2.2 From Zygote to Newborn

The most dramatic and extensive transformation of the entire life span occurs before birth. To make it easier to study, prenatal development is often divided into three main periods. The first two weeks are called the germinal period; the third through the eighth week is the embryonic period; the ninth week until birth is the fetal period (see TABLE 2.2 for alternative terms).

Germinal: The First 14 Days

Within hours after conception, the zygote begins duplication and division. First, the 23 pairs of chromosomes carrying all the genes duplicate, forming two complete sets of the genome. These two sets move toward opposite sides of the zygote, and the single cell splits neatly down the middle into two cells, each containing the original genetic code. These two cells duplicate and divide, becoming four, which themselves duplicate and divide, becoming eight, and so on. If the two-celled organism is artificially split apart and each of those two separated cells is allowed to develop (illegal for humans, successful with mice), that creates monozygotic twins. Every cell of both would have the same DNA.

First Stages of the Germinal Period The original zygote divides into (a) two cells, (b) four cells, and then (c) eight cells. Occasionally at this early stage, the cells separate completely, forming the beginning of monozygotic twins, quadruplets, or octuplets.

ALL: ANATOMICAL TRAVELOGUE/SCIENCE SOURCE

Those first cells are stem cells, able to direct production of any other cell and thus to become a complete person. After about the eight-cell stage, duplication and division continue but a third process, differentiation, begins. Soon cells specialize, taking different forms and reproducing at various rates, depending on where they are located. They are no longer omnipotent stem cells (some cells in adults can also take on other functions, but they are not nearly as adaptable as early stem cells) (Slack, 2012). For instance, even though every cell carries the complete code, differentiation means that some cells become part of an eye, others part of a finger, still others part of the brain. As one expert explains, “We are sitting with parts of our body that could have been used for thinking” (Gottlieb, 1992/2002).

About a week after conception, the multiplying cells (now numbering more than 100) separate into two distinct masses. The outer cells form a shell that will become the placenta (the organ that surrounds and protects the developing creature), and the inner cells form a nucleus that will become the embryo.

The first task of the outer cells is implantation—that is, to embed themselves in the nurturing lining of the uterus. This is far from automatic; about 50 percent of natural conceptions and an even larger percentage of in vitro conceptions never implant (see TABLE 2.3). Most new life ends before an embryo begins (Sadler, 2012).

Embryo: From the Third Through the Eighth Week

The Embryonic Period (a) At 4 weeks past conception, the embryo is only about 3 millimetres long, but already the head has taken shape. (b) By 7 weeks, the organism is about 2% centimetres long. Eyes, nose, the digestive system, and even the first stage of finger and toe formation can be seen.

OMIKRON/SCIENCE SOURCE
PETIT FORMAT/SCIENCE SOURCE

The start of the third week after conception initiates the embryonic period, during which the formless mass of cells becomes a distinct being—not yet recognizably human but worthy of a new name, embryo. (The word embryo is often used loosely, but each stage of development has a particular name; here, embryo refers to the developing human from day 14 to day 56.)

At about day 14, a thin line (called the primitive streak) appears down the middle of the embryo, becoming the neural tube 22 days after conception and eventually developing into the central nervous system, brain, and spinal column (Sadler, 2012). The head appears in the fourth week, as eyes, ears, nose, and mouth start to form. Also in the fourth week, a minuscule blood vessel that will become the heart begins to pulsate.

By the fifth week, buds that will become arms and legs emerge. The upper arms and then forearms, palms, and webbed fingers grow. Legs, knees, feet, and webbed toes, in that order, are apparent a few days later, each having the beginning of a skeletal structure. Then, 52 and 54 days after conception, respectively, the fingers and toes separate (Sadler, 2012).

As you can see, prenatally, the head develops first, in a cephalocaudal (literally, “head-to-tail”) pattern, and the extremities form last, in a proximodistal (literally, “near-to-far”) pattern. This is true for all living creatures, part of universal genetic instructions.

There’s Your Baby For many parents, their first glimpse of their future child is an ultrasound image. This is Alice Morgan, 63 days before birth.

ROBIN MORGAN

At the end of the eighth week after conception (56 days), the embryo weighs just 1 gram and is about 2½ centimetres long. It has all the organs and body parts (except sex organs) of a human being, including elbows and knees. It moves frequently, about 150 times per hour, but such movement is random and imperceptible to the mother, who may not even realize that she is pregnant.

