Pregnancy presents substantial health risks, even in developed countries, and despite advances in obstetrical science and practice.[34] Maternal mortality remains a major problem in global health and is considered a sentinel event in judging the quality of health care systems.[35] Adolescent pregnancy represents a particular problem, whether intended or unintended, and whether within marriage or a union or not. Pregnancy results in major changes in a girl's life, physically, emotionally, socially and economically and jeopardises her transition into adulthood. Adolescent pregnancy, more often than not, stems from a girl's lack of choices. or abuse. Child marriage (see below) is a major contributor worldwide, since 90% of births to girls aged 15–19 occur within marriage.[36]
A related issue is the inclusion of pregnant women in clinical studies. Since other illnesses can exist concurrently with pregnancy, information is needed on the response to and efficacy of interventions during pregnancy, but ethical issues relative to the fetus, make this more complex. This gender bias is partly offset by the iniation of large scale epidemiology studies of women, such as the Nurses' Health Study (1976),[162] Women's Health Initiative[163] and Black Women's Health Study.[164][6]
Low-fat dairy products are excellent sources of calcium. Other good sources of calcium include salmon, tofu (soybean curd), certain vegetables (broccoli), legumes (peas and beans), calcium-enriched grain products, lime-processed tortillas, seeds and nuts. If you do not regularly consume adequate food sources of calcium, a calcium supplement can be considered to reach the recommended amount. The current recommendations for women for calcium are for a minimum of 1,200 mg per day.

Nutrition is particularly important during pregnancy to ensure your health and the health of the baby. It's normal to gain weight during pregnancy—not just because of the growing fetus, but because you'll need stored fat for breast-feeding. The Institute of Medicine (IOM) recommends a gain of 25 to 35 pounds in women of normal weight when they get pregnant; 28 to 40 pounds in underweight women; and at least 15 pounds in women who are overweight when they get pregnant. The IOM has not given a recommendation for an upper limit for obese women, but some experts cap it as low as 13 pounds. If you fit into this category, discuss how much weight you should gain with your health care professional.
In addition to diet, exercise and other lifestyle factors can also play an important role in bone health. Smoking and drinking too much alcohol can increase your chances of developing osteoporosis, while weight-bearing exercise (such as walking, dancing, yoga, or lifting weights) can lower your risk. Strength or resistance training—using machines, free weights, elastic bands, or your own body weight—can be especially effective in helping to prevent loss of bone mass as you age.