonadotropin (hCG). The body's greater effort to provide nourishment and maintain the developing embryo, as well as potential changes in blood pressure and blood sugar levels, can all contribute to excessive weariness during this time.1

Frequent urination

1. Increased need to urinate and its link to pregnancy

Pregnancy is usually associated with an increased desire to urinate owing to hormonal changes that result in increased blood flow to the kidneys and higher urine filtration. Furthermore, as the uterus grows, it puts pressure on the bladder, diminishing its capacity and increasing the desire to pee regularly.2,3

2. Physiological changes causing frequent urination

Elevated levels of hormones such as human chorionic gonadotropin (hCG) and progesterone, which increase blood flow to the kidneys and increase urine output, are among the physiological changes that cause frequent urination during pregnancy. The uterus displaces the bladder as it grows, resulting in decreased bladder capacity and more frequent trips to the bathroom.2,3

Less common early signs of pregnancy

Spotting and Light Bleeding

1. Understanding implantation bleeding and its differentiation from menstruation

Implantation bleeding is defined as light spotting or light bleeding that occurs when the fertilized egg implants into the uterine lining, typically 6-12 days after conception, and it differs from menstruation in that it has a lighter flow, a shorter duration, and occurs at a different time in the menstrual cycle.2,4

2. When to seek medical attention for bleeding during early pregnancy

Seek medical assistance if you have excessive bleeding, significant discomfort, or have worries about your pregnancy, since this may suggest potential issues that require investigation by a healthcare expert.

Changes in taste and smell

1. Description of food aversions and cravings

Food aversions during pregnancy relate to a strong distaste or revulsion towards certain meals, whereas cravings are intense urges for specific foods, both of which are typical throughout pregnancy and are impacted by hormonal changes.1,2

2. Hormonal influences on the senses during pregnancy

Increased levels of estrogen and human chorionic gonadotropin (hCG) during pregnancy can heighten the sensations of taste and smell, leading to the development of food aversions and desires.1,2,4

Mood swings

1. Emotional changes and mood swings in early pregnancy

Early pregnancy is characterized by emotional shifts and mood swings caused by changing hormones such as estrogen and progesterone, which can cause emotions of irritation, melancholy, or exhilaration. 1,2

2. Coping strategies and emotional support during this time

Maintaining a healthy lifestyle, getting social support from loved ones, practising relaxation techniques such as meditation or deep breathing, and addressing feelings with a healthcare practitioner or counselor if necessary are all coping tactics and emotional support at this time.1,3

When to take a pregnancy test

The best time to take a pregnancy test for accurate results is after a missed period. Because most home pregnancy tests can detect the pregnancy hormone hCG in urine by then. There are several types of pregnancy tests available, including urine-based tests that are routinely used at home and blood tests that may be done at a healthcare provider's office, which give greater sensitivity and early pregnancy detection.

Follow the directions supplied with the home pregnancy test, use the first-morning pee (which includes greater amounts of hCG), and wait the specified period before interpreting the findings for reliable results.5

Seeking medical care

Prenatal care is critical for the health and well-being of both the pregnant woman and the growing baby because it allows healthcare practitioners to monitor the pregnancy, discover any issues early, and give necessary guidance and interventions.5

Expectant moms may anticipate a complete examination during their first prenatal appointment, which includes obtaining a medical history, completing physical exams, running blood and urine tests, and addressing health behaviours and lifestyle modifications to ensure a successful pregnancy.5

Severe stomach discomfort, copious vaginal bleeding, abrupt swelling, persistent headaches, reduced fetal activity, and symptoms of premature labour are all potential issues and warning signs to look out for during pregnancy that require prompt medical treatment.6


To summarize, Fertilization happens during the early stages of pregnancy when a sperm successfully enters an egg, resulting in the formation of a zygote. The zygote divides rapidly and travels to the uterus, where it implants into the uterine lining, resulting in the development of the embryo, which grows rapidly and develops organs throughout the first few weeks.


  1. Macklon NS. Conception to ongoing pregnancy: the ‘black box’ of early pregnancy loss. Human Reproduction Update. 2002 Jul 1;8(4):333–43. [accessed 2 Aug 2023] Available from: https://academic.oup.com/humupd/article-lookup/doi/10.1093/humupd/8.4.333
  2. Norwitz ER, Schust DJ, Fisher SJ. Implantation and the Survival of Early Pregnancy. N Engl J Med. 2001 Nov 8;345(19):1400–8. [accessed 2 Aug 2023] Available from: http://www.nejm.org/doi/abs/10.1056/NEJMra000763
  3. Rubertsson C, Hellström J, Cross M, Sydsjö G. Anxiety in early pregnancy: prevalence and contributing factors. Arch Womens Ment Health. 2014 Jun 1;17(3):221–8. [accessed 2 Aug 2023] Available from: https://doi.org/10.1007/s00737-013-0409-0
  4. Wallach E, Batzer FR. Hormonal Evaluation of Early Pregnancy. Fertility and Sterility. 1980 Jul 1;34(1):1–13. [accessed 2 Aug 2023] Available from: https://www.sciencedirect.com/science/article/pii/S0015028216448296
  5. Spencer TE. Early pregnancy: Concepts, challenges, and potential solutions. Animal Frontiers. 2013 Oct 1;3(4):48–55. [accessed 2 Aug 2023] Available from: https://academic.oup.com/af/article/3/4/48/4638665
  6. Wang X, Chen C, Wang L, Chen D, Guang W, French J. Conception, early pregnancy loss, and time to clinical pregnancy: a population-based prospective study. Fertility and Sterility. 2003 Mar 1;79(3):577–84. [accessed 2 Aug 2023] Available from: https://www.sciencedirect.com/science/article/pii/S0015028202046940
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Prachi Gupta

Bachelor of dental surgery, Master of Public Health

Dr. Prachi Gupta is a distinguished dentist and accomplished public health professional with extensive experience. With a successful career spanning several years, she has demonstrated exceptional disease prevention and promotion expertise. Driven by a passion for improving community well being, she combines her health and safety proficiency with public health insights to promote holistic health. A dedicated advocate for overall wellness, she continues to positively impact lives through her roles in dentistry and public health.

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