Fetus: From the Ninth Week Until Birth

Viability This fetus is in mid-pregnancy, a few weeks shy of viability. As you can see, the body is completely formed. Unseen is the extent of brain and lung development, which will take at least another month to become sufficiently mature to allow for survival.

LENNART NILSSON SCANPIX

The organism is called a fetus from the ninth week after conception until birth. The fetal period encompasses dramatic change, from a tiny, sexless creature smaller than the final joint of your thumb to a boy or girl about 51 centimetres long.

In the ninth week, sex organs develop, soon visible via ultrasound (also called sonogram). The male fetus experiences a rush of the hormone testosterone, affecting the brain (Morris et al., 2004; Neave, 2008).

By 3 months, the fetus weighs about 87 grams and is about 7.5 centimetres long. Of course, fetal growth rates do vary—some 3-month-old fetuses do not quite weigh 80 grams and others already weigh 100.

As prenatal growth continues, the cardiovascular, digestive, and excretory systems develop. The brain increases about six times in size from the fourth to the sixth month, developing many new neurons (neurogenesis) and synapses (synaptogenesis). Indeed, up to half a million brain cells per minute are created at peak growth during mid-pregnancy (Dowling, 2004).

This brain growth is critical because it enables regulation of all the body functions, including breathing (Johnson, 2010). That allows the fetus to reach the age of viability, when a preterm newborn might survive. Thanks to intensive medical care, the age of viability decreased dramatically in the twentieth century, but it now seems stuck at about 22 weeks (Pignotti, 2010) because even the most advanced technology cannot maintain life without some brain response.

FIGURE 2.5 Each Critical Day Even with advanced medical care, survival of extremely preterm newborns is in doubt. These data come from a thousand births in Sweden, where prenatal care is free and easily obtained. As you can see, the age of viability (22 weeks) means only that an infant might survive, not that it will. By full term (not shown), the survival rate is almost 100 percent.

According to an international report published in 2012, Canada has a preterm birth rate of almost 8 percent, while the U.S. rate is 12 percent, the worst among G8 countries (Howson et al., 2012). Canada’s preterm birth rate has increased almost 25 percent from the early 1990s, when it stood at 6.5 percent (Canadian Institute for Health Information, 2009). Reasons for the increase include the greater number of older women who are having babies and the rise in rates of multiple pregnancies, often the result of taking fertility drugs. Other factors include increased rates of obesity, which can lead to high blood pressure and diabetes, and more cases of medically induced labour and Caesarean sections before pregnancies reach full term (Howson et al., 2012).

As the brain matures and the axons, or nerve fibres, connect, the organs of the body begin to work in harmony, fetal movement as well as heart rate quiet down during rest, and the heart beats faster during activity (which may be when the mother is trying to sleep).

Attaining the age of viability simply means that life outside the womb is possible (see Figure 2.5). Each day of the final three months improves the odds, not only of survival but also of life without disability (Iacovidou et al., 2010). A preterm infant born in the seventh month is a tiny creature requiring intensive care for each gram of nourishment and every shallow breath. The care and complications of preterm infants (especially conditions associated with low birth weight) are discussed at the end of this chapter. Usually, however, full-term infants are ready to thrive at home on the mother’s milk—no expert help, oxygenated air, or special feeding required. The fetus typically gains at least 2.1 kilograms in the third trimester, increasing to about 3.4 kilograms at birth (see At About This Time).

One of the Tiniest Rumaisa Rahman was born after 26 weeks and 6 days, weighing only 244 grams. Nevertheless, she has a good chance of living a full, normal life. Rumaisa gained 2270 grams in the hospital and then, six months after her birth, went home. Her twin sister, Hiba, who weighed 590 grams at birth, had gone home two months earlier. At their one-year birthday, the twins seemed normal, with Rumaisa weighing 6800 grams and Hiba 7711 grams (CBS News, 2005).

LOYOLA UNIVERSITY HEALTH SYSTEM HO/AP PHOTO

By full term, human brain growth is so extensive that the cortex (the brain’s advanced outer layers) forms several folds in order to fit into the skull (see Figure 2.6). Although some large mammals (whales, for instance) have bigger brains than humans (although not bigger in relation to one’s size), no other creature needs as many folds as humans do, because the human cortex contains much more material than the brains of non-humans. Those mammals that have bigger brains than humans also have far bigger bodies: Proportionally, human brains are largest.

FIGURE 2.6 Prenatal Growth of the Brain Just 25 days after conception (a), the central nervous system is already evident. The brain looks distinctly human by day 100 (c). By the 28th week of gestation (e), at the very time brain activity begins, the various sections of the brain are recognizable. When the fetus is full term (f), all the parts of the brain, including the cortex (the outer layers), are formed, folding over one another and becoming more convoluted, or wrinkled, as the number of brain cells increases.

Finally, a Baby

About 38 weeks (266 days) after conception, the fetal brain signals the release of hormones, specifically oxytocin, which prepares the fetus for delivery and starts labour. The average baby is born after 12 hours of active labour for first births and 7 hours for subsequent births (Moore & Persaud, 2003), although labour may take twice or half as long. The definition of “active” labour varies, which is one reason some women believe they are in active labour for days and others say 10 minutes. (Figure 2.7 shows the stages of birth.)

FIGURE 2.7 A Normal, Uncomplicated Birth (a) The baby’s position as the birth process begins. (b) The first stage of labour: The cervix dilates to allow passage of the baby’s head. (c) Transition: The baby’s head moves into the “birth canal,” the vagina. (d) The second stage of labour: The baby’s head moves through the opening of the vagina (“crowns”) and (e) emerges completely, followed by the rest of the body about a minute later. (f) The third stage of labour is the expulsion of the placenta. This usually occurs naturally, but it is crucial that the whole placenta be expelled, so birth attendants check carefully. In some cultures, the placenta is ceremonially buried, to commemorate the life-giving role it plays.

Women’s birthing positions also vary—sitting, squatting, lying down. Some women give birth while immersed in warm water, which helps the woman relax (the fetus continues to get oxygen via the umbilical cord). However, some physicians believe water births increase the rate of infection, and the underwater emergence of the head is difficult for the medical team to monitor (Tracy, 2009).

Choice, Culture, or Cohort? Both these women (in Peru on the left, in England on the right) chose methods of labour that are not typical in Canada, where birthing stools and birthing pools are uncommon. In both nations, most births occur in hospitals—a rare choice a century ago.

REUTERS/ENRIQUE CASTRO-MENDVIL

Preferences and opinions on birthing positions (as on almost every other aspect of prenatal development and birth) are partly cultural and partly personal. In general, physicians find it easier to see the head emerge if the woman lies on her back. However, many women find it easier to push the fetus out if they sit up. Neither of these generalities is true for every individual.

The Newborn’s First MinutesNewborns usually breathe and cry on their own. Between spontaneous cries, the first breaths of air bring oxygen to the lungs and blood, and the infant’s colour changes from bluish to pinkish. (Pinkish refers to blood colour, visible beneath the skin, and applies to newborns of all hues.) Eyes open wide; tiny fingers grab; even tinier toes stretch and retract. The full-term baby is instantly, zestfully, ready for life.

One assessment of newborn health is the Apgar scale (see TABLE 2.4), first developed by Dr. Virginia Apgar. When she earned her MD in 1933, Apgar wanted to work in a hospital but was told that only men did surgery. Consequently, she became an anesthesiologist. Apgar saw that “delivery room doctors focused on mothers and paid little attention to babies. Those who were small and struggling were often left to die” (Beck, 2009, p. D-1). To save those young lives, Apgar developed a simple rating scale of five vital signs—colour, heart rate, cry, muscle tone, and breathing—to alert doctors when a newborn was in crisis.

Since 1950, birth attendants worldwide have used the Apgar (often using the name as an acronym: Appearance, Pulse, Grimace, Activity, and Respiration) at one minute and again at five minutes after birth, assigning each vital sign a score of 0, 1, or 2. If the five-minute Apgar is 7 or higher, all is well.

Medical Assistance at BirthThe specifics of birth depend on the parents’ preparation, the position and size of the fetus, and the customs of the culture. In developed nations, births almost always include sterile procedures, electronic monitoring, and drugs to dull pain or speed contractions. In addition, many aspects of birth depend on who delivers the baby—doctor, midwife, or the parents themselves.

Midwives are as skilled at delivering babies as physicians, but in most nations only medical doctors perform surgery, such as Caesarean sections (C-sections), whereby the fetus is removed through incisions in the mother’s abdomen. A new endeavour in Africa to teach midwives to perform Caesareans is projected to save a million lives per year.

Caesareans are usually safe for mother and baby and have many advantages for hospitals (easier to schedule, quicker, and more expensive than vaginal deliveries, which means that hospitals make more money on C-sections), but they also bring more complications after birth and reduce breastfeeding (Malloy, 2009). Given that, it is not surprising that Caesareans are controversial. The World Health Organization (WHO) suggests that they are medically indicated in 15 percent of births. In some nations there are far fewer than that; in others, many more (see Figure 2.8).

FIGURE 2.8 Too Many Caesareans or Too Few? Rates of Caesarean deliveries vary widely from nation to nation. Aside from China, Latin America has the highest rates in the world (note that 40 percent of all births in Chile are by Caesarean), and sub-Saharan Africa has the lowest rates (the rate in Chad is less than half of 1 percent). The underlying issue is whether some women who should have Caesareans do not get them, while other women have unnecessary Caesareans.

According to the Canadian Institute for Health Information (CIHI), there are no agreed-upon benchmarks for conducting C-sections on mothers in Canada (CIHI, 2010). From 2008 to 2009, the national rate of C-sections stood at 26 percent, well above the WHO-recommended rate of 15 percent, and there has been a 45 percent increase since 1998. Such figures inevitably raise questions about the appropriateness of the care mothers are receiving. Are Canadian doctors performing too many Caesareans? If so, is this putting mothers and/or infants at risk?

For reasons nobody quite understands, C-section rates vary widely by region across Canada. For instance, in Manitoba in 2008–2009, the rate was 11 points lower (14 percent) than the national rate. CIHI has calculated that if all the provinces’ rates for primary C-sections, or C-sections for first-time mothers, were similar to Manitoba’s, 16 200 fewer Caesareans would be performed across Canada. This would represent a potential annual savings of $36 million in acute care services (CIHI, 2010).

Examining the rates in other countries, China’s rate of Caesareans increased from 5 percent in 1991 to 46 percent in 2008 (Guo et al., 2007; Juan, 2010). In the United States, the rate rose every year between 1996 and 2009 (from 21 percent to 34 percent, with notable state variations, from 22 percent in Utah to 39 percent in Florida) (Menacker & Hamilton, 2010).

Less studied is the epidural, an injection in a particular part of the spine of the labouring woman to alleviate pain. Epidurals are often used in hospital births, but they increase the rate of Caesarean sections and decrease the readiness of newborn infants to suck immediately after birth (Bell et al., 2010).

From Day One For various reasons, some countries have much higher rates of Caesarean deliveries than others. This new mother in Brazil, which has a high C-section rate, has safely delivered her baby and, with the encouragement of the hospital, is breastfeeding him from the very beginning.

AGENCIA ESTADO VIA AP IMAGES

Another medical intervention is induced labour, in which labour is started, speeded, or strengthened with a drug. The rate of induced labour in many developed nations has more than doubled since 1990, up to 20 to 25 percent. The reasons are sometimes medically warranted (such as when a woman develops eclampsia, which could kill the fetus) and sometimes not (Grivell et al., 2012). Induction increases the rate of complications, including the need for Caesareans.

Alternatives to Hospital TechnologyQuestions of costs and benefits abound. For instance, C-section and epidural rates vary more by doctor, hospital, day of the week, and region than by medical circumstances. This is partly an economic issue; in the United States, the C-section rate increases when the birth is fully covered by insurance. But it also is true in Sweden, where obstetric care is paid for by the government (Schytt & Walderenström, 2010).

Most Canadian births now take place in hospital labour rooms with high-tech facilities and equipment nearby. In 2011, 98.4 percent of Canadian births were hospital births, while 1.6 percent were non-hospital births, for example, in birthing centres or at home (Statistics Canada, 2013j). Some home births were planned while others were unexpected because labour was too quick. The latter situation is hazardous if no one is nearby to rescue a newborn in distress (Tracy, 2009).

In some European nations, many births occur at home by plan (30 percent in the Netherlands). In Europe, home births have fewer complications than in hospitals—perhaps because pregnant women requesting home births are screened to disallow those at risk (such as an older woman having twins), or perhaps because the women are more relaxed at home. In the Netherlands, special ambulances called flying storks speed mothers and newborns to hospitals if needed. Dutch research finds home births better for mothers and no worse for infants than hospital births (de Jonge et al., 2009).

In most hospitals in the twentieth century, women giving birth laboured alone. Fathers and other family members were kept away and only doctors and nurses attended the birth. No longer. Almost everyone now agrees that other people should always be with a labouring woman. Relatives or friends are often present, midwives have often replaced doctors, and sometimes a doula provides practical as well as emotional support for the mother and other family members. Many studies have found that doulas benefit anyone giving birth, rich or poor, married or not (Vonderheid et al., 2011). For example, in one study 420 middle-class married women who arrived at a hospital in labour with their husbands were randomly assigned a doula or not. Those with doulas had fewer Caesareans (13 versus 25 percent) or epidurals (65 versus 76 percent) (McGrath & Kennell, 2008).

In Canada, women can also make use of a licensed midwife instead of an obstetrician. Besides assisting at a baby’s birth, midwives provide various other services, including physical examinations and screening tests. They work in partnership with other health professionals. In 2009, midwives attended about 10 percent of all births in Ontario, and 20 percent of those births occurred at home (College of Midwives of Ontario, n.d.).

The New Family

The fact that mothers are now less lonely during labour stems in part from the recognition that people are social creatures, seeking support from their families and their societies. Birth marks the beginning of a new family; ideally, each family member—newborn, mother, and father—shares the experience.

The NewbornBefore birth, developing humans already contribute to their families via fetal movements and hormones that cause protective impulses in the mother early in pregnancy and nurturing impulses at the end (Konner, 2010). The appearance of the newborn (big hairless head, tiny feet, and so on) stirs the human heart, as is evident in adults’ brain activity and heart rates when they see a baby.

Newborns are responsive social creatures, listening, staring, sucking, and cuddling. In the first day or two after birth, a professional might administer the Brazelton Neonatal Behavioral Assessment Scale (NBAS), which records 46 behaviours, including 20 reflexes. Parents watching the NBAS are amazed at their newborn’s competence—and this fosters early parent–child connection (Hawthorne, 2009). Technically, a reflex is an involuntary response to a particular stimulus. Humans of every age reflexively seek to protect themselves (the eye blink is an example). The speed and strength of reflexes varies, even among newborns, who have three sets of protective reflexes:

• Reflexes that maintain oxygen supply. The breathing reflex begins even before the umbilical cord, with its supply of oxygen, is cut. Additional reflexes that maintain oxygen are reflexive hiccups and sneezes, as well as thrashing (moving the arms and legs about) to escape something that covers the face.
• Reflexes that maintain constant body temperature. When infants are cold, they cry, shiver, and tuck their legs close to their bodies. When they are hot, they try to push away blankets and then stay still.
• Reflexes that manage feeding. The sucking reflex causes newborns to suck anything that touches their lips—fingers, toes, blankets, and rattles, as well as natural and artificial nipples of various textures and shapes. The rooting reflex causes babies to turn their mouths toward anything that brushes against their cheeks—a reflexive search for a nipple—and start to suck. Swallowing is another reflex that aids feeding, as is crying when the stomach is empty and spitting up when full.

Each of these 13 reflexes (in italics) normally causes a caregiving reaction, as the new parents do what seems necessary to protect their newborn. Thus reflexes affect human interaction. In addition, newborn senses are also responsive to people: New babies listen more to voices than to traffic, for instance, and they stare at faces more than at machines. Typically, when a baby stares at a new parent, the parent talks and the baby listens.

Never Underestimate the Power of a Reflex For developmentalists, newborn reflexes are mechanisms for survival, indicators of brain maturation, and vestiges of evolutionary history. For family members, they are mostly delightful and sometimes amazing. Both of these viewpoints are demonstrated by star performer Wyatt, who was born on March 1, 2013 in Brampton, Ontario. He is seen here sucking peacefully on his finger; grasping the finger of his big sister, Nicole; and stepping eagerly forward on legs too tiny to support his body.

SHEILA TRINIDAD AND JAMES FOX

A Good Beginning The joy and bonding between this expectant couple and their unborn child is a wonderful sign. Their alliance is crucial for the healthy social and emotional development of their child.

MIKA/CORBIS

New FathersFrom conception on, fathers’ involvement in their children’s lives is vitally important and has a strong impact on children’s development. Fathers-to-be help mothers-to-be stay healthy, nourished, and drug-free. They are present at ultrasounds and they help with the labour and birth. Some fathers-to-be even have their own biological and psychological experiences with pregnancy and birth, in a condition known as couvade. For example, levels of stress hormones correlate between expectant fathers and mothers, probably because they reflect each others’ emotions (Berg & Wynne-Edwards, 2002). Beyond that, many fathers experience weight gain and indigestion during pregnancy and pain during labour. Indeed, among some Latin American indigenous peoples, fathers go through the motions of labour when their wives do, to help ensure an easy birth.

After their children’s birth, fathers are involved in the day-to-day care of their infants. This active involvement—a shift from the days when a father’s main role was as breadwinner—can partially be explained by the less traditional division of roles and responsibilities of mothers and fathers, including the increased participation of women in the labour force, and by fathers’ wanting to be closer to their children (Beaupré et al., 2010). In addition, some researchers suspect that a general cultural shift and changing attitudes toward parenting roles is partly responsible for the greater number of fathers who are primary caregivers to their children (Marshall, 2008).

In Canada, fathers’ increased use of paid parental leave from work is evidence of their increased involvement in the care of their children. In 2000, only 3 percent of eligible Canadian fathers took this time off, but by 2006 the rate had increased to 20 percent. A large part of the increase was due to rule changes, especially in Quebec where the provincial government instituted a “daddy days” policy that allows for up to five weeks of paid paternal leave that cannot be transferred to the mother.

The move away from traditional parenting roles is evident among European-Canadians as well as among the country’s immigrant communities. For example, one recent study found that Chinese-Canadian fathers are actively involved in rearing their young children, and their direct involvement ranges from playing with and caring for their infants and toddlers to cooperating with mothers on making decisions about child care (Chuang & Su, 2009).

New MothersAbout half of all women experience physical problems after giving birth, such as incisions from a C-section, painfully sore nipples, or problems with urination (Danel et al., 2003). However, worse than any physical problems are psychological ones. When the birth hormones decrease, between 8 and 15 percent of women experience postpartum depression, a sense of inadequacy and sadness (called baby blues in the mild version and postpartum psychosis in the most severe form) (Perfetti et al., 2004). With postpartum depression, baby care (feeding, diapering, bathing) feels very burdensome.

Sometimes the first sign that something is amiss is that the mother is euphoric after birth. She cannot sleep, stop talking, or keep from worrying about the newborn. Some of this is normal, but family members and medical personnel need to be alert, as a crash might follow the high.

Maternal depression can have a long-term impact on the child, one of the many reasons why postpartum depression should be quickly recognized and treated. Fathers are usually the first responders; they may be instrumental in getting the help the mother and baby need (Cuijpers et al., 2008; Goodman & Gotlib, 2002). This is easier said than done. Fathers may become depressed as well; in such cases, other people need to step in.

From a developmental perspective, causes of postpartum depression (such as marital problems) sometimes predate pregnancy; others (such as financial stress) occur during pregnancy; others correlate with birth (especially if the mother is alone); and still others (health, feeding, or sleeping problems) are specific to the particular infant. Successful breastfeeding may mitigate maternal depression, in part by increasing levels of oxytocin, a bonding hormone. This is one of the many reasons a lactation counsellor (who helps with breastfeeding techniques) may be a crucial member of the new mother’s support team.

A Teenage Mother This week-old baby, born in an economically disadvantaged village in Myanmar (Burma), has a better chance of survival than he might otherwise have had because his 18-year-old mother has bonded with him.

SHEHZAD NOORANI/AGE FOTOSTOCK

BondingThe active involvement of both parents in pregnancy, birth, and newborn care helps establish the parent-infant bond, the strong, loving connection that forms as parents hold, examine, and feed their newborn. Factors that encourage parents (biological or adoptive) to nurture their newborns have lifelong benefits, proven with mice, monkeys, and humans (Champagne & Curley,2010).

Early skin-to-skin contact, which was welcomed a few decades ago because it reduced the impersonal medicalization of hospital births, helps establish this bond. The importance of this contact has recently become apparent with kangaroo care, in which the newborn lies between the mother’s breasts, skin-to-skin, listening to her heartbeat and feeling her body heat. Many studies find that kangaroo-care newborns sleep more deeply, gain weight more quickly, and spend more time alert than do infants with standard care (Ludington-Hoe, 2011).

Kangaroo care was first used with low-birth-weight newborns, but it also benefits healthy newborns. Fathers also can provide kangaroo care, benefitting babies and themselves (Feeley et al., 2013). Months later, infants who are given kangaroo care tend to flourish, either because of improved infant adjustment to life outside the womb or because of increased parental sensitivity and effectiveness. Probably both. Oxytocin is released during kangaroo care, which is beneficial for everyone (Ludington-Hoe, 2011).

A Beneficial Beginning This new mother in a maternity ward in Manila is providing her baby with kangaroo care.

PAULA BRONSTEIN/GETTY IMAGES