48 Fun Facts About Pregnancy

A full-term human pregnancy lasts roughly how long from the last period?

About 40 weeks from the last menstrual period, or just over nine months; counted from fertilisation it is roughly 38 weeks.

Pregnancy is divided into how many trimesters?

Pregnancy is divided into three trimesters of roughly three months each, together spanning about 40 weeks.

At what point does a developing baby stop being called an 'embryo' and start being a 'fetus'?

The embryo becomes a fetus at about ten weeks' gestational age, counted from the last period, which is roughly eight weeks after fertilisation.

Which nutrient is advised before and during early pregnancy to prevent neural tube defects?

Folic acid taken before conception and in early pregnancy lowers the risk of neural tube defects such as spina bifida; 400 micrograms a day is the usual advice.

Roughly what share of pregnant women experience morning sickness to some degree?

Morning sickness affects about 70 to 80% of pregnant women, typically between the 4th and 16th weeks; the severe form is hyperemesis gravidarum.

Which hormone do pregnancy tests detect in blood and urine?

Pregnancy tests detect hCG (human chorionic gonadotropin), a hormone the placenta makes soon after implantation; rising hCG is also thought to contribute to morning sickness.

What are the harmless 'practice' tightenings before real labour called?

Braxton Hicks contractions are irregular, usually painless tightenings of the uterus; they can begin as early as the sixth week but are mostly noticed in the second or third trimester.

In what year did an English physician first describe the 'practice' contractions that bear his name?

They were first described in 1872 by an English physician who was studying the later stages of pregnancy in London.

What is the term for the first time a mother feels her baby move?

Quickening is the first time the mother feels the baby move, typically in the second trimester; the early flutters are often mistaken for gas or hunger pangs.

What is 'sympathetic pregnancy', in which a partner shares the symptoms, formally called?

Couvade syndrome, from the French 'couver' (to brood or hatch), is the name for a partner developing pregnancy-like symptoms; whether its cause is psychosomatic or hormonal is debated.

Twins from a single fertilised egg that splits are described as what?

Identical (monozygotic) twins come from one fertilised egg that splits into two embryos, so they share virtually all their DNA.

How much genetic material do fraternal twins share, like any siblings?

Fraternal twins come from two separate eggs, so like any full siblings they share about 50% of their genes; identical twins share nearly all their DNA.

What do you call three babies born at once?

Three babies born at once are triplets; four are quadruplets and eight are octuplets.

The first surviving set of octuplets on record, born in 2009 in California, carry which surname?

Nadya Suleman gave birth to the octuplets in January 2009 at a hospital in Bellflower, California; all eight survived, a first for octuplets.

The extremely rare event of conceiving a second baby while already pregnant is called what?

Superfetation means a second egg is fertilised and implants while a pregnancy is already under way; only a handful of human cases have ever been documented.

Which animal has the longest gestation of any mammal, at about 22 months?

The African elephant carries its calf for about 22 months, the longest gestation of any mammal; a human pregnancy is about nine months by comparison.

On average, how long after fertilisation does an embryo implant in the uterus?

The blastocyst implants in the uterine wall about 8 to 9 days after fertilisation, within a range of roughly six to twelve days; light implantation bleeding can be an early sign.

At 28 weeks, roughly what share of babies can survive outside the womb with good medical care?

With good neonatal care more than 90% of babies born at 28 weeks survive, though many face complications such as breathing problems and long hospital stays.

A baby born before which point is considered 'preterm'?

Birth before 37 weeks is preterm; 39 to 40 weeks is regarded as full term.

A pregnancy that reaches or passes 42 weeks is called what?

A pregnancy that reaches 42 weeks is post-term (also post-dates); 41 weeks up to 41 weeks and 6 days is called late-term.

What is the Latin-derived medical term for a pregnant woman?

A gravida is a pregnant woman; the word comes from Latin 'gravidus', meaning heavy or laden, the same root as 'gravity'.

Which pregnancy complication combines high blood pressure with protein in the urine?

Pre-eclampsia is diagnosed when high blood pressure develops after 20 weeks together with protein in the urine or other organ signs; untreated it can progress to eclampsia, with seizures.

Which 0-to-10 score rates a newborn's condition at one and five minutes after birth?

The Apgar score, devised by anaesthetist Virginia Apgar in 1952, rates a newborn's colour, heart rate, reflexes, muscle tone and breathing from 0 to 10 at one and five minutes after birth.

The bluish discolouration of the cervix and vulva in early pregnancy is named after whom?

Chadwick's sign is the bluish-purple tint of the cervix, vagina and vulva from increased blood flow, described by the American gynaecologist James Read Chadwick in the 1880s.

Which two of the baby's tiny middle-ear bones come from the first pharyngeal arch?

The malleus and incus form from Meckel's cartilage of the first pharyngeal arch; the stapes, the body's smallest bone, comes from the second arch.

A fetal heartbeat can usually first be seen on ultrasound at about which week?

A fetal heartbeat is usually first visible on a transvaginal ultrasound at about 6 weeks of gestation, when the embryo measures only a few millimetres.

What is the first, antibody-rich 'milk' a mother produces just after birth called?

Colostrum is the thick, yellowish first milk, rich in antibodies, produced in the first days after birth; 'beestings' is an old dialect name for it.

What is the pregnancy-linked craving for non-food substances such as chalk or soil called?

Pica is the craving for non-food substances such as clay, chalk, ice or soil; it is reported in some pregnancies and can be linked to iron deficiency.

Which term describes a fetus lying bottom-first rather than head-first near the end of pregnancy?

Breech means the baby is positioned buttocks or feet first; about 3 to 4% of babies are breech at term, and many are delivered by caesarean section.

In an ectopic pregnancy, where does the embryo most often implant?

About 95% of ectopic pregnancies implant in a fallopian tube, which is why they are often called tubal pregnancies; they cannot continue and can be life-threatening if the tube ruptures.

Roughly how often does denial of pregnancy last all the way until delivery?

Denial of pregnancy persisting all the way to delivery occurs in about 1 in 2,500 cases, while denial lasting to about 20 weeks is seen in roughly 1 in 475.

Around what fraction of recognised pregnancies end in miscarriage?

About 10 to 15% of clinically recognised pregnancies end in miscarriage, most of them because of chromosomal abnormalities in the embryo.

In which trimester is the risk of miscarriage highest?

The first trimester carries by far the highest miscarriage risk; most losses happen before 12 weeks, after which the risk falls sharply.

Which of these countries had the highest fertility rate in 2024?

Niger, in West Africa, had a fertility rate of around six children per woman in 2024, among the highest in the world; Nigeria and Afghanistan were near four and a half, India about two.

Roughly how many pregnancies occurred worldwide in 2012?

About 213 million pregnancies occurred worldwide in 2012, of which roughly 190 million (89%) were in the developing world.

Cerebral palsy is far more common in which kind of birth?

Cerebral palsy is several times more common in multiple births like twins and triplets, largely because they are far more often born prematurely and at low birth weight.

What name is given to the facial pigmentation sometimes called the 'mask of pregnancy'?

Melasma, also called chloasma or the 'mask of pregnancy', is a patchy brown pigmentation of the face triggered by pregnancy hormones and sunlight; it usually fades after delivery.

What is the McCaughey family, of Des Moines, famous for in 1997?

Bobbi and Kenny McCaughey's seven babies, born in November 1997 in Des Moines, Iowa, were the first septuplets known to survive infancy.

Which hormone drives the contractions of labour and is given synthetically to induce it?

Oxytocin, released by the pituitary gland, drives the contractions of labour and the let-down of breast milk; a synthetic form, sold as Pitocin or Syntocinon, is used to induce or speed up labour.

Which vaccine-preventable infection in early pregnancy classically causes deafness and heart defects in the baby?

Rubella (German measles) caught in the first trimester can cause congenital rubella syndrome, with deafness, cataracts and heart defects; MMR vaccination before pregnancy prevents it.

Naegele's rule for a due date adds a year to the last period's date, subtracts three months, then adds how many days?

It assumes a 280-day gestation; real births scatter around the estimate with a standard deviation of about two weeks.

Because it is genetically different from the mother, the fetus is described as an unusually successful what?

The fetus is often called a successful allograft: tissue from a genetically different individual that the mother's immune system tolerates rather than rejects, a puzzle first framed by immunologist Peter Medawar in the 1950s.

How much total weight gain does the Institute of Medicine recommend for a normal-BMI singleton pregnancy?

For a normal-BMI singleton pregnancy the Institute of Medicine's 2009 guidelines advise a total gain of 25-35 pounds; underweight women are advised 28-40 lb, overweight 15-25 lb and obese 11-20 lb.

Smoking in pregnancy is associated with roughly how much higher odds of preterm birth?

Smoking in pregnancy raises the odds of preterm birth by about 30%; it also roughly doubles the risk of premature rupture of membranes, placental abruption and placenta praevia.

How many minutes of moderate exercise per week does the American College of Sports Medicine advise in pregnancy?

The American College of Sports Medicine, like ACOG, advises at least 150 minutes of moderate exercise a week in a healthy pregnancy, while avoiding heavy lifting, overheating and high-impact or contact sports.

What is the term for the cervix thinning and shortening in preparation for birth?

Effacement is the thinning and shortening of the cervix before and during labour, measured in percent; it goes along with dilation, the opening of the cervix measured in centimetres.

Which WHO and UNICEF programme, launched in 1991, certifies hospitals for supporting breastfeeding?

The Baby-Friendly Hospital Initiative, launched by WHO and UNICEF in 1991, designates hospitals that implement the 'Ten Steps to Successful Breastfeeding', such as rooming-in and early skin-to-skin contact.

Globally, roughly what share of pregnancies in 2010-14 were estimated to be unplanned?

An estimated 44% of pregnancies worldwide in 2010-14 were unintended, and about 56% of those ended in abortion; the later 2015-19 estimate rose to 48%